Endocrine Surgery MCQ 1. When progressive enlargement of a multinodular goiter causes symptomatic tracheal compression, the preferred management in otherwise good-ris patients is! ". #odine treatment. $. %hyroid hormone treatment. C. Surgical resection of the a&normal thyroid. '. (adioactive iodine treatment. "nswer! C
'#SC)SS#*+! When a multinodular goiter enlarges enough to cause symptoms of tracheal compression, surgical treatment is usually reuired if the patient is considered a reasona&le operative ris. Medical treatment may &e effective in preventing the initial growth of the goiter &ut is unliely to cause enough regression to relieve symptoms. (adioactive iodine can occasionally &e used to cause some regression in patients who are poor anesthesia riss, &ut this is a temporiing treatment rather than a definitive one.
. %he most precise diagnostic screening procedure for differentiating &enign thyroid nodules from malignant ones is! ". %hyroid ultrasonography. $. %hyroid scintiscan. C. /ine-needle-aspiration &iopsy 0/+"$. '. %hyroid hormone suppression. "nswer! C '#SC)SS#*+! "nalysis of multiple series in which patients with thyroid nodules have undergone /+"$ has demonstrated a false-negative rate of
.23 and a false-positive rate of 4.43. Sensitivity for this method is 536 specificity 723. %his surpasses the other methods for accurate selection of patients who reuire surgical resection.
4. %he preferred operation for initial management of a thyroid nodule that is considered suspicious for malignancy &y /+"$ is! ". E8cision. $. 9artial lo&ectomy. C. %otal lo&ectomy and isthmusectomy. '. %otal thyroidectomy. "nswer! C '#SC)SS#*+! %here is a consensus that the initial minimum operation for a nodule suspected to &e malignant is total lo&ectomy and isthmusectomy. 9artial lo&ectomy or e8cision of the nodule is associated with a higher ris of local recurrence if the nodule proves to &e malignant. (eoperation on the side of a partial lo&ectomy can &e technically difficult and associated with a higher ris of recurrent nerve in:ury. *rdinarily, total thyroidectomy is not performed until a conclusive diagnosis of malignancy is esta&lished.
2. "dvantages of total thyroidectomy for management of papillary carcinomas of the thyroid larger than 1.; cm. include! ". 9ossi&ility of using radioactive iodine postoperatively to identify and treat metastases. $. %he a&ility to use thyroglo&ulin levels as a marer for recurrence. C.
efficiently &ecause of the a&sence of normal thyroid tissue, which has greater affinity for iodine than papillary carcinoma tissue. When all normal thyroid tissue is removed, serum thyroglo&ulin, which is produced &y normal and malignant thyroid tissue, &ecomes a more effective marer for recurrence. %he overall recurrence rate is lower for patients undergoing total thyroidectomy, &ut the ris of hypoparathyroidism is higher for patients who have total thyroidectomy instead of unilateral lo&ectomy.
;. Which of the following statements a&out follicular carcinoma is=are true> ". #t presents at a later age than papillary carcinoma. $. #t disseminates via hematogenous routes. C. #t is the most common type of well-differentiated thyroid carcinoma. '. E8tensive angioinvasion portends a poor prognosis. E. /ollicular carcinomas are freuently multicentric. "nswer! "$' '#SC)SS#*+! /ollicular carcinoma is more common in older patients 0pea incidence in the fifth decade. %he tumor has a mared propensity for vascular invasion and spreads hematogenously to &one, lung, liver, and central nervous system sites.
?. " familial form of medullary thyroid carcinoma 0M%C should &e suspected whenever! ". %he tumor is multifocal. $. %he tumor is &ilateral 0foci of tumor are present in &oth thyroid lo&es. C. 9athologic e8amination of the resected thyroid gland reveals the presence
of C-cell hyperplasia in areas of the gland ad:acent to foci of M%C. '. "ll of the a&ove. "nswer! ' '#SC)SS#*+! Sporadic M%C is unilateral in at least @A3 of cases. Bowever, in patients with M%C occurring as a component of the multiple endocrine neoplasia 0ME+ type " or type $ syndromes, the tumor is virtually always multifocal and &ilateral. %ypically, in this setting the M%C appears as multiple whitish-tan tumor nodules in the middle and upper thirds of each thyroid lo&e. " diffuse premalignant proliferation of the C cells of the thyroid is thought to precede the development of M%C in patients with familial M%C. %his proliferation, nown as C-cell hyperplasia 0CCB, consists of parafollicular clusters of increased num&ers of C cells. %he finding of CCB in areas of the thyroid ad:acent to gross foci of M%C is strong evidence for familial M%C.
7. "ll of the following are components of the ME+ type $ syndrome e8cept! ". Multiple neuromas on the lips, tongue, and oral mucosa. $. Byperparathyroidism. C. M%C. '. 9heochromocytoma. "nswer! $ '#SC)SS#*+! M%C and pheochromocytoma occur in &oth ME+ " and ME+ $ syndromes. 9atients with ME+ " may also develop hyperplasia of the parathyroid glands. "lthough some investigators have reported euivocal histologic a&normalities in the parathyroid glands of patients with ME+ $, hyperparathyroidism is not a component of this syndrome. #n contrast to patients with ME+ ", those with ME+ $ have a characteristic phenotype, including a tall, thin marfanoidD ha&itus. 9atients
with ME+ $ also develop multiple neuromas on the lips, tongue, and oral mucosa, creating the appearance of thic lips.
@. ME+ " and ME+ $ syndromes are associated with germline mutations in! ". %he p;4 tumor suppressor gene. $. %he B-ras gene. C. %he +-myc gene. '. %he (E% proto-oncogene. "nswer! ' '#SC)SS#*+! ermline mutations in the (E% protooncogene, a receptor tyrosine inase that maps to chromosome 1A, are associated with ME+ " and ME+ $ syndromes. Bomoygous loss of the tumor suppressor gene p;4 is associated with the
5. Which of the following are true concerning islet cell neoplasms of the pancreas in patients with ME+ type 1> ". #slet cell neoplasms in patients with ME+ 1 are characteristically multicentric. $. %he most common islet cell neoplasm in patients with ME+ 1 is gastrinoma. C. #slet cell neoplasms in patients with ME+ 1 may &e malignant. '. "ll of the a&ove. "nswer! '
'#SC)SS#*+! %he pathologic change in the pancreas of patients with ME+ 1 is typically multicentric. 'iffuse hyperplasia of islet cells and microadenoma formation are often identified in areas of the gland distant from grossly evident tumor. %umors are commonly multifocal. #slet cell neoplasms of the pancreas occur in 4A3 to @A3 of patients with ME+ 1. %he most common islet cell neoplasm in these patients is gastrinoma. astrinomas associated with ME+ 1 pro&a&ly account for A3 to ;A3 of all cases of the Follinger-Ellison syndrome. %he second most common islet cell tumor is insulinoma. *ther pancreatic islet cell neoplasms, such as glucagonoma, somatostatinoma, or vasoactive intestinal polypeptide neoplasm 0G#9oma, are rarely associated with ME+ 1. "ppro8imately 1A3 of insulinomas and appro8imately 1;3 or more of gastrinomas in patients with ME+ 1 are malignant.
1A. Which of the following statements a&out the differential diagnosis of hypercalcemia is=are correct. ". Malignant tumors typically cause hypercalcemia &y ectopic production of parathyroid hormone 09%B. $. %he diagnosis of primary hyperparathyroidism is supported &y these serum levels! calcium, 1A.@ mg. per dl.6 chloride, 1A2 mmol. per liter6 &icar&onate 1 mmol. per liter6 phosphorus, .2 mg. per dl.6 elevated parathyroid hormone. C. /amilial hypocalciuric hypercalcemia is distinguished from primary hyperparathyroidism &y parathyroid imaging. '. "lthough serum al&umin &inds calcium, the measured total calcium value is usually unaffected in patients with severe hypoproteinemia. E. %hiaide diuretics are a good treatment for hypercalcemia and can &e given to patients with apparent hypercalcemia of malignancy. "nswer! $ '#SC)SS#*+! Malignant tumors rarely secrete 9%B itself6 they can secrete
9%Br9 or cytoine activators of osteoclast activity. %he diagnosis of primary hyperparathyroidism is supported &y hypercalcemia with mild hyperchloremic meta&olic acidosis and a chloride-phosphate ratio greater than 44 or a modified chloride 0mmol. per liter=mg. per dl. phosphate ratio greater than ;AA. /amilial hypocalciuric hypercalcemia is distinguished from primary hyperparathyroidism &y a low urine calcium. Serum calcium changes appro8imately A.@ mg. per dl. for every 1 gm. per dl. change in serum al&umin. %hiaide diuretics can cause hypercalcemia and should not &e given to patients who are hypercalcemic.
11. #ndications for operation in a patient with previously asymptomatic hyperparathyroidism include! ". "ge older than ?A. $. +ephrolithiasis. C. " su&stantial decline in renal function. '. " su&stantial decline in &one mass. E. 'epression and fatigue. "nswer! $C'E '#SC)SS#*+! "ge younger than ;A is considered an indication for operation.
1. %he parathyroid glands! ". 'evelop from the second and third pharyngeal pouches, along with the palatine tonsil and the thymus. $. Migrate caudally in the nec in normal development &ut can &e found anywhere from the pharyngeal mucosa to the deep mediastinum. C. Secrete 9%B and calcitonin to manage calcium homeostasis. '. )sually num&er four, &ut freuently num&er only two or three. E. Contain enymes that catalye the conversion of ;0*B vitamin ' 4 to
1,;0*B vitamin ' 4. "nswer! $ '#SC)SS#*+! %he parathyroid glands develop from the third and fourth pharyngeal pouches, along with the thymus and the thyroid ultimo&ronchial &ody6 there are four glands in the vast ma:ority of persons. Calcitonin is secreted &y the C cells of the thyroid. Gitamin ' 4 hydro8ylation occurs in the idney.
14. Byperparathyroidism can affect which of the following organs and &ody systems> ". astrointestinal tract. $. Hidneys. C. Seleton. '. +euromuscular system. E. Cardiovascular system. "nswer! "$C'E '#SC)SS#*+! astrointestinal involvement includes pancreatitis and peptic ulcer disease. %he idneys can &e affected &y nephrocalcinosis or nephrolithiasis. %he &ones can &e severely affected &y &one resorption. +euromuscular complaints can include weaness and fatigue. Bypertension is present in as many as 7A3 of people with hyperparathyroidism and may &e related to the renal disease.
12. Secondary hyperparathyroidism! ". #s a meta&olic disease in which the primary a&normality is decreased glomerular filtration rate. $. #s &est treated initially &y su&total parathyroidectomy. C. #s caused &y increased production of 1,;0*B vitamin ' 4, causing
increasing intestinal calcium a&sorption and hypercalcemia. '. Can have severe effects on &ones e8acer&ated &y aluminum contained in phosphate &inders and dialysate water. E. #s &est treated initially &y total parathyroidectomy with autotransplantation. "nswer! "' '#SC)SS#*+! Secondary hyperparathyroidism is caused &y renal disease, including decreased glomerular filtration rate and decreased 1,;0*B vitamin ' 4 production. #t is &est treated &y medical management restricting dietary phosphate, administering vitamin ' and calcium with phosphate&inding gels, and limiting aluminum e8posure, which can e8acer&ate &one disease.
1;. Bypoparathyroidism! ". #s most commonly encountered as a postviral syndrome. $. Can &e associated with mared hypocalcemia after parathyroidectomy in patients with &one disease. C. Can cause an8iety, depression, or confusion. '. Can cause physical signs such as ChvosteIs and %rousseauIs signs. E. #s treata&le acutely with intravenous calcium salts and chronically with oral calcium and vitamin '. "nswer! $C'E '#SC)SS#*+! Bypoparathyroidism is most commonly encountered after thyroid surgery. #t can &e temporarily severe after parathyroidectomy in patients with &one disease 0postoperative &one hungerD. %he signs and symptoms can include an8iety, depression, confusion, ChvosteIs sign, and %rousseauIs sign, as well as circumoral or e8tremity tingling, tetany with carpopedal spasms, or seiures. %reatment is as noted.
1?. %rue statements a&out pituitary anatomy and physiology include! ". %he pituitary has dual em&ryonic srcin! the anterior pituitary arises from em&ryonic ectoderm6 the posterior pituitary, from the diencephalon. $. %he hypophyseal portal system integrates function of the anterior and posterior pituitary. C. "drenocorticotropin 0"C%B, formed &y posttranslational processing of the precursor 9*MC, is normally controlled &y hypothalamic C(/ &ut may &e released &y immune-related mechanisms. '. rowth hormone 0B directly stimulates longitudinal growth of the seleton and growth of muscles. E. Cell types of the anterior pituitary are classified &y their position in the anterior pituitary and &y their staining characteristics with histologic dyes. "nswer! "C '#SC)SS#*+! %he anterior pituitary arises from (atheIs pouch 0em&ryonic ectoderm, and it includes the pars distalis, pars intermedia, and pars tu&eralis. %he posterior pituitary arises from the diencephalon and includes the neural stal, infundi&ulum, and posterior lo&e. %he hypophyseal portal system drains from the hypothalamus and integrates function of the hypothalamus and anterior pituitary &y carrying hypothalamus-derived releasing factors to target cells in the anterior pituitary. "C%B may &e released during stress in response to interleuin-1, -, and -?. Somatotrophic actions of B are indirect and are mediated &y the insulinlie growth factors formerly nown as somatomedins. Current classification of anterior pituitary cells is &ased on immunochemical identification of their secretory products 0i.e., corticotropes produce "C%B, lactotropes produce prolactin, and thyrotropes produce thyroid-stimulating hormone J%SBK.
17. "ntidiuretic hormone 0"'B! ". #s related to o8ytocin, and &oth are released from the posterior pituitary in
con:unction with neurophysins. $. #s released into the circulation &y the posterior pituitary in response to a rise in plasma osmolality a&ove @; m*sm. or a decrease in circulating &lood volume. C. May &e stimulated &y catecholamines and inhi&ited &y phenytoin, alcohol, and lithium. '. #n e8cess, may produce a syndrome of euvolemic hyponatremia with inappropriately concentrated urine that is responsive to free water restriction. E. 'eficiency causes prolonged polyuria and polydipsia and may &e diagnosed &y a com&ination of high plasma osmolality and low urine osmolality following water deprivation. "nswer! "$C'E '#SC)SS#*+! "'B and o8ytocin are nineLamino acid peptides derived from a common ancestral peptide, vasotocin. "'B is released from the posterior pituitary with neurophysin ## in response to a rise in plasma osmolality greater than @; m*sm=g. B *. &y a ;3 or greater decrease in &lood volume, and &y catecholamines. %he syndrome of inappropriate "'B release 0S#"'B produces euvolemic hyponatremia and is responsive to free water restriction. 'ia&etes insipidus 0'# reflects a deficiency of "'B and causes prolonged polyuria and polydipsia. 'ia&etes insipidus is diagnosed &y a com&ination of high plasma osmolality and low urine osmolality following water deprivation. E8ogenously administered "'B differentiates central 0"'B-responsive '# from nephrogenic 0"'B-unresponsive '#.
1@. Signs and symptoms of acute pituitary apople8y include! ". Severe headache. $. Meningismus. C. Gision loss. '. Shoc. E. May &e relieved &y emergent transsphenoidal decompression of the sella
turcica. "nswer! "$C' '#SC)SS#*+! "cute pituitary apople8y follows sudden hemorrhage into a pre-e8isting pituitary tumor or following closed head trauma. Symptoms, including headache, meningismus, and vision loss, are attri&uta&le to the intracere&ral &lood. 9ituitary insufficiency, as well as the accompanying secondary adrenal insufficiency, may cause hypotension and shoc. *ther manifestations may include '# and my8edema. "cute pituitary apople8y is a neurosurgical emergency that reuires transsphenoidal decompression of the sella turcica.
15. 9rolactinomas of the pituitary! ". Most often produce dysfunctional uterine &leeding in women. $. Most commonly produce infertility in men. C. When asymptomatic, are &est treated surgically early in the microadenoma stage. '. May enlarge during pregnancy, reuiring treatment with &romocriptine or surgery. E. Commonly occur in patients with ME+ . "nswer! ' '#SC)SS#*+! 9ituitary prolactinomas are the most common pituitary tumor and cause amenorrhea, galactorrhea, or &oth in women. Men usually have macroprolactinomas and e8perience symptoms of a space-occupying lesion of the sella 0i.e., headache. " minority of men e8perience impotence and infertility. "symptomatic prolactinomas remain sta&le over time and reuire o&servation only. Symptomatic prolactinomas reuire treatment, usually with &romocriptine. 9rolactinomas may enlarge during pregnancy and can produce symptoms reuiring treatment with either &romocriptine or surgery. 9rolactiomas are seen in as many as 2A3 of patients with ME+ 1.
A. Bypercortisolism! ". #s most often "C%B-dependent, owing to an "C%B-producing pituitary adenoma. $. #s &est diagnosed &y measurement of cortisol from a serum sample collected at @ ".M. C. #s attri&uta&le to an adrenal source if the &asal serum "C%B level is a&ove 1A pg. per ml., if the hypercortisolism is suppressed &y high-dose de8amethasone, and if an adrenal tumor is visualied radiographically. '. May &e caused &y small cell carcinoma of the lung, carcinoid tumors, tumors of the endocrine pancreas, pheochromocytoma, or medullary thyroid carcinoma 0M%C. E. #n children is most often caused &y adrenocortical neoplasia. "nswer! "'E '#SC)SS#*+! CushingIs syndrome is most often 0@A3 to 5A3 "C%Bdependent and is most often due to an "C%B-secreting pituitary adenoma 0CushingIs disease. Some 1A3 to A3 of "C%B-dependent CushingIs syndrome is caused &y ectopic production of "C%B from small cell carcinoma of the lung, carcinoid tumors, tumors of the endocrine pancreas, pheochromocytoma, and M%C. "C%B-independent CushingIs syndrome secondary to primary adrenal pathology occurs in 1A3 to A3 of cases in adults and is the most common form in children. Measurement of cortisol in two to three consecutive 2-hour collections of urine is the &est screening test for CushingIs syndrome! plasma levels of cortisol show mared varia&ility, and a single random level is not helpful in esta&lishing the diagnosis. "C%Bindependent CushingIs syndrome suppresses the pituitary and is diagnosed if the &asal serum "C%B level is suppressed &elow ; pg. per ml., if the hypercortisolism is not suppressed &y high-dose de8amethasone, or if the metyrapone stimulation test is negative. %he de8amethasone suppression and metyrapone tests do not, however, distinguish an adrenal from an ectopic
"C%B cause of CushingIs since &oth suppress the pituitary. (adiographic evidence of an adrenal tumor must &e supported &y &iochemical testing to confirm that the adrenal is the primary cause of CushingIs syndrome.
1. 9rimary aldosteronism! ". 9roduces a syndrome of diastolic hypertension, hypoalemia, and edema. $. #s suggested &y findings of serum potassium less than 4.; mE. per liter, urinary potassium e8cretion greater than 4A mE. per day, upright plasma renin &elow 4 ng. per ml., and a plasma aldosterone concentrationLplasma renin activity ratio greater than A!1. C. #s most often due to an aldosterone-producing adrenal adenoma, which may &e distinguished from idiopathic adrenal hyperplasia &y its sensitivity to diurnal changes in "C%B and insensitivity to changes in posture. '. May &e diagnosed in hypertensive patients &y demonstration of an adrenal mass larger than 1 cm. on computed tomography alone. E. #s &est treated surgically if it is due to either aldosteronoma or idiopathic adrenal hyperplasia. "nswer! $C '#SC)SS#*+! 9rimary aldosteronism is a syndrome of diastolic hypertension and hypoalemia6 edema typically is a&sent. %he diagnosis relies on demonstration of hypoalemia with inappropriate aliuresis and inappropriately elevated plasma aldosterone with suppression of plasma renin following sodium loading. 9rimary aldosteronism most often is due to an adrenal adenoma, which must &e distinguished from idiopathic adrenal hyperplasia since resection of the adenoma is nearly always curative, whereas adrenal resection for idiopathic adrenal hyperplasia is curative less than A3 of the time. C% evidence of adrenal tumor alone is inadeuate to diagnose aldosteronism, even in a hypertensive patient.
. "drenocortical carcinoma! ". May &e suspected in a patient with rapidly progressive CushingIs syndrome and viriliing features or in asymptomatic patients with adrenal tumors larger than ? cm on C%. $. Most often is diagnosed early in its course when disease is confined to the adrenal gland. C. #s differentiated from &enign adrenocortical adenoma &y tumor necrosis, hemorrhage, and cellular features of large hyperchromatic nuclei and more than A mitoses per high-power field. '. Should &e resected only if disease is localied to the adrenal gland6 otherwise treatment with mitotane is indicated. E. Carries a poor prognosis! overall ;-year survival less than ;3. "nswer! "E '#SC)SS#*+! 9atients with adrenocortical carcinoma often present with rapidly progressive syndromes of com&ined adrenocortical hormone e8cess. Bowever, appro8imately half do not have syndromes of hormone e8cess &ut present with a&dominal pain, increased a&dominal girth, weight loss, and anore8ia. /urthermore, incidentally discovered adrenal masses larger than ? cm. har&or carcinoma in as many as 53 of cases. "drenocortical carcinoma is differentiated from adenoma &y pathologic demonstration of either local invasion or distant metastases. Most patients with adrenocortical carcinoma present with locally advanced 0stage ### or metastatic 0stage #G disease. 9rognosis for these patients is poor! ;-year survival is less than ;3 in most series. 9atients with adrenocortical carcinoma should undergo primary surgical resection or palliative surgical de&uling of locally advanced, metastatic, or even recurrent disease since response of these tumors to medical therapy, including mitotane, is poor.
4. "ddisonian crisis, or acute adrenocortical insufficiency! ". *ccurs only in patients with nown adrenal insufficiency or in those
receiving long-term supraphysiologic doses of e8ogenous steroids. $. Can mimic an acute a&domen with fever, nausea and vomiting, a&dominal pain, and hypotension. C. May cause electrolyte a&normalities, including hypernatremia, hypoalemia, hypoglycemia, and hypercalcemia, as well as eosinophilia on peripheral &lood smear. '. Should &e diagnosed with the rapid "C%B stimulation test &efore steroid replacement is instituted. E. May &e effectively treated with intravenous stress-doseD glucocorticoid and mineralocorticoid replacement. "nswer! $ '#SC)SS#*+! "ddisonian crisis, or acute adrenal insufficiency, may &e seen following even mild illness in patients with suppression of the hypothalamicpituitary-adrenal a8is. %his suppression can &e produced &y as little as 1 wee of supraphysiologic stress dose steroids in the year &efore the stressful event. "ddisonian crisis is a medical emergency that reuires prompt treatment &ased on clinical suspicion. Clinical findings include fever, nausea and vomiting, a&dominal pain, and hypotension.
2. 9reparation for surgical removal of a pheochromocytoma includes! ". $eta-adrenergic &locade followed &y alpha-adrenergic &locade.
$. Bydration. C. "lpha-adrenergic &locade, with or without &eta-adrenergic &locade. '. 9reoperative Swan-an monitoring in all patients. E. 9lanning removal through an anterior, posterior, or laparoscopic approach &ased upon tumor localiation with C%, magnetic resonance imaging 0M(#, and=or 141#-M#$. "nswer! $CE '#SC)SS#*+! 9rinciples of preoperative management for pheochromocytoma include preoperative alpha-adrenergic &locade using pheno8y&enamine or phentolamine. $eta-adrenergic &locade with propranolol is then used selectively in patients who develop tachycardia, have a history of cardiac arrhythmia, or have primarily epinephrine-secreting tumors. $eta-adrenergic &locade should &e undertaen only after successful alpha &locade is esta&lished. 9atients with pheochromocytoma freuently e8hi&it intravascular volume depletion, and careful hydration is mandatory. Central venous pressure monitoring alone is helpful to guide hydration6 more intensive monitoring with a Swan-an catheter is indicated for patients with pre-e8isting heart disease. /ormerly, the anterior approach was preferred for adrenalectomy as it facilitated complete a&dominal e8ploration and search for e8tra-adrenal pheochromocytoma. "ccurate preoperative localiation with C%, M(#, and 141#-M#$ has allowed selective use of the posterior, or even the laparoscopic, approach for adrenalectomy.
;. #ndications for surgical adrenalectomy include! ". "n adrenal mass larger than ? cm. $. Bypertensive patients with aldosteronism that is "C%B insensitive and posture sensitive and who also have multiple adrenal nodules on C%. C. CushingIs syndrome secondary to adrenal neoplasms or to persistent ectopic "C%B syndrome when the primary tumor is inopera&le. '. 9heochromocytoma in adults and children.
E. Congenital adrenal hyperplasia secondary to 1-hydro8ylase deficiency. "nswer! "C' '#SC)SS#*+! "drenalectomy is indicated for the management of adrenal masses larger than ? cm. on C% since tumors of this sie har&or carcinoma in more than 5A3 of cases. Surgical adrenalectomy is also the treatment of choice for primary adrenal causes of CushingIs syndrome. Surgical adrenalectomy may &e considered as an alternative to medical adrenalectomy with metyrapone, aminoglutethimide, or mitotane in patients with ectopic "C%B syndrome when treatment of the primary tumor is unsuccessful. 9atients with aldosteronism that is "C%B sensitive and posture insensitive liely have an adrenal adenoma that is cura&le &y adrenalectomy. "ldosteronism that is "C%B insensitive and posture sensitive is liely caused &y idiopathic adrenal hyperplasia, which is &est managed medically with spironolactone, triamterene, amiloride, or nifedipine. "drenalectomy following preoperative alpha-adrenergic &locade, with or without &etaadrenergic &locade, and hydration is the treatment of choice of all pheochromocytomas. "drenalectomy is not indicated in the management of any of the congenital adrenal hyperplasias.
?. #ncidental adrenal masses! ". May &e seen in as many as 1A3 of a&dominal C% studies. $. Most commonly represent pheochromocytoma6 adrenocortical adenoma, adrenocortical carcinoma, and metastases from other primary cancers occur less freuently. C. May represent adrenocortical carcinoma if greater than ? cm. in diameter. '. Should &e routinely evaluated &y measurement of 2-hour urine levels of catecholamines and their meta&olites, cortisol, and aldosterone plus fineneedle aspiration. E. Should &e resected if &iochemically active, if greater than ? cm., or if they grow over si8 monthsI follow-up.
"nswer! CE '#SC)SS#*+! %he incidental adrenal mass is seen in as many as 1.43 of a&dominal C% scans performed for other reasons. "drenocortical adenomas are most common, followed &y adrenocortical carcinoma, metastases from other primary cancers, and pheochromocytoma. $iochemical evaluation must weigh the prevalence of adrenal neoplasms against the conseuences of a missed life-threatening diagnosis, as in pheochromocytoma. "ll adrenal masses should &e evaluated for pheochromocytoma with measurement of 2hour urine catecholamines and their meta&olites. "ldosterone and cortisol measurement are indicated if clinical features suggest aldosteronism or CushingIs syndrome. /ine-needle aspiration of adrenal masses is indicated for clearly cystic lesions or if metastasis is suspected &ased on the presence of another nown primary. /ine-needle aspiration is not routinely indicated in the evaluation of adrenal lesions and is contraindicated until pheochromocytoma is definitively e8cluded. "drenal lesions should &e resected if they are functional, are larger than ? cm., or have enlarged during follow-up.
7. Which of the following statements is true a&out the synthesis of thyroid hormone and its physiology> ". %he iodine utilied in hormone synthesis is derived principally from dietary sources. $. %he role of thyroid-stimulating hormone 0%SB in thyroid physiology is limited to regulation of the release of thyroid hormone in plasma. C. Enough thyro8ine 0% 2 is stored in the normal thyroid to provide a euthyroid state for 4 wees despite a&sence of iodine intae. '. %he regulation of thyroid function involves pituitary, &ut not hypothalamic, input. "nswer! "C
'#SC)SS#*+! #odine is necessary for the synthesis of thyroid hormone, and appro8imately AA to ;AA mg is ingested daily. Most of it is a&sor&ed from the small intestine and is cleared from the plasma &y secretion of thyroid hormone. %SB is reuired for the normal production and secretion of thyroid hormone. #t is generally accepted that %SB also has a ma:or role in thyroid growth. %he thyroid gland has a storage reserve of appro8imately 4 wees. %he principal regulatory mechanisms of the thyroid gland are the hypothalamic-pituitary-thyroid control system and the intrathyroidal regulatory systems. %(B is produced &y the superoptic and paraventricular nuclei within the hypothalamus and passes down their a8ones. /ollowing secretion into the hypophyseal portal &lood systems %(B passes to the pituitary and induces stimulation of %SB secretion.
@. Correct statements a&out thyroid function tests include which of the following> ". Contraceptive pills and pregnancy increase the amount of thyro8in&inding glo&ulin 0%$, and, conseuently, the total % 2 level. $. "nticonvulsive medications and chronic de&ilitating illnesses decrease the amount of %$ and, conseuently, the total % 2 level. C. #ntravenous pyleography can lower the rate of active iodine uptae &y the thyroid. '. " triiodothyronine 0% 4 suppression test that demonstrates nonsuppressi&ility of thyroid function is compati&le with the diagnosis of ravesI disease, to8ic adenoma, or functioning carcinoma. E. "n increased serum cholesterol level in a hypothyroid patient indicates a thyroid cause. "nswer! "$C' '#SC)SS#*+! Bormone &inding proteins are the principal intravascular factors influencing total hormone concentration. Garious factors may cause changes in the concentration of %$. Contraceptive pills and pregnancy
increase the amount of %$, while anticonvulsive medications and chronic de&ilitating disease may decrease the amount of %$. "dministration of e8cess amounts of iodine may lower the rate of active iodine uptae in the thyroid gland. %he thyroid suppression test is &ased on the principle that administration of thyroid hormone does not suppress the patientIs thyroid function when normal homeostatic mechanisms are disrupted. %hyroid function is nonsuppressi&le in hyperthyroidism or in the presence of thyroid hormoneLsecreting tumors. Serum cholesterol, deep tendon refle8 time, and cardiovascular functions can &e measured to reflect hypothyroidism and hyperthyroidism &ut do not give an indication of the etiology of hypothyroidism.
5. Byperthyroidism can &e caused &y all of the following e8cept! ". ravesI disease. $. 9lummerIs disease. C. Struma ovarii. '. BashimotoIs disease. E. Medullary carcinoma of the thyroid. "nswer! E '#SC)SS#*+! Common types of hyperthyroidism include diffuse to8ic goiter 0ravesI disease, named after the 'u&lin physician (o&ert raves who descri&ed it in 1@4; &ut nown since its srcinal description &y 9arry in 17@? and descri&ed &y von $asedow in 1@2A and to8ic adenoma or to8ic multinodular goiter 09lummerIs disease. )ncommon causes include thyroto8icosis factitia, functioning metastatic thyroid carcinoma, tropho&lastic tumors that secrete human chorionic gonadotropin 0having thyroid-stimulating properties, inappropriate secretion of thyrotropin &y pituitary tumors, struma ovarii, iodide-induced hyperfunction, and thyroiditis.
4A. Which of the following is true a&out the use of radioiodine to treat hyperthyroidism> ". #f hyperthyroidism is secondary to radioiodine use, it will occur within years of treatment. $. %here is a maredly increased ris of future thyroid cancer following radioiodine therapy. C. %he ris of leuemia following radioiodine therapy is appro8imately 1A3. '. Mutation a&normalities occur in 1;3 of fetuses in utero following internal treatment of the mother with radioiodine during pregnancy. E. (adioiodine may pass through the placenta and lactating &reast to produce hypothyroidism in a fetus or infant. "nswer! E '#SC)SS#*+! Bypothyroidism secondary to radioiodine therapy increases in freuency with time to @;3 after ; years. %here has &een no demonstration of an increase in malignancies following radioiodine therapy. (adioactive iodine can cross the placenta and lactating &reast to produce hypothyroidism in a fetus or a nursing infant and is, therefore, contraindicated.
41. "rrange the following complications of thyroid surgery 0&ilateral su&total thyroidectomy in decreasing order of incidence in patients with ravesI disease. ".
additional increase in su&seuent years. %he associated mor&idityrelated primarily to damage to the recurrent laryngeal nerves and parathyroid glands is estimated to &e A.;3 to 4.A3.
4. %he most common cause of goitrous hypothyroidism in adults is! ". ravesI disease. $. (iedelIs thyroiditis. C. BashimotoIs disease. '. de QuervainIs thyroiditis. "nswer! C '#SC)SS#*+! BashimotoIs disease was first descri&ed in Napan &y Baaru Bashimoto in 151 and is the &est-nown of the immunologic thyroid diseases. #t is the most common cause of goitrous hypothyroidism in adults and of sporadic goiter in children. %he incidence is A.4 to 1.; cases per 1AAA population per year and it is 1A to 1; times more common in women than in men, with the highest incidence in the group aged 4A to ;A years.
44. %herapy for BashimotoIs disease includes! ". (adioiodine. $. "ntithyroid medications. C. Su&total thyroidectomy. '. +one of the a&ove. "nswer! ' '#SC)SS#*+! %here is no specific treatment for BashimotoIs disease. 9atients are usually followed medically, and replacement therapy with % 2 is &egun in patients with hypothyroidism that is symptomatic or associated with a goiter that is causing pressure symptoms. Early initiation of thyroid hormone therapy has &een recommended &y many to prevent further thyroid
enlargement and reduce the ris of my8edema, especially in postpartum patients. Surgical reduction of goiter should &e performed if severe pressure symptoms that have not responded to corticosteroid therapy are present. %his usually consists of su&total thyroidectomy. $iopsy to rule out malignancy in nodules suspicious for thyroid carcinoma 0usually papillary or lymphoma is indicated. #f carcinoma is suspected, lo&ectomy should &e performed, and if froen section demonstrates carcinoma, su&total or total thyroidectomy should &e performed.
42. #ndications for surgical thyroidectomy for ravesO disease include which of the following> a. *cular involvement &. Symptomatic large goiter c. Women of child&earing age d. Concomitant thyroid nodule e. "ll of the a&ove "nswer! &, c, d "ntithyroid drugs are the initial therapy in most patients with ravesO disease, either as a definitive therapy or in preparation for 141# therapy or surgical a&lation. $ecause of the high failure rate of long-term treatment with thionamides, the use of these drugs as definitive treatment has decreased. 'raw&acs include the important A.;3 incidence of agranulocytosis and a recurrence rate as high as 243 during the first year when the drug is stopped. /ive years after treatment only ;3 of patients remain in remission. )nlie other definitive treatments, hypothyroidism does not occur as a result of thionamide treatment if an appropriate dosage is used. 141# has &een used as definitive treatment for patients with ravesO disease for many years with predicta&le and long-lasting good results in most patients. #t has few, if any, serious side effects. #t is a&lative to the thyroid gland and hypothyroidism is a
nearly inevita&le result of effective therapy, although it may tae years to &ecome clinically apparent. "&out 7A3 of patients treated with 141# are hypothyroid within 1A years of treatment. %he ris of recurrence of hyperthyroidism after an initial response is less than ;3. Most adult patients in the )nited States are treated with 141# as definitive treatment for ravesO disease. E8ceptions are women in the child&earing years where a su&seuent fetus would &e affected, patients with concomitant thyroid nodules where carcinoma is a concern, those with e8tremely large glands and, increasingly, those who are opposed to 141# therapy. %hyroidectomy is an important alternative in selected patients with ravesO disease. "lthough controversial in the past, it now appears that ocular involvement does not respond more favora&ly to thyroidectomy than to 141# a&lation.
4;. Which of the following statements regarding anatomic relationships of the thyroid gland are true> a. %he middle thyroid artery is intimately related to the superior laryngeal nerve &. %he superior thyroid artery is usually the first &ranch of the e8ternal carotid artery c. %hyroidea ima arteries are found in appro8imately A3 of individuals d. %he parathyroid glands may lie within the pretracheal fascia "nswer! &, d %he thyroid gland is a vascular organ supplied &y four main arteries! two superior and two inferior. %he superior thyroid artery usually arises as the first &ranch of the e8ternal carotid artery :ust a&ove the &ifurcation of the common carotid artery. %he superior thyroid artery descends medially on the surface of the inferior pharyngeal constrictor muscle to divide into an anterior and posterior &ranch at the ape8 of the thyroid lo&e on its anteromedial surface. #ts relation to the e8ternal &ranch of the superior laryngeal nerve is
important during thyroid lo&ectomy. %he inferior thyroid arteries usually arise from the thyrocervical truns and ascend &ehind the carotid sheath &efore passing downward and medial to enter the thyroid gland at its middle portion. %here are no arteries directly entering the lower poles from &elow with the e8ception of a thryoidea ima artery that may replace an a&sent inferior artery. %hyroidea ima arteries arise from either the innominate artery or aorta in 13 to 23 of individuals, entering the lower surface of the isthmus after coursing on the trachea. %he pretracheal fascia is referred to as the thyroid sheath and it varies in consistency and completeness among individuals. 9osteromedially, it is usually condensed and firmly attaches the thyroid gland to the upper two or three tracheal rings and the cricoid cartilage. %he superior parathyroid gland may lie &etween the sheath and the thyroid capsule, within the sheath, posterior to it in a potentially open plane, or occasionally anterior to the sheath. %he inferior parathyroid gland liewise may &e within the sheath, particularly when the gland is adherent to the lower pole of the thyroid.
4?. (adioactive iodine is effective treatment for metastatic lung disease for which of the following thyroid neoplasms> a. BPrthle cell carcinoma &. 9apillary carcinoma c. /ollicular carcinoma d. Medullary carcinoma e. "naplastic carcinoma "nswer! &, c (adioactive iodine is used only in patients who have differentiated thyroid carcinomas. #t is of no value in the treatment and follow-up of patients with BPrthle cell, medullary or anaplastic carcinomas. Most papillary carcinomas are capa&le of taing up radioactive iodine. Most papillary carcinomas in
patients under ;A-years of age do so, providing that the patient has had a total thyroidectomy and there is no normal thyroid tissue to compete for the 141#. "&out A3 of all papillary carcinomas do not trap sufficient iodine for imaging or therapy. %hese are usually patients with papillary carcinoma variants! a tall cell variant of papillary carcinoma, insular carcinoma, or clear cell carcinoma. +early all metastatic follicular carcinomas retain the a&ility to trap 141# sufficiently for imaging and for therapy. Even well-differentiated papillary and follicular carcinoma cannot compete successfully for 141# with normal thyroid tissue and unless this has &een removed or su&seuently a&lated with an initial dose of 141#, many metastases cannot &e detected or treated.
47. %he types of thyroiditis that can cause a&normalities of surgical significance are which of the following> a. Chronic lymphocytic thyroiditis 0Bashimoto disease &. (iedel struma c. "cute 0viral thyroiditis d. ranulomatous 0su´ thyroiditis "nswer! a, &, d %here are three types of thyroiditis that can cause thyroid a&normalities of surgical significance. %he most common is chronic lymphocytic 0Bashimoto thyroiditis, an autoimmune disease that can occur in any age group. *ccasionally, Bashimoto disease causes unilateral thyroid enlargement that simulates malignancy. %he rarest form of thyroiditis is (iedel struma which can mimic a diffuse thyroid carcinoma &ecause of the fi&rotic infiltrative process that results. Bashimoto thyroiditis is associated with reduced functional capacity of the thyroid which increases %SB secretion, and a goiter develops. $ecause of the associated fi&rosis, a nodular goiter or neoplasm is suggested. %hyroidectomy may &e indicated for treatment of a solitary
nodule, particularly if it is cold, suspicious, definitely malignant or solid, and fine needle aspirate is indeterminate. ranulomatous, 'eQuervain, and su´ thyroiditis are terms that refer to a disease that usually occurs in young women within wees of an upper respiratory or other viral infection. %he disease is usually self-limited, &ut may persist for several months longer. #n unusual patients, the disease may &e confined to one lo&e and result in a firm, slightly tender mass suggesting carcinoma.
4@. %he principal &lood supply to the parathyroid glands is which of the following> a. Superior thyroid arteries &. #nferior thyroid arteries c. %hyroidea ima arteries d. 9arathyroid arterial &ranches directly from the e8ternal carotid artery e. Bighly varia&le "nswer! &
%he principal &lood supply to &oth parathyroid glands is the inferior thyroid artery. 9arathyroid glands invaria&ly have a single end artery supplying them, and if the main trun of the inferior thyroid artery is ligated during thyroidectomy, there is no collateral &lood supply to maintain their via&ility. #t is prefera&le to divide only the &ranch of the inferior thyroid artery medial to those that supply either of the parathyroid glands. %his reuires individual clamping of smaller vessels under the thyroid sheath as these vessels penetrate into the thyroid capsule.
45. Which of the following statements regarding papillary thyroid carcinoma are true> a. Seventy to @A3 of new cases of thyroid carcinoma in the )nited States are of the papillary type &. %otal ipsilateral lo&ectomy and isthmus resection are adeuate therapy for minimal thyroid carcinoma c. Microscopic evidence of multicentric disease is present in 7A3 to @A3 of cases d. +early all patients less than 1; years of age have metastatic disease in local lymph nodes "nswer! a, &, c, d Seventy to @A3 of the 11,AAA new patients with thyroid carcinoma diagnosed annually in the )nited States have papillary carcinoma. 9apillary carcinomas of the thyroid include minimal thyroid carcinoma, intrathyroidal, and e8trathyroidal 0invasion through the true thyroid capsule disease. Minimal thyroid carcinoma refers to those papillary carcinomas that are less than 1 cm
in diameter and not associated with any clinically apparent lymph node metastases. #n contrast to clinically significant papillary carcinomas, these are common and are found in 3 to 143 of adult thyroid glands serially sectioned after autopsy studies of individuals who have died from other causes. /or tumors &etween A.; and 1 cm, a total lo&ectomy and isthmus resection are satisfactory treatment. Most clinically significant papillary carcinomas are 1 to 2 cm in diameter and are contained within the thyroid capsule. Multicentricity is relatively common and can &e found on gross sectioning of the thyroid gland in A3 to 4A3 of cases. /urthermore, after serial sectioning of the entire thyroid gland in patients with papillary carcinoma, microscopic foci are found in 7A3 to @A3.
2A. " 4A-year-old female presents for evaluation of a palpa&le thyroid nodule. %echnetium-55m 055m%c scan demonstrates a single cold nodule. %he differential diagnosis includes which of the following> a. Carcinoma &. " nonfunctioning adenoma c. " thyroid cyst d. " colloid nodule e. "n autonomous nodule "nswer! a, &, c, d
(adioisotope scanning measures the functional activity of the thyroid gland and maps its correlation with physical findings. /or routine scanning, 141# scanning has &een replaced &y either 14# or 55m%c. $ecause of the lower radiation e8posure, cost and easy use, 55m%c is preferentially used. %he differential diagnosis of a solitary nonfunctioning nodule includes carcinoma, colloid nodule, nonfunctioning adenoma, and cyst. %he prevalence of carcinoma ranges from ;3 to A3 in cold nodules and such lesions reuire further evaluation. #f the scan detects other nonfunctioning areas in addition to the palpa&le nodule, the gland is at low ris for carcinoma &ecause most patients with this finding have a multinodular goiter. " solitary, discrete area of increased activity is more often found in a young patient with an otherwise normal thyroid gland. Multiple hot spots are typically found in an older patient with a multinodular goiter. " functioning solitary nodule that is independent of %SB is considered an autonomous nodule and can &e the cause of hyperthyroidism. #t is hot on scintigraphic scan. %he presence of a cold nodule is insufficient information to determine a treatment plan. "lthough nearly all carcinomas are cold, most cold nodules are &enign. /ine needle aspiration cytology is considered the most relia&le means of evaluation for the diagnosis of thyroid nodules that are nonfunctional or hypofunctional &y nuclide scan.
21. Which of the following pharmacologic agents can &e used in the treatment of thyroto8icosis to &loc the production of thyroid hormone> a. 9ropylthiouracil &. 9ropranolol c. Methimaole d. Car&imaole e. #odine "nswer! a, c, d, e
" num&er of su&stances interfere with normal production of thyroid hormone &y &locing one of the relevant enymatic steps. #odine was the first effective drug to &e used in the treatment of thyroto8icosis. #t can &loc the organification and coupling steps in thyroid hormone synthesis as well as prevent the release of thyroid hormone. /urthermore, iodine in large doses pro&a&ly inhi&its the a&ility of %SB to stimulate cyclic "M9 release at the follicular cell mem&rane. Commonly used antithyroid drugs are propylthiouracil 09%), methimaole 0%apaole and car&imaole. Car&imaole is widely used in reat $ritain, only 9%) and methimaole are commonly used in the )nited States. 9%) interferes with the incorporation of iodine into the tyrosine residues of thyroglo&ulin, thus preventing o8idation of iodide to iodine. #t also inhi&its the peripheral conversion of %2 to %4. "lthough &oth 9%) and methimaole are thionamides, methimaole does not have this peripheral effect, maing 9%) the preferred drug for patients with thyroid storm. "&out 43 of patients taing 9%) demonstrate at least one side effect during the first 4 months of therapy whereas the prevalence with methimaole is a&out 73. %hese range from minor sin rashes to agranulocytosis that can &e irreversi&le. &-adrenergic antagonists have &een used in the treatment of hyperthyrodism. 9ropranolol is the most widely used of these drugs. Bowever, &-&locade does not alter thyroid function per se. (ather, its effect is to provide symptomatic relief of hyperthyroidism &ecause of interference with the action of thyroid hormones at the cellular level.
2. " 2;-year-old woman has a solitary, nonfunctioning thyroid nodule and fine needle cytology is nondiagnostic. Which of the following is the initial surgical procedure of choice> a. %otal e8tracapsular thyroidectomy &. Su&total thyroid lo&ectomy and resection of the isthmus
c. %otal e8tracapsular thyroid lo&ectomy, resection of the isthmus, and modified unilateral nec dissection d. %otal e8tracapsular thyroid lo&ectomy and resection of the isthmus "nswer! d %otal e8tracapsular thyroid lo&ectomy and isthmus resection is the procedure of choice when a decision has &een made to surgically remove a thyroid nodule. %he entire lo&e with the isthmus is su&mitted for froen-section pathologic e8amination if fine needle aspirate has not already resulted in a definitive diagnosis of carcinoma. #n performing total lo&ectomy, &oth parathyroid glands are carefully preserved with their &lood supply. %his is done in the event that total thyroidectomy is necessary if either the froen or permanent histologic sections confirm the presence of thyroid carcinoma. %otal lo&ectomy offers the &est opportunity for accurate histologic diagnosis and is associated with the lowest incidence of complications when the need for reoperation is considered. #n one e8perience, @AA consecutive cases of total unilateral lo&ectomy were performed for &enign or malignant nodules suspected of cancer, and no permanent recurrent laryngeal nerve palsies occurred. 9rimary total lo&ectomy is safer than a partial lo&ectomy followed &y resection of the residual lo&e after a delayed diagnosis of malignancy. (eoperation to complete a lo&ectomy is associated with a greater ris to &oth recurrent laryngeal nerve and the parathyroids on the ipsilateral side. "lthough there is controversy as to whether a total lo&ectomy and isthmus resection or a total thyroidectomy is the &est definitive operation for unilateral papillary carcinoma, a su&total lo&ectomy is universally considered an inadeuate operation. " definitive cancer operation can &e accomplished with one procedure in @A3 of the cases when a silled thyroid pathologist is availa&le for froen-section interpretation.
24. Which of the following statements regarding fine needle aspiration cytology of a thyroid nodule are true>
a. #t differentiates neoplastic and nonneoplastic nodules in most cases &. #t does not allow differentiation of papillary, medullary and anaplastic carcinoma c. #t cannot differentiate malignant and &enign follicular or BPrthle cell neoplasms d. #t is not recommended when a patient has a history of head and nec radiation "nswer! a, c, d When interpreted &y a silled cytologist, fine needle aspiration is highly accurate and is considered the preferred method of selecting patients with thyroid nodules for surgery. +early @A3 of patients with thyroid nodules were spared surgical e8ploration as a result of such studies in one report. $ecause of the ris of false-negative diagnoses 01A3, advocates of this techniue emphasie the importance of clinical :udgment in addition to the cytologic study in selecting operative candidates. #n most cases, fine needle aspiration cytology ena&les the pathologist to distinguish nonneoplastic from neoplastic nodules and to identify the type of malignant tumor. 9apillary, medullary, and anaplastic carcinoma all have a typical cytologic appearance. Cytologic studies cannot differentiate malignant from &enign follicular or BPrthle cell neoplasms. #n this case, a definitive diagnosis depends on histologic e8amination of the entire e8cised tumor. /ine needle aspiration has dramatically reduced the num&er of diagnostic surgical operations for &enign lesions in centers where it is used e8tensively. #n patients with thyroid nodules and a history of previous head and nec radiation, operation is generally recommended regardless of cytologic findings. #n these patients, &oth &enign and malignant lesions may develop and the chances of sampling error are considera&le.
22. Byperthyroidism results from all of the conditions noted &elow. *f the
following which commonly reuire surgical management> a. ravesO disease &. Struma ovarii c. /unctioning metastatic thyroid carcinoma d. %o8ic diffuse goiter e. Single to8ic thyroid nodule "nswer! a, d, e Byperthyroidism is associated with clinical manifestations related to an e8cess of thyroid hormone. %here are three causes of primary concern to the surgeon. ravesO disease, or to8ic diffuse goiter, is most common, accounting for more than @A3 of all patients with hyperthyroidism. %he other two relevant causes of hyperthyroidism are to8ic nodular goiter and a single to8ic nodule. Common causes of hyperthyroidism that rarely reuire surgery are postpartum thyroiditis, iodine-induced hyperthyroidism, self-administered or iatrogenic hyperthyroidism, struma ovarii, functioning metastatic carcinoma and several rare forms of thyroiditis.
2;. Which of the following statements regarding medullary carcinoma of the thyroid are true> a. "ppro8imately 7;3 of all cases are hereditary &. %he overall 1A-year survival rate is less than 1A3 c. Medullary carcinoma of the thyroid is associated with &oth multiple endocrine neoplasia ##a 0ME+ ##a and multiple endocrine neoplasia ##& 0ME+ ##& syndromes d. 9rophylactic total thyroidectomy is recommended for ME+ ##a and ME+ ##& patients after the age of 1A years "nswer! c
Medullary carcinoma of the thyroid 0MC% accounts for a&out 73 of all malignant tumors of the thyroid. #t is familial in A3 to 4A3 of all cases and its secretion of a &iologic marer 0calcitonin allows detection of its presence with the tumor is too small to palpate. MC% appears in three clinical settings. %he first is a sporadic tumor, usually in patients 4A years or older. Second, MC% occurs as a component of the ME+ ##a syndrome with or without adrenal medullary disease 0pheochromocytoma or hyperparathyroidism. " family history of thyroid carcinoma with or without pheochromocytoma is invaria&ly present. MC% in the ME+ ##a syndrome is always &ilateral and multicentric and arises from C-cell hyperplasia. MC% usually does not develop &efore age 1 and is almost always clinically apparent &efore age 4A.
2?. Which of the following statements regarding thyroid physiology are true>
a. +ormally a&out A3 of %4 is secreted directly from the thyroid gland &. %he thyroid gland is the only endogenous source of %2 c. E8cess thyroid hormone results in an increase in the num&er of "%9dependent sodium pumps on the cell mem&rane d. %he ma:ority of thyroid hormone in circulating plasma is &ound to al&umin, thus limiting the availa&ility of the meta&olically active form "nswer! a, &, c %he thyroid is the only endogenous source of %2, whereas most %4 is produced &y the peripheral conversion of %2. %his taes place in the liver, muscle, idney and anterior pituitary. )nder normal circumstances, only a&out A3 of %4 is secreted directly from the thyroid gland. #n some thyroid diseases 0e.g., ravesO disease and to8ic nodular goiter, the proportion of %4 secreted directly &y the thyroid may &e maredly increased. *nce thyroid hormones are released into the circulation, they are &ound to thyroid-&inding glo&ulin 0@;3, al&umin 01A3 and transthyretin 0preal&umin. %hese &inding proteins allow the thyroid hormones to remain solu&le in plasma, contri&uting to systemic distri&ution to various target-cell populations. " limited amount of thyroid hormones circulates freely in the plasma in meta&olically active form 0free %2, free %4. "t the cell mem&rane, an e8cess of thyroid hormone results in an increased num&er of "%9-dependent sodium pumps, thus increasing resting energy e8penditure and o8ygen consumption. %hyroid hormone also facilitates the transport of glucose and amino acids across the cell mem&rane. #n addition, %4-induced mitochondrial o8idation of su&strate results in increased "%9 production.
27. %he definitive treatment of choice for to8ic multinodular goiter is> a. %otal thyroidectomy
&. $ilateral su&total thyroidectomy c. )nilateral total lo&ectomy on the side of dominant disease d. 141# treatment "nswer! & Byperthyroidism in the patient with a multinodular goiter usually develops in women after age ;A &ut is seen occasionally in younger patients. Most patients have had a nonto8ic nodular goiter for many years. 9referred treatment for most patients with to8ic multinodular goiters is thyroidectomy after adeuate preparation renders the patient euthyroid. 141# may &e an alternative in selected poor-ris patients with goiters that are not causing airway compression. "lthough 141# can &e used to treat the hyperthyroidism, larger and often repeated doses of 141# may &e reuired. 141# does not significantly reduce the goiter sie and may, &ecause of radiation-induced thyroiditis, cause acute enlargement. %his may &e haardous in the patient with some degree of pree8isting airway compression. "ny airway symptoms, particularly in patients with su&sternal goiters, should &e considered strong contraindications to the use of 141#. Standard surgical treatment of to8ic nodular goiter has consisted of &ilateral su&total thyroidectomy. (emnant sie is not as important as the e8cision of all autonomous nodules. $ecause thyroid replacement or suppression is used routinely to prevent recurrence of goiter when a su&total resection is done, the ris of hypothyroidism is not a consideration in determining remnant sie. "lternative procedures are total lo&ectomy with isthmus resection and contralateral su&total lo&ectomy, or total thyroidectomy. %he latter is not demonstra&ly superior and may have more technical complications.
2@. " ;A-year-old male has undergone an ipsilateral thyroid lo&ectomy and isthmus resection for what appeared on froen section to &e a &enign nodular lesion .A cm in diameter. Seventy-two hours later the final pathology returns and the diagnosis is a high-grade angioinvasive follicular carcinoma. What do
you recommend> a. 55m%c &one scan to rule out occult &one metastases &. #psilateral radical nec dissection c. %otal thyroidectomy d. *&servation with seuential 141# scans every 4 months "nswer! c /ollicular carcinoma accounts for a&out 1A3 of all new carcinomas of the thyroid. Most patients are those with minimal invasion of the capsule or vessels within the neoplasms. Such tumors are seldom diagnosed definitively &y either needle aspiration cytology or &y froen-section diagnosis at the time of lo&ectomy. Most freuently, the diagnosis is made after the study of permanent sections. Microinvasive encapsulated follicular carcinomas are rarely associated with metastatic lymph nodes and distant metastases involving &one are also rare at the time of diagnosis. "ngioinvasive follicular carcinomas are usually large and freuently show venous invasion of perithyroidal and lateral nec veins at the time of diagnosis. %hey may have already metastasied to different sites, most freuently the &one. %hese tumors are often diagnosed at the time of operation &ecause of these characteristics. Most patients younger than 2A do well, &ut patients older than ;A years have a guarded prognosis. /ollicular carcinomas of the thyroid are treated &y total thyroidectomy.
rule out occult &one metastases. 9atients with large or high-grade angioinvasive lesions reuire total thyroidectomy. 49. In 1990 a National Institutes of Health Consensus Dev pment Conference reviewed the available evidence regarding the management of asmptomatic primar hperparathroidism. !he panel concluded that surgical intervention was indicated for which of the following indications"
a. #ge less than $0 ears of age b. %educed creatinine clearance
c. 9resence of idney stone0s 0as detected &y a&dominal radiograph d. Su&stantial reduced &one mass as determined &y direct measurement e. Maredly elevated 2-hour urinary calcium e8cretion "nswer! a, &, c, d, e "ll of the indications listed a&ove are considered indications for operative treatment of asymptomatic patients with primary hyperparathyroidism. %heir conclusions regarding operative indications are summaried in %a&le ;7-@. %he +#B Consensus 'evelopment Conference mandated close 0every ? months follow-up for patients with nown primary hyperparathyroidism not treated &y operation. #n addition, surgery was agreed upon for those patients in whom medical surveillance was neither desira&le nor suita&le, such as when the patient reuests surgery, consistent follow-up is unliely, coe8istent illness complicates management, or if the patient is young 0 ;A year of age. #n one recent study of a group of 12 asymptomatic patients followed without operation, after 1A years, more than A3 of the patients had reuired surgery for an increase in serum calcium to greater than 11 mg=d< or for specific complications attri&uta&le to the disease. "nother A3 were lost to or declined follow-up. %he remainder either died of unrelated causes or had persistent asymptomatic disease. %his remains an area of considera&le
controversy. %he &est availa&le recommendations are derived from this *cto&er 155A +#B Consensus 'evelopment Conference. ;A. Which of the following statements regarding medullary carcinoma of the thyroid are true> a. $ilateral medullary carcinoma of the thyroid occurs in every patient with multiple endocrine neoplasia 1, a or & &. Medullary carcinoma of the thyroid accounts for appro8imately one-third of all thyroid malignancies c. A3 of medullary carcinoma of the thyroid cases are familial d. 9rovocative testing with pentagastrin and calcium infusion for family mem&ers at ris for medullary carcinoma of the thyroid is diminished in importance &y the recent development of specific genetic testing "nswer! a, c, d Medullary thyroid carcinoma accounts for a&out 1A3 of all thyroid malignancies, and A3 of cases occur in the familial setting of ME+ a, ME+ $, or familial nonME+ medullary thyroid carcinoma. #t is usually the first tumor that develops in these patients and typically occurs in the second or third decade of life. %umors are virtually always &ilateral and develop in multiple areas of the middle and upper portions of the thyroid lo&e. 'etection has historically &een &ased on ela&oration of calcitonin, particularly in response to provocative testing &y the potent secretagogues calcium and pentagastrin. 9atients with medullary carcinoma of the thyroid have striing increases in plasma calcitonin levels after provocative testing, which allows them to &e readily identified. $y employing provocative testing in indred mem&ers at ris for disease, medullary carcinoma of the thyroid was diagnosed at a preclinical stage, and a greater percentage of these patients were cured &y surgical therapy. With genetic testing now availa&le, early treatment of medullary thyroid cancer should &e possi&le for all affected people, to hopefully enhance the num&er of people cured of this cancer. %he ME+ 1, a and & syndromes are inherited in an autosomal dominant fashion with complete penetrance &ut varia&le phenotype. $ilateral medullary carcinoma of the thyroid occurs in every affected patient. ;1. While awaiting surgery on a BM* waiting list, a ;A-year-old female with primary hyperparathyroidism is
admitted to the hospital with oliguria, confusion, nausea and vomiting, muscle weaness and a serum calcium of 14.; mg=d<. *f the treatment options &elow, which one is the most appropriate> a. "dminister 1 gm of hydrocortisone S%"% &. $egin an #G E'%" 0chelating agent infusion S%"% c. "dminister #G Mithramycin and calcitonin concurrently and proceed to #C) for cardiac monitoring d. $egin a normal saline infusion at R maintenance volume followed &y 1mg=g furosemide #G e. +one of the a&ove "nswer! d 9atients with mared hypercalcemia or severe symptoms should &e admitted to the hospital for careful o&servation and monitoring. %he mainstay of therapy is intravenous hydration, prefera&ly with normal saline in sufficient uantities to maintain the urine output a&ove 1AA m<=h. %hese patients are often dehydrated &efore therapy, and fluid can &e administered intravenously at a rate of AA m<=h. Caution must &e e8ercised in older patients who might have marginal cardiac reserve. %he diuretic furosemide also increases e8cretion of sodium and calcium &ut should not &e employed until the patient is well hydrated. Saline diuresis is usually effective when the hypercalcemia results from hyperparathyroidism or from a &enign cause. #n contrast, the hypercalcemia of malignancy may produce severe symptoms associated with e8tremely high serum calcium levels that are difficult to control. #n this setting, a variety of other measures may &e considered 0see %a&le ;7-4. Some of the agents used to treat hypercalcemia have significant to8icity and reuire close monitoring. Calcitonin is a fairly wea hypocalcemic agent, &ut it acts rapidly and is relatively less to8ic. lucocorticoids may &e particularly efficacious in patients with sarcoidosis and other granulomatous diseases. Mithramycin has proved useful in patients with hypercalcemia of malignancy, &ut it has a su&stantial cumulative to8icity 0throm&ocytopenia, hepatoto8icity, and nephroto8icity. #ntravenous phosphates and chelating agents have largely &een a&andoned &ecause of their severe to8icity. ;. Which of the following conditions are associated with hypercalcemia> a. Byperthyroidism &. %hiaide diuretics c. %erminal
ileal resection d. $reast cancer e. "ll of the a&ove "nswer! a, &, d Multiple causes of hypercalcemia include the following! Malignancy Gitamin " or ' into8ication %hiaide diuretics Byperthyroidism Mil-alali syndrome Sarcoidosis and other granulomatous diseases /amilial hypocalciuric hypercalcemia #mmo&iliation 9agetOs disease a. 9roceed to *( for e8ploration of the operative site &. "dminister ; ml of 1A3 calcium gluconate intravenously c. *&tain a serum magnesium measurement and administer intravenous magnesium chloride S%"% d. *&tain a C% scan of the head to evaluate the possi&ility of &rain metastases "nswer! & 9ostoperative hypoparathyroidism commonly develops after total thyroidectomy for malignancy. Most patients undergoing operation on the thyroid e8perience some alteration in serum calcium. %he hypocalcemia is usually transient and is not treated unless significant symptoms develop. %he plasma calcium
usually reaches its nadir at 2@ to 7 hours after surgery and then slowly returns to normal over to 4 days. /or these reasons, careful postoperative monitoring of serum calcium levels is essential. /or acute symptomatic hypocalcemia, calcium should &e administered intravenously. )sually A to 4A m< of 1A3 calcium gluconate is infused over a 1; to A minute period and then ;A to 1AA m< are administered over the ne8t 1 hours in adults. Calcium gluconate is less irritating to the veins than calcium chloride, and the calcium release is slower without the ris of overcorrection. Serum magnesium should always &e measured and hypomagnesemia should &e corrected if present. %his is not the first priority for this patient. Symptoms should never &e allowed to progress to the point demonstrated in this patient. 9ostoperative routines include careful monitoring of the serum calcium until sta&le. %here is no evidence that this patient has a postoperative surgical pro&lem such as a cervical hematoma. a. 9rimary hyperparathyroidism &. Secondary hyperparathyroidism c. %ertiary hyperparathyroidism d. Ectopic hyperparathyroidism "nswer! a 9rimary hyperparathyroidism develops spontaneously without apparent cause, &ut possi&ly in response to e8ogenous stimuli. When the normal control of serum calcium is distur&ed and there is increased autonomous production of 9%B, the state is referred to as primary hyperparathyroidism. #n contrast, secondary hyperparathyroidism occurs when there is a defect in mineral homeostasis that leads to a compensatory increase in parathyroid function. %his occurs most commonly in response to renal disease, &ut may also develop as a conseuence of the hypocalcemia
associated with some diseases of the gastrointestinal tract, &one or other endocrine organs. *ccasionally, with prolonged secondary stimulation, the hyperfunctioning glands are no longer physiologically responsive to an increased ionied calcium. %his rare, relatively autonomous state is referred to as tertiary hyperparathyroidism and develops most commonly after renal transplantation when the defect in calcium homeostatis is corrected. %he numerical values for calcium and 9%B here are consistent with primary hyperparathyroidism. (elation &etween serum immunoreactive parathyroid hormone 0i9%B and serum calcium in patients with hypoparathyroidism, pseudohypoparathyroidism, ectopic hyperparathyroidism, and primary, secondary, and tertiary hyperparathyroidism. 91M, guinea pig antiserum 1M. 0"fter Clar *B, Way a. (ecurrent postoperative hypercalcemia occurs in appro8imately A3 of patients with this clinical scenario &.
correct initial diagnosis and review of the srcinal operative and pathology reports are essential. #t is generally agreed that localiation studies do have a place in the management of recurrent disease. +oninvasive methods are employed first, and if these are unsuccessful in identifying the diseased gland, selective angiography and venous sampling for 9%B are employed. Selective angiography appears to &e the most accurate techniue, successfully localiing ;A3 to @A3 of parathyroid glands that cannot &e detected &y any other modality. Surgical ree8ploration can &e difficult. enerally the nec is e8plored first after which the mediastinum is e8amined if this is unproductive. Surgical ree8ploration is successful in e8perienced hands in ?A3 to @A3 of cases. %here is, however, an increased incidence of complications. )nilateral recurrent nerve in:ury occurs in ;3 to 1A3 of patients and permanent hypoparathyroidism occurs in 1A3 to A3 of patients postoperatively. ;?. Which of the following statements regarding calcium and phosphate meta&olism are true> a. 9arathyroid hormone e8cess produces a net increase in daily urinary calcium e8cretion &. Calcitonin is essential for the normal control of calcium meta&olism in adult humans c. 9arathyroid hormone is the single most important regulator of calcium and phosphate meta&olism in humans d. 1,; dihydro8yvitamin '4 0calcitriol is the active form of vitamin ' in humans "nswer! a, c, d %he primary hormonal regulators of calcium and phosphate meta&olism are parathyroid hormone 09%B, vitamin ' and calcitonin. 9arathyroid hormone appears to &e the single most important hormonal regulator of calcium and phosphate meta&olism in humans. #t has direct effects on the seleton and idney and indirect effects on the intestine, mediated through vitamin '. Sustained elevations of 9%B stimulate osteoclasts and inhi&it osteo&lasts leading to a&sorption of calcium from &one. #n the idney, 9%B produces an increase in rea&sorption at any given concentration of e8tracellular fluid calcium, although e8cess secretion, &ecause of the hypercalcemia, results in a net increase in daily urinary calcium e8cretion. Gitamin '4, or cholecalciferol, is
produced normally &y the action of sunlight on 7-dehydrocholesterol in the sin. #t is then hydro8ylated in the liver 0; position and idney 01 position to form the active 1,; dihydro8yvitamin '4 0calcitriol. %his is the active form of Gitamin ' in humans. Calcitonin is a 4-amino acid protein produced &y the parafollicular C cells of the thyroid. %otal thyroidectomy, with removal of all the C cells, is well tolerated, and it has &een concluded that calcitonin is not essential for the normal control of calcium meta&olism in adult humans. Calcitonin does inhi&it &one resorption and can produce hypocalcemia in e8perimental animals. #t also increases urinary calcium and phosphate e8cretion. ;7. Multiple Endocrine +eoplasia 0ME+ & is characteried &y which of the following findings> a. Medullary carcinoma of the thyroid, pheochromocytoma, mucosal neuromas, and a distinctive marfanoid ha&itus &. 9arathyroid hyperplasia, pancreatic islet cell tumors, and pituitary adenomas c. Medullary carcinoma of the thyroid, pheochromocytoma, and parathyroid hyperplasia d. 9arathyroid carcinoma, pheochromocytoma and chronic pancreatitis "nswer! a %he multiple endocrine neoplasias are familial disorders typically characteried &y predisposition to the development of tumors of multiple endocrine organs. %hese disorders are all inherited in an autosomal dominant fashion, and the tumors tend to &e multicentric. %he tumors may &e &enign or malignant and may occur metachronously or synchronously. ME+ 1 is characteried &y the concurrence of parathyroid hyperplasia, pancreatic islet cell tumors, and pituitary adenomas. ME+ a consists of medullary carcinoma of the thyroid, pheochromocytoma, and parathyroid hyperplasia. ME+ & includes medullary carcinoma of the thyroid, pheochromocytoma, mucosal neuromas, and a distinctive marfanoid ha&itus. %ogether, these syndromes encompass much of the spectrum of endocrine neoplasia. ;@. Which of the following signs=symptoms are pathognomonic of hyperparathyroidism> a. 9athologic fractures of the metacarpals &. Calcium o8alate nephrolithiasis c. Bypercalcemia causing mental status changes d. "trophy of %ype ## muscle fi&ers e. *steitis fi&rosa
cystica "nswer! e Manifestations of hyperparathyroidism are protean, &ut generally nonspecific and may &e difficult to elicit in the history. %he earliest complaints are often vague and include muscle weaness, anore8ia, nausea, constipation, polyuria, and polydipsia. %hese nonspecific symptoms may or may not cause the patient to see medical attention. Symptomatic patients generally have evidence of chronic disease involving the idney or the seleton. (enal complications develop &ecause the hypercalcemia leads to increased urinary calcium e8cretion and 9%B increases the e8cretion of phosphate. %hese events predispose to stone formation. +ephrolithiasis develops in a&out 4A3 of patients. +ephrocalcinosis occurs in ;3 to 1A3 of patients. %hese are &oth nonspecific for hyperparathyroidism. 9arathyroid &one disease in its most classic and severe form, osteitis fi&rosa cystica, is seldom seen. Bowever, ;3 to 1;3 of patients present with significant symptoms of seletal disease. *nly the seletal disease is pathognomonic. $one changes include su&periosteal resorption of &one on the radial aspect of the middle phalan8 of the second or third finger. %ufting of the distal phalanges, &one cysts of the sull and long &ones, &rownD tumors 0i.e., localied proliferations of osteoclasts, and diffuse demineraliation or granularity are seen as well. "trophy of %ype ## muscle fi&ers, consistent with a neuropathic and not a myopathic cause, has &een demonstrated in patients with hyperthyroidism, &ut this too is nonspecific. ;5. %he causes of Cushing syndrome may include which of the following> a. 9osterior pituitary adenoma &. "drenal hyperplasia c. Small cell lung carcinoma d. 9heochromocytoma e. "drenal carcinoma "nswer! &, c, e %he varied causes of cortisol e8cess produce clinical features that are collectively called Cushing syndrome. %hese include e8ogenous steroid administration, Cushing disease 0e8cessive "C%B production &y the anterior pituitary gland, usually from an adenoma, ectopic "C%B production 0small cell lung carcinoma, adrenal adenoma or carcinoma, micronodular pigmented hyperplasia, macronodular hyperplasia, and steroid-dependent adrenal hyperplasia.
9heochromocytoma is characteried &y catecholamine rather than cortisol e8cess as it arises from the adrenal medulla rather than the adrenal corte8. ?A. Which of the following are normal systemic effects of glucocorticoids> a. Enhanced proteolysis &. #ncreased gluconeogenesis c. 'iminished lipolysis d. 'ecreased rate of intestinal epithelial replication "nswer! a, &, d %he many systemic effects of glucocorticoids are related to regulation of intermediary meta&olism. #n this regard, perhaps the most important action is the effect of steroids on protein &readown. " direct proteolytic effect of steroids is suggested &y several lines of evidence. lucocorticoids enhance gluconeogenesis &y &oth a direct effect on gluconeogenic hepatic enymes and also &y provision of su&strate for gluconeogenesis &y proteolysis. lucocorticoid influence leads to the accentuation of lipolysis. %he truncal o&esity seen in steroid e8cess is related to the predominance of the lipogenic effect of insulin on truncal adipocytes over the lipolytic effect of glucocorticoids. %he opposite relation may hold for the receptors in fat of the e8tremities and would e8plain the comparatively scant fat in these areas with steroid e8cess. %he most nota&le effect of glucocorticoids in the intestinal tract is a decrease in the rate of mucosal cell replication. #n addition, decreased mucosal and pancreatic prostaglandin synthesis occur. %his may have important implications for the cytoprotective mechanisms in the stomach. ?1. " 1A-year-old child presents with hypertension, tachycardia, nervousness and sweating. %he &est initial diagnostic evaluation is which of the following> a. (adioimmunoassays for norepinephrine and epinephrine in serum &. Magnetic resonance imaging of the adrenal gland c. M#$ 0141#Methaiodo&enylguanidine scintigraphy d. Measurement of catecholamines and their degradation products in a 2-hour urine specimen "nswer! d %he first diagnostic step in determining the functional state of an adrenal gland or lesion is to screen the urine or plasma for secretory products. *nce hypersecretion is demonstrated, the specific type of pathology producing a syndrome must &e determined with the aid of functional tests and relevant
scanning and imaging. %he most efficient and sensitive means of screening in a patient suspected of having a pheochromocytoma, 0as indicated here is measurement of the catecholamines or meta&olic products thereof in the urine. "lthough 2-hour samples can smooth out the possi&le episodic variations in catecholamine secretion, shorter sampling periods can &e useful, especially if corrected for creatinine e8cretion. %iming of the collection is critical in patients who have only episodic hypertension. )rine collection should &e started immediately after a suspected attac of hypertension. /luctuations in plasma catecholamine concentrations are much greater than those in urinary e8cretion, even in normal su&:ects. 9lasma determinations are uite sensitive and specific with radioimmunoassays and B9 a. *n the day of surgery he should receive 1AA mg hydrocortisone #G ?h &. %he postoperative steroid dose should &e halved 1 hours to reduce the ris of infectious complications and improve would healing c. 9rophylactic treatment with a somatostatin analogue will reduce the ris of postoperative pancreatitis d. E8ogenous steroid replacement can &e stopped after 4 months "nswer! a %he postoperative course of management for a patient with pituitary adrenal suppression from e8ogenous steroids involves tapering the e8ogenous steroid doses to maintenance levels after high dose replacement at the time of operation. *ne simple regimen involves
administering 1AA mg of hydrocortisone intravenously every ? hours during the first 2@ hours. Some prefer alternating doses of #M cortisone acetate in the event that intravenous access is lost. 9rovided that no intervening complications arise, the doses can &e halved every 2@ to 7 hours. #n patients who have &een e8posed preoperatively to glucocorticoid e8cess, the maintenance dose may &e as high as 1AA mg=d for several months. $oth high doses and normal maintenance of 4; to ;; mg=d can &e given in the form of oral cortisone acetate as long as relia&le alimentation and a&sorption have &een achieved. %he pituitary-adrenal a8is remains suppressed for ? to 1 months after operation. Complications in the postoperative period include wound infection, pancreatitis, and throm&oem&olism. %here is no data to suggest that the ris of postoperative pancreatitis can &e diminished with somatostatin analogue therapy. ?4. #maging of the adrenal gland is &est achieved with which of the following techniues> a. )ltrasound &. Computed tomography 0C% c. "rteriography d. Scintigraphy with 141#-? &-iodomethyl15-norcholesterol 0+9-;5 e. Scintigraphy with 141#methaiodo&enylguanidine 0M#$ "nswer! & "lthough ultrasonography is the least e8pensive of the imaging procedures, its value is limited &y the relative inaccessi&ility of the adrenal gland and &y the small sie of some adrenal lesions. C% is the techniue most commonly used to e8amine patients in whom adrenal a&normalities are suspected. C% relia&ly detects adrenal tumors greater than 1 cm in diameter. %he sensitivity of C% for tumors that are 1 cm in diameter is a&out @A3 and reaches 1AA3 for tumors that are 4 to 2 cm. "lthough C% is noninvasive and reasona&ly sensitive, it is nonspecific. #t does not distinguish functioning from nonfunctioning tumors, nor &enign from malignant tumors with any degree of relia&ility. M(# has developed a certain usefulness even after retrenchment from early optimistic predictions. M(# is more e8pensive and reuires greater patient cooperation than C%, &ut it has greater versatility &ecause of the use of %#-and %-weighted images. #n some cases, the %-weighted images are capa&le of providing a differential
diagnosis and may distinguish such entities as metastatic or primary carcinoma and pheochromocytoma from adenomas, lipomas, myelolipomas and cysts. #n a sense, M(# is complementary to C% in that the latter can &etter detect the lesion while the former can distinguish one type of lesion from the other. #n addition, M(# is pro&a&ly &etter than C% for distinguishing anatomic relationships and the e8tent of involvement of the surrounding tissues. %wo radiopharmaceuticals have proved useful in imaging the adrenal gland. "drenocortical lesions can &e imaged &y +9-;5 which is taen up as cholesterol in the adrenocortical steroidogenic pathway. %he other agent is M#$, a norepinephrine analogue. #t indicates norepinephrine accumulation in storage vesicles and can detect sympathoadrenal tumors at any site in the &ody. +9-;5 can localie the adrenal corte8 and any functioning tumors. #t can distinguish adrenocortical hyperplasia from functioning adenomas or carcinomas. M#$ is a useful agent in localiing pheochromocytomas throughout the &ody, especially when the tumors are multiple, e8traadrenal, recurrent, or metastatic. "rteriography, venography and selective venous sampling have &ecome less popular as e8perience with other imaging techniues has &ecome greater. 'isadvantages inherent in invasive procedures using intravascular contrast agents are o&vious. "rteriography is specifically dangerous in the study of patients with pheochromocytomas. ?2. " 2;-year-old female is found to have a cm solid nodule in her right adrenal gland at the time of an a&dominal C% scan following an auto accident. With regard to the adrenal lesion, she is asymptomatic and it is found to &e nonfunctional on evaluation. Tou would recommend which of the following> a. E8traperitoneal right adrenalectomy through either a flan of posterior approach &. Suppression with ; mg prednisone 9* od c. /ollowup C% scan in 1 to 4 months d. E8cisional &iopsy via laparaoscopic approach "nswer! c #ndication for operation in the patient with a unilateral functioning adrenal tumor is clear. #n the patient with a nonfunctioning adrenal tumor, the need for surgery is related to the sie of the tumor and its rate of growth. %here is
consensus that a tumor larger than ? cm should &e removed. Some recommend that the accepta&le sie limit &e 4 cm, especially when M(# suggests carcinoma or when the functional studies suggest activity. When nonoperative therapy is elected, the patient should receive an adrenal scan 1, 4, and ? months after the initial scan and yearly thereafter to assess the growth of the lesion. #f the tumor has grown, surgical removal is indicated. ?;. " A-year-old male with a 1A cm left adrenal mass is found to have 1A mg of norepinephrine in a 2-hour urine collection and a plasma 1@ hydro8ycorticosterone level of ;A mg=d<. #nitial reoperative preparation should include which of the following> a. %reatment with spironolactone &. #ntravenous potassium-loading to prevent intraoperative hypoalemia c. %reatment with pheno8y&enamine d. %reatment with la&etalol "nswer! c %his patient has a pheochromocytoma. %he most efficient and sensitive means of screening for pheochromocytoma is measurement of the catecholamines, or meta&olic products thereof, in the urine. %he catecholamines, norepinephrine and epinephrine, are e8creted in amounts under 1AA Ug=d in the normal person. $ecause of some overlap in values, specificity can &e improved &y using a normal range of up to ;A mg=d. %he measurement of plasma 1@-hydro8ycorticosterone level is helpful in evaluating patients with hyperaldosteronism, as it is an intermediate product in its synthesis. %he 1@-hydro8ycorticosterone levels are a&ove 1AA mg=d< in virtually all patients with aldosterone producing adenomas. %he plasma value for this patient is normal. 9erioperative treatment with either spironolactone and potassium replacement is appropriate for patients with hyperaldosteronism, &ut not pheochromocytoma. +onoperative treatment of pheochromocytoma is generally unsatisfactory and entails pharmacologic &locade of the effects of catecholamines. 9heno8y&enamine and praosin are two preferred agents that &loc the a-adrenergic effects of the catecholamines preoperatively with pheochromocytoma. %he use of &adrenergic &locers, such as la&etalol, may &e reuired in those patients with
o&vious &-adrenergic effects, such as resting pulse rates a&ove 1AA &eats=min. $ecause of the potential for wide swings in &lood pressure and other effects of chronic catecholamine secretion, careful preoperative preparation is reuired in patients with pheochromocytoma. #t is customary to institute aadrenergic &locade to 4 wees &efore anticipated surgery. %his has &eneficial effects of controlling &lood pressure and allowing restoration of a decreased &lood volume. #t is the consensus that preoperative preparation in the manner maes the intraoperative management of the patient much more safe. #n patients who reuire &-adrenergic &locade, it is essential to first esta&lish good a-adrenergic &locade. %hese patients are prone to cardiac failure induced &y &-adrenergic &locade &ecause of the cardiomyopathy that may pree8ist. &-"drenergic &locade in the cardiomyopathic patient with failure to first reduce the afterload &y a-adrenergic &locade, can precipitate cardiac failure. ??. Which of the following diagnostic tests will differentiate &etween the pituitary and adrenal gland as the cause of hypercortisolism> a. Bigh dose de8amethasone suppression test &. C(B stimulation test c.
Cushing disease, the hypothalamic steroid receptors that allow negative feed&ac are intact &ut at a higher setpoint. #n this case, 17hydro8ycorticosteroid secretion does decrease significantly after high-dose de8amethasone administration. "drenal tumors, other causes of ectopic production of "C%B, and most cases of nodular hyperplasia do not respond to de8amethasone suppression with a decrease in steroid secretion. With an adrenal tumor, pituitary "C%B is already suppressed6 therefore, de8amethasone cannot suppress it further. With ectopic "C%B secretion, the tissue producing "C%B has no receptors for steroids and thus negative feed&ac cannot &e achieved. %herefore, high dose de8amethasone suppression will differentiate hypercortisolism of pituitary and adrenal srcins. 9otentially the most helpful new test for this purpose uses the administration of recom&inant C(B to release "C%B and conseuently to stimulate cortisol secretion. C(B 01 mg=g is administered intravenously, and serial &lood samples o&tained for 4 hours after administration. %he normal pituitary adrenal a8is responds &y a moderate increase in "C%B and cortisol. With Cushing disease, the "C%B and cortisol rise are accentuated. With adrenal autonomous production of cortisol and with ectopic "C%B production, there is virtually no response to C(B. ?7. Which of the following statements regarding androgens and estrogens in the fetus are true> a. %he development of normal female e8ternal genitalia reuires estrogen production &y the ovary &. " female with congenital adrenal hyperplasia is liely to &e masculinied in appearance c. %he development of normal male e8ternal genitalia reuires adrenal androgen production d. " male with congenital adrenal hyperplasia is liely to &e feminied in appearance "nswer! &, c "drenal androgens in the fetus stimulate wolffian duct development and elongate the genital tu&ercle. %hey promote midline migration of the la&ial folds and fusion of these folds to form the scrotum. %o complete the male transformation, the urethral opening migrates to the tip of the phallus. "ll of these events are androgen-dependent. Since the normal female fetus does not
secrete androgens, the genital tu&ercle, la&ial folds, and urethral opening all remain in the female position in this circumstance. %hus the female phenotype is associated with the a&sence of fetal se8 hormone production. E8cess androgen in the female fetus causes neonatal viriliation, as is seen with congenital adrenal hyperplasia. %he male infant with congenital adrenal hyperplasia is liely to have a normal appearance of the e8ternal genitalia as a neonate. 9recocious pu&erty will develop over a period of years in this latter circumstance. ?@. Which of the following statements regarding the physiology of the adrenal gland are true> a. (elease of C(B is regulated principally &y negative feed&ac &y "C%B &. 9lasma 17-etosteroid levels reflect the degree of adrenal cortisol production c. (enin undergoes enymatic cleavage in the lung to angiotensin # d. %he plasma half-life of "C%B is relatively long 0V 2 hrs e. +one of the a&ove "nswer! e %he pro8imate stimulator of cortisol production is the peptide hormone, andrenocorticotropic hormone 0"C%B. #t srcinates from the anterior pituitary gland and is regulated &y corticotropin-releasing hormone 0C(B. %he regulation of C(B is controlled &y various neural influences. %hese include intrinsic central nervous system influences and a negative feed&ac inhi&ition &y cortisol. "lthough there is some evidence of a short-loop feed&ac of "C%B on C(B, &oth slow and fast feed&ac &y cortisol on the pituitary release mechanism are the primary sources of clinically relevant C(B regulation. %he steroidogenic pathway involves the conversion of cholesterol to pregnenolone, progesterone, 17-hydro8yprogesterone, and then either to the adrenal androgens or cortisol via several intermediates. %he 17-etosteroids reflect adrenal androgen synthesis while the 17-hydro8ysteroids reflect cortisol synthesis.
(enin is produced predominantly in the :u8taglomerular apparatus of the idney where it acts locally and is released into the systemic circulation. (enin cleaves angiotensin #, a decapeptide derived from the liver which serves as renin su&strate. "ngiotensin # undergoes enymatic cleavage in the lung to angiotensin ##, which is the &iologically active form of the peptide. %he plasma half-life of "C%B is short 0measured in minutes with a rapid onset of action. %his is in contrast to a longer plasma half-life and a slower onset of action for cortisol itself.
?5. %he appro8imate ;-year survival rate for adrenocortical carcinoma is which of the following> a. A3 &. A3L;3 c. ;A3L?A3 d. +early 1AA3 "nswer! & %he prognosis for adrenocortical carcinoma is not good. %he overall ;-year survival rate is A3 to ;3 for these malignancies. When there is localied disease at the time of surgery, the ;-year survival may &e higher, in the 2A3 to ;A3 range. %he true prognosis in childhood is not clear, &ut the data suggest a -year survival rate of a&out A3.
7A. Which of the following statements is true with respect to pheochromocytoma> a. 9heochromocytoma associated with ME+ ##a is usually unilateral and
rarely malignant6 therefore, unilateral e8ploration through a posterior flan incision is usually sufficient &. Clonidine fails to suppress &asal plasma-catecholamine levels in patients with pheochromocytoma c. +9-;5 0141#-? &-iodomethyl-15-norcholesterol is taen up as cholesterol &y the adrenal medulla d. %he ratio of plasma 4,2-dihydro8yphenoglycol 0'B9 to norepinephrine is generally elevated in patients with pheochromocytoma compared to patients with essential hypertension "nswer! &, d 9heochromocytoma associated with the ME+ ##a syndrome is more often &ilateral and more often malignant, therefore, a&dominal e8ploration through an anterior approach is indicated. %he a&ility to measure catecholamines in the plasma has made possi&le the clonidine suppression test. #n patients without pheochromocytoma, clonidine suppresses high &asal plasma concentrations into the normal range, whereas concentrations in patients with pheochromocytoma are not suppressed. "nother use of plasma catecholamine measurements is in e8amining the ratio of 4,2-dihydro8yphenoglycol 0'B9 to norepinephrine in plasma. 'B9 is released from the chromaffin cells and adrenergic neurons to a much greater e8tent than norepinephrine in pheochromocytoma patients compared with patients who have essential hypertension, i.e. the ratio of 'B9 to norepinephrine is higher in patients with pheochromocytomas. +9-;5 0141#-? &-iodomethyl-15-norcholesterol is taen up as cholesterol &y the adrenal corte8 and is incorporated in the adrenocortical steroidogenic pathway. %his is a useful agent for imaging adrenocorticol lesions. 141#methaiodo&enylguanidine 0M#$ is a norepinephrine analogue that is useful in localiing pheochromocytomas throughout the &ody, especially when the tumors are multiple, e8traadrenal, recurrent, or metastatic.
71. Which of the following statements regarding aldosterone are true> a. #ts secretion is directly related to the serum potassium concentration &. "ngiotensin ## is a more potent regulatory factor than "C%B c. 9rimary hyperaldosteronism is characteried &y hyperalemia d. Secondary hyperaldosteronism occurs with renal artery stenosis "nswer! a, &, d "ldosterone secretion is controlled &y changes in the afferent arteriolar pressure in the renal corte8 as well as &y changes in sodium content in the renal tu&ule. %hese changes are sensed &y the :u8taglomerular apparatus and &y the macula densa and act through the renin angiotensin system. "t least two other factors influence aldosterone secretion. "ldosterone secretion is directly related to the serum potassium concentration. "n increase in serum potassium directly stimulates aldosterone production, whereas a decrease in serum potassium has the opposite effect. $ecause of its early point of action in the steroidogenic pathway, "C%B also increases secretion of aldosterone, although it is much less potent in this regard than in its stimulation of cortisol. %he stimulatory effects of potassium and "C%B on aldosterone secretion can &e overcome &y angiotensin ## stimulation. 9rimary hyperaldosteronism is characteried &y mineralocorticoid hypersecretion which promotes a positive sodium &alance and hypoalemia. "&out @A3 of patients with primary hyperaldosteronism have serum potassium levels of 4.; mE=< or less. Causes of secondary hyperaldosteronism are related to increased renin secretion. %hese include renal artery stenosis, congestive heart failure and renal salt-wasting.
7. " term neonate is noted to have am&iguous female genitalia. %his infant is at ris for which of the following potentially life-threatening pro&lems> a. Cardiomyopathy with congestive heart failure &. Sodium wasting nephropathy with hypovolemia c. (espiratory failure from surfactant deficiency d. Spontaneous hemorrhage from throm&ocytopenia e. 9ulmonary em&olus from a hypercoagua&le state "nswer! & Enymatic defects in the steroidogenic pathway produce a syndrome nown as congenital adrenal hyperplasia. %his syndrome presents predominantly in the neonatal period with se8ual am&iguity. %hese enymatic defects result in a lowered cortisol secretion. %he specific enyme defects present determine the clinical form of the syndromes. %hese include a 1-hydro8ylase deficiency, an 11&-hydro8ylase deficiency, and a 17-hydro8ylase-deficiency. %he 1-hydro8ylase deficiency and the 11&-hydro8ylase deficiency result in e8cess androgen production in utero and result in masculiniation with am&iguous genitalia in the female new&orn. Masculiniing effects in the male may not &e detected until precocious pu&erty &ecomes o&vious. "&out 2A3 of patients with 1-hydro8ylase deficiency, the most common form, have salt-wasting or sodium loss &y urine. Bypovolemic shoc can result. Cardiomyopathy, respiratory failure, throm&ocytopenia and pulmonary em&oli are not associated with this syndrome.
74. Which of the following adrenal lesions can &e treated definitively &y medical means> a. $enign functional adrenocortical adenoma
&. "drenocortical carcinoma c. Congenital adrenal hyperplasia d. Cushing disease e. 9heochromocytoma "nswer! c %he treatment of adrenal tumors is primarily surgical removal. "lthough pharmaceutical agents are useful in preparing the patient for surgery or in palliating the patient with recurrent adrenal carcinoma, no agents render definitive therapy for adrenal tumors. Congenital adrenal hyperplasia stands alone among the primary, hyperfunctioning adrenal syndromes that are amena&le to medical therapy for definitive treatment. /unctioning &enign lesions of the adrenal corte8 that are not "C%B dependent, such as adenomas or macronodular hyperplasia, respond to metyrapone and aminoglutethimide, which are inhi&itors of enymes in the adrenal steroidogenic pathway. $oth agents can effect a decrease in the production of cortisol when there is no increase in "C%B secondary to feed&ac stimulation. %hese drugs are not satisfactory long-term agents &ecause of their high incidence of drug reactions, patient noncompliance, and continued growth of the lesions. %hey may &e useful in patients whose surgery must &e delayed. "lthough malignant, functioning adrenocortical lesions should &e de&uled whenever possi&le. Several chemotherapy agents offer ad:unct therapy. %he most noteworthy is mitotane 0o,p,-'''. %his is a cytolytic agent that has a 4A3 to 7A3 response rate in terms of decreasing steroid output. )nfortunately, patient survival is not affected. "s mentioned, nonoperative treatment with cortisone acetate and possi&ly fludrocortisone is definitive therapy for congenital adrenal hyperplasia. Cushing disease is &est treated &y transsphenoidal resection of the pituitary adenoma. 9heochromoctyoma reuires definitive surgical resection although the preoperative pharmacologic preparation with catecholamine &locade is reuired.
72. Which of the following statements regarding the pituitary gland are true> a. "'B is a product of the neurohypophysis &. %he preferred surgical approach to the pituitary gland is via the sphenoid sinus c. rowth hormone, "C%B,
corticotropin-releasing hormone, to stimulate adrenocorticotropic hormone 0"C%B6 04 growth hormone-releasing hormone, to stimulate secretion of growth hormone 0B6 02 gonadotropin-releasing hormone, to stimulate luteiniing hormone 0
7;. Which of the following statement0s is=are true with respect to growth hormone secreting pituitary adenomas> a. /ewer than ;A3 of patients will have growth hormone levels over 1A ng=m< &. *ral glucose administration suppresses growth hormone levels in patients with acromegaly c. *ver @A3 of growth hormone-secreting microadenomas can &e cured with transphenoidal resection d. 9reoperative treatment of macroadenomas with a somatostatin analogue may improve postoperative remission rates "nswer! c, d %he endocrine diagnosis of acromegaly rests largely on serum growth hormone 0B levels, &ecause 5A3 of patients will have levels over 1Ang=m<. When acromegaly is apparent &ut consistently elevated growth hormone levels are not o&tained, the glucose suppression test is the most
useful diagnostic procedure. #n normal patients, 1 to hours after the oral administration of 1AA g of glucose, the growth hormone level falls well &elow ; ng=m<. %his suppression is not seen with B-secreting adenomas, and often a parado8ical rise in B is o&served. %he goals of treatment are to lower the circulating growth hormone or somatomedin C levels to within a normal range and to reduce the sie of the mass lesion causing compression-related symptoms. When a microadenoma is removed transsphenoidally, endocrine remission may &e e8pected in @A3 to @@3 of cases. When a macroadenoma is resected, postoperative remission is reported in 4A3 to ?@3 of cases. %he rate of remission is inversely related to preoperative B levels and tumor sie. 9reoperative treatment of macroadenomas with a somatostatin analogue may improve postoperative remission rates.
7?. " 4A-year-old woman presents with amenorrhea, headache and &itemporal hemianopsia. "ppropriate diagnostic tests include! a. Cere&ral angiography &. Serum prolactin levels c. Magnetic resonance imaging of the &rain d. "&dominal and pelvic C% scan "nswer! &, c 9atients with pituitary lesions present symptoms and signs related to a mass effect on the pituitary and its surrounding structures, to hypersecretion of the hormones &y the lesion itself, or to a com&ination of &oth. "s mass lesions in the pituitary enlarge, they encounter the various contents of the cavernous sinuses, including the third, fourth, si8th and first two divisions of the fifth cranial nerves, as well as the internal carotid artery. %he growth of a tumor in
the relatively unrestricted upward direction is much more common and often results in compression of the optic chiasm with the resultant loss of vision, typically a &itemporal hemianopsia. 9rolactin-secreting pituitary adenomas often present with endocrine symptoms including amenorrhea and galactorrhea in women. #n men, the loss of li&ido, infertility and visual loss are typical. Magnetic resonance imaging 0M(# has evolved as the first choice for diagnostic imaging and is often the only tool needed to reach a therapeutic decision with regard to pituitary adenomas. With intravenous infusion of a paramagnetic su&stance such as gadolinium, M(# demonstrates intrasellar tumors as small as ; mm. #n addition, the e8tent of suprasellar and sphenoid sinus e8tension, as well as lateral e8tension into the cavernous sinuses, is demonstra&le. Cysts and hemorrhage can &e differentiated, as can &lood flowing within an aneurysm. C% scanning has a place in pituitary imaging if M(# scanning is unavaila&le. 9lain sull R-rays are not needed generally. Cere&ral angiography is performed only if an aneurysm is suspected or if a lesion is so large that occlusion or compression of the internal carotid artery is in uestion. /or this patient, the symptoms clearly point to a central nervous system, pituitary etiology rather than a&dominal end organ failure with regard to the amenorrhea.
77. Which of the following condition0s is=are associated with hyperprolactinemia> a. Chronic renal failure &. E8ogenous estrogen administration c. 'ia&etes mellitus d. Cirrhosis "nswer! a, &, d
Elevated serum prolactin levels do not always indicate the presence of a pituitary tumor. #mportant alternative causes are chronic renal failure, hypothyroidism, various drugs including phenothiaines, tricyclic antidepressants, e8ogenous estrogen, opiates, reserpine, verapamil and others. #n addition, hepatic disease, pregnancy and a variety of pituitary and hypothalamic lesions cause hyperprolactinemia. #f the prolactin level is over 1;A ng=ml, a pituitary tumor is almost invaria&ly the cause, &ut often microadenomas produce prolactin levels of less than 1AA ng=ml. %he sie of pituitary tumors has &een shown to relate to the degree of prolactin elevation, which may reach into the thousands of nanograms per milliliter. %here are no relia&le provocative tests to differentiate prolactinomas from other causes of hyperprolactinemias, so the diagnosis relies on ruling out other causes and imaging of the adenoma.
7@. 9ituitary adenomas are &est classified according to functional hormone output. %his information may &e derived from which of the following> a. Bemato8ylin and eosin staining &. #mmunohistochemical staining of pituitary tissue c. #n situ hy&ridiation studies d. Selective venous sampling from the inferior petrosal sinuses "nswer! &, c, d 9ituitary adenomas have &een classified historically as acidophilic, &asophilic and chromopho&ic. "denomas may show a varia&le staining pattern with conventional hemato8ylin and eosin dyes, so it is difficult to classify adenomas &ased on these stains. #mmunohistochemistry, ultrastructural studies and in situ hy&ridiation analyses for specific hormones are the most relia&le methods of classifying pituitary adenomas today.
#mmunohistochemical staining of pituitary adenomas with specific anti&odies has relia&ly classified adenomas using highly purified polyclonal and monoclonal anti&odies against prolactin, B, "C%B, /SB-&
75. Which of the following statements is true with respect to Cushing 'isease> a. 9ituitary microadenomas are often small and deep within the gland itself &. %he treatment of choice for hypercortisolism due to a pituitary adenoma in women of child&earing age is transsphenoidal total hypophysectomy c. 9atients who fail to remit with &oth surgery and radiation to the pituitary reuire either medical or surgical adrenalectomy d. %he long-term recurrence rate after resection of an "C%B-producing pituitary microadenoma is appro8imately 2A3 "nswer! a, c 9ituitary microadenomas secreting "C%B may &e very small and are often
located deep within the gland itself. #f the tumor is not evident on opening the dura, incisions must &e made into the gland and internal e8ploration carried out. #f no tumor is identified, then a decision must &e made as to whether to resect all or a portion of the gland. #f the endocrine evidence is convincing for pituitary srcin and the patient has no desire to have children, then total hypophysectomy is warranted. #f the petrosal sinus sampling clearly indicates laterality then appropriate hemiresection of the gland may &e done. "&out 7;3 of patients have microadenomas as the source of "C%B secretion. %he postoperative remission rate in these patients is @@3 to 5?3, and the long-term recurrence rate appears to &e no more than ;3. 1A3 to A3 of patients who undergo e8ploration have macroadenomas, and the postoperative remission rates in these patients have &een reported to &e from 443 to ?13. Most of these patients reuire postoperative radiation therapy. 9atients who fail &oth surgery and radiation reuire either surgical adrenalectomy or medical suppression of adrenal function.
@A. " 2; year-old woman presents for evaluation of hypertension, recent onset o&esity, hirsutism and depression. Cere&ral M(# does not show a pituitary lesion. Evaluation may include determination of which of the following> a. "M serum cortisol levels after low dose de8amethasone suppression &. Simultaneous serum "C%B measurement in peripheral and inferior petrosal sinus sites c. Chest and a&dominal C% scan d. )rinary free cortisol e8cretion "nswer! &, c, d %he findings of Cushing Syndrome often include central o&esity,
hypertension, hirsutism, fatigue, easy &ruisa&ility, stria, moon-lie facies, dorsal fat pad, and often depression or other mental changes.
@1. %he most common mass lesion in the sella turcica is which of the following> a. Craniopharyngioma &. "neurysm c. $enign pituitary cyst d. 9ituitary adenoma "nswer! d 9ituitary adenomas are the most common mass lesions in the sella turcica or parasellar region. %hey constitute @3 to 1A3 of all &rain tumors. *ccasionally, they are cystic and may &e confused with other lesions. Craniopharyngiomas are the ne8t most common tumor, although these are more often suprasellar in location. %hese are more common in children, &ut up to one third occur in adults. %hey are usually cystic and are calcified in 7A3 of children and 2A3 of adults. More rare lesions include meningiomas, germinomas, metastatic malignancies from lung and &reast primaries, gliomas, dermoids and &enign epidermoid. (athe cysts, aneurysms, and a variety of inflammatory and granulomatous processes.
@. 9harmacologic treatment of growth hormone 0B e8cess secondary to a pituitary adenoma may include the use of which of the following> a. $romocriptine &. Gasopressin c. *cteotide d. 9rednisone "nswer! a, c
$romocriptine, a dopamine receptor agonist, has &een demonstrated to lower B levels in 713 of 1? acromegalic patients. " clinical response was achieved in up to 5;3 of acromegalic patients, and reduced somatomedin C levels were found in some patients with persistently elevated B levels. $romocriptine does not appear to &e an effective primary treatment for acromegaly, &ut may help to control B and somatomedin C levels as an ad:uvant therapy. " somatostatin analogue, octeotide, has recently &een used to treat acromegaly and has &een demonstrated to significantly reduce B and somatomedin C levels in most patients and normalie values in ;A3. %his treatment provides only minimal tumor shrinage, and B levels rise again immediately following cessation of the drug. %his drug may prove to &e useful as a preoperative treatment or in surgical failures. Gasopressin and prednisone have no role in the treatment of acromegaly.
