USMLE WORLD STEP 2 CK 2*
(INTERNAL (INTERN AL MEDICINE) MEDICINE ) *Block
BLOCK # 2
47 48 49
Internal Medicine Internal Medicine Internal Medicine
Cardiology Neurology Respiratory
70 71 7
Internal Medicine Internal Medicine Internal Medicine
Miscellaneous Ophthalmoloqy Respiratory
!0 !1
Internal Medicine Internal Medicine
Cardiology #iostatistics
7" 74
Internal Medicine Internal Medicine
Neurology $N%
! !" !4 !!
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
Rheumatology Neurology Respiratory I(
7! 7' 77 78
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
&I% I( $lectrolytes )em*Onc
!' !7
Internal Medicine Internal Medicine
Ophthalmology )em*Onc
79 80
Internal Medicine Internal Medicine
$ndocrinology Respiratory
!8 !9 '0 '1
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
)em*Onc +oisoning )epatology Neurology
81 8 8" 84
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
Respiratory )epatology $N% I(
' '" '4 '!
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
#iostatistics Miscellaneous (ermatology &I%
8! 8' 87 88
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
#iostatistics Cardiology )em*Onc &enitourinary
'' '7 '8 '9
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
I( $lectrolytes )epatoloqy &I%
89 90 91 9
Internal Medicine Internal Medicine Internal Medicine Internal Medicine
Neurology #iostatistics I( )em*Onc
__________________________________________________________
53
USMLE WORLD STEP 2 CK 2*
(INTERNAL (INTERN AL MEDICINE) MEDICINE ) *Block
#$%&e 'le % !ecoe!%+ #ell ,!o' $% c&e Q NO 47: A 56-ye!-ol" #$%&e &e!%o! #ll Ml &$& # &!e&e" #%&$ &$!o'.oly&%c &$e!/y 0 "y +o1 O "y 0 o, $% $o/%&l%&%o3 $e "eelo/ "eelo/ e# c$e& /% &$& % %'%l! &o $% /!e%o /% o, 'yoc!"%l %,!c&%o % ee!%&y3 !"%&%o " c$!c&e!1 T$e /% % o& !el%ee" .y .l%+l %&!o+lyce!%1 %&!o+lyce!%1 4e % $e'o"y'%clly $e'o"y'%clly &.le1 4% l+ ,%el" !e cle! " $e!& o" !e o!'l1 EK $o# $y/e!c&e#e " e# ST e+'e& ele&%o % le" 783 723 " 791 4e % /ec&e" &o $e !e-%,!c&e"1 W$%c$ o, &$e ,ollo#%+ .%o'!ke! o, c!"%c %:!y c e&.l%$ &$e "%+o% o, !e-%,!c&%o % &$% e&&%+;
A.
Cardiac troponin I B. Cardiac troponin I C. LDH D. CR-MB E. Myoglobin Explanation:
Explanation: CK-MB fraction ha a high p!cificity for an ac"t! MI #lightly lo$!r than cardiac troponin%. It b!gin to ri! $ithin &-' ho"r aft!r Ml and r!t"rn to ba!lin! $ithin &(-)* ho"r. It+ high p!cificity and rapid r!t"rn to th! ba!lin! ,a! it th! bio,ar!r of choic! for th! diagnoi of a r!c"rr!nt MI. Cardiac troponin I and cardiac troponin I ar! prot!in that control th! int!raction of actin and ,yoin. h!y ar! ,or! p!cific than all th! oth!r bio,ar!r of cardiac in/"ry b!ing "!d for th! diagnoi of MI. h!y b!gin to ri! &-' ho"r aft!r an MI0 and r!,ain !l!1at!d for 23 day. h!y ha1! no$ b!co,! th! pri,ary bioch!,ical t!t "!d for th! diagnoi of ac"t! MI. h!y ha1! alo r!plac!d LDH for th! r!trop!cti1! diagnoi of MI. B"t b!ca"! of th!ir p!rit!nt !l!1ation for 23 day aft!r an MI0 th!y can+t b! "!d to !tablih th! diagnoi of r!-infarction $ithin 2-* $!! aft!r an MI. LDH i pr!!nt in cardiac ,"cl! and oth!r ti"! li! r!d c!ll0 idn!y0 li1!r0 and !l!tal ,"cl!. It b!gin to ri! $ithin &-' ho"r0 r!ach! it p!a in *&-&( ho"r and r!,ain !l!1at!d for '-) day. B!ca"! of it lo$ p!cificity and p!rit!nt !l!1ation0 it i not "!f"l for th! diagnoi of a r!-infarction. It ha alo b!!n r!plac!d by cardiac troponin for th! r!trop!cti1! diagnoi of MI a it lac p!cificity. Myoglobin i a h!,!-prot!in fo"nd in ,any ti"!. It ha a rapid ri! and r!t"rn to th! ba!lin! aft!r an ac"t! Ml. It can b! "!d to d!t!ct r!c"rr!nt in/"ry b"t b!ca"! of lac of p!cificity0 CK-MB i a b!tt!r choic!. Ed"cational 4b/!cti1!: E,phai5! th! i,portanc! of CK-MB for th! diagnoi of r!c"rr!nt ,yocardial infarction.
54
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL (INTERN AL MEDICINE) MEDICINE ) *Block
Q NO 48: A 26-ye!-ol" ' co'e &o &$e e'e!+ecy "e/!&'e& .ece $e % <,,e!%+ ,!o' &$e #o!& $e"c$e o, $% l%,e1= 4e ,eel e&e" " % /$o&oe%&%e1 4% .loo" /!e!e % 86>?>'' 4+1 $e!& !&e % @9'%3 " &e'/e!&!e % 9615C (?1)1 T$e /$y%cl e'%&%o !eel o ,ocl e!olo+%cl y'/&o'3 ece/& ,o! o'e 'e%+%' " e!&%+o3 #$%c$ % o& locl%e" &o e%&$e! %"e1 CS e'%&%o !eel &$e /!eece o, &$oc$!o'%1 W$& % &$e ':o! ce o, 'o!.%"%&y " 'o!&l%&y % /&%e& #%&$ &$e .oe co"%&%o; A. B. C. D. E. .
6ot-angiographic co,plication 7aopa, $ith y,pto,atic ich!,ia and infarction 8!condary inf!ction 6ot-"rgical co,plication 9i,odipin! "! Cardior!piratory arr!t fro, incr!a!d C8 pr!"r!
Explanation:
hi pati!nt ha a "barachnoid h!,orrhag!0 and i at ri for "b!;"!nt 1aopa, of th! art!ri! at th! ba! of th! brain. 7aopa, follo$ing 8AH occ"r in approxi,at!ly <3= of pati!nt0 and i th! ,a/or ca"! of ,orbidity and ,ortality in "ch pati!nt. In aff!ct!d pati!nt0 th! ign of ich!,ia ""ally app!ar in abo"t ) day aft!r th! 8AH. #Choic! E% Calci", chann!l bloc!r #!.g.0 ni,odipin!% ar! "!d to pr!1!nt 1aopa, in pati!nt $ith 8AH. #Choic! A0 C0 and D% 8!condary inf!ction0 a $!ll a co,plication aft!r angiography and "rg!ry0 ar! not a pr!1al!nt a 1aopa, follo$ing 8AH. Ed"cational 4b/!cti1!: 7aopa, i th! ,a/or ca"! of ,orbidity and ,ortality in pati!nt $ith "barachnoid h!,orrhag! #8AH%. Calci", chann!l bloc!r #!.g.0 ni,odipin!% ar! "!d to pr!1!nt 1aopa, in pati!nt $ith 8AH.
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55
USMLE WORLD STEP 2 CK 2*
(INTERNAL (INTERN AL MEDICINE) MEDICINE ) *Block
Q NO 49: A 66-ye!-ol" ' % "'%&&e" &o &$e $o/%&l ,&e! $e "eelo/e" ee!e .!e&$lee1 4e # % $% l &&e o, $el&$ 9 "y +o #$e $e "eelo/e" ,ee! #%&$ !%+o! " /!o"c&%e co+$1 T$e /&' % +!ee%$ % colo! " 'ell ."1 4e !e/o!& 8>> /ck-ye! /ck-ye! $%&o!y o, 'ok%+1 4e # &!&e" o %&$!o'yc% lo+ #%&$ &$e //le'e&l oy+e3 %/!&!o/%' %$le!3 l.&e!ol %$le! " I7 'e&$ /!e"%oloe1 O /$y%cl e'%&%o3 $% /le % ?6'%3 Bloo" P!e!e 8>>6>'' 4+ Te'/e!&!e % 8>2 " Re/%!&o!y R&e % 20'%1 4% l+ e'%&%o !eel !le ll oe! &$e c$e& lo+ #%&$ occ%ol !$oc$%1 E/%!&o!y E/%!&o!y /$e % /!olo+e"1 EK !eel 'l&%,ocl &!%l &c$yc!"%1 W$%c$ o, &$e ,ollo#%+ +e& #%ll #o!e &$e !!$y&$'%; A. B. C. D. E.
A5ithro,ycin 4xyg!n Ipratropi", inhalation Alb"t!rol inhalation M!thyl pr!dniolon!
Explanation:
Explanation: h! pati!nt ha ,"ltifocal atrial tachycardia0 $hich i aociat!d $ith th! !xac!rbation of chronic obtr"cti1! p"l,onary di!a! #C46D%. hi pati!nt n!!d ,!a"r! to r!d"c! th! !1!rity of hypox!,ia. h! th!rapy for thi chaotic atrial tachycardia i dir!ct!d pri,arily againt th! "nd!rlying di!a!. Ho$!1!r0 o,! ag!nt li! th!ophyllin! and b!ta agonit ,ay act"ally $or!n th! arrhyth,ia. 8o th!y ,ay b! "!d /"dicio"ly. h! pati!nt ho"ld b! !1al"at!d for any "nd!rlying !l!ctrolyt! i,balanc!. R!,!,b!r b!ta agonit alo ha1! th! t!nd!ncy to lo$!r th! potai", l!1!l0 $hich ha1! f"rth!r arrhyth,ic !ff!ct. A5ithro,ycin0 Ipratropi", and t!roid ha1! no !ff!ct on th! arrhyth,ia. 4xyg!n $ill h!lp to top th! arrhyth,ia. Ed"cational 4b/!cti1!: Kno$ ho$ to ,anag! 1ario" clinical it"ation in !xac!rbation of chronic obtr"cti1! p"l,onary di!a!.
56
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL (INTERN AL MEDICINE) MEDICINE ) *Block
Q NO 50: A 0>-ye! ol" ,e'le %''%+!& ,!o' A% co'e ,o! el&%o o, $e! "y/e1 4e! "y/e # '%l" 6 'o&$ +o .& %& $ o# /!o+!ee" &o "y/e3 ee & !e&1 S$e "e%e y c$e& /%3 yco/e3 o! /l/%&&%o1 /l/%&&%o1 S$e % o-'oke! " o-lco$ol%c1 o-lco$ol%c1 4e! /& 'e"%cl $%&o!y % %+%,%c& ,o! /l'o!y &.e!clo%1 4e! PR @2'% BP 895> ''4+ Te'/e!&!e 918C (?@1@) RR 80'%1 O $e! e'%&%o3 %+%,%c& /$y%cl ,%"%+ !e :+l! eo "%&e%o3 .%l&e!l kle e"e'3 " &e"e! $e/&o'e+ly1 C$e& -!y $o# /e!%c!"%l clc%,%c&%o1 W$%c$ o, &$e ,ollo#%+ e& o, /$y%cl ,%"%+ % 'o& l%kely &o .e /!ee& % &$% /&%e&; A. Early third h!art o"nd and inpiratory incr!a! in /"g"lar 1!no" p"l! B. >at!r ha,,!r p"l! and pitol hot f!,oral C. apping ap!x b!at and ,alar fl"h D. 6"l" paradox" and hypot!nion . 6anytolic ,"r,"r at l!ft lo$!r t!rnal bord!r Explanation:
hi pati!nt0 ,ot li!ly0 ha contricti1! p!ricarditi. h! finding of p!ricardial calcification on th! ch!t ?-ray i an i,portant cl"!. h! !tiology of p!ricarditi i probably fro, h!r prior hitory of "b!rc"loi. h! !arly third h!art o"nd0 that i alo call!d p!n cardial noc and th! inpiratory incr!a! in th! /"g"lar 1!no" pr!"r! #K",a"l+ ign%0 ar! i,portant phyical finding of contricti1! p!ricarditi. K",a"l+ ign i alo pr!!nt in right id!d h!art fail"r!0 !1!r! tric"pid r!g"rgitation0 right 1!ntric"lar infarction and cardiac ta,ponad!. >at!r ha,,!r or collaping p"l! and pitol hot f!,oral p"l! ar! diagnotic cl"! to aortic r!g"rgitation. h!! phyical finding occ"r d"! to a hyp!rdyna,ic circ"lation and !arly diatolic r"noff of aortic in"ffici!ncy. apping ap!x b!at and ,alar fl"h ar! i,portant phyical finding of ,itral t!noi. 6"l" paradox" i d!fin!d a gr!at!r than 23-,,Hg fall of th! ytolic blood pr!"r! d"ring inpiration. 6"l" paradox" and hypot!nion point to$ard th! diagnoi of p!ricardial ta,ponad!. h! for,!r i "nco,,on in contricti1! p!ricarditi "nl! an !ff"ion i pr!!nt. It ,ay alo b! pr!!nt in !1!r! air$ay obtr"ction and "p!rior 1!na ca1a obtr"ction. A panytolic ,"r,"r at th! l!ft t!rnal bord!r i ""ally !!n in tric"pid r!g"rgitation. Ed"cational 4b/!cti1!: Kno$ th! charact!ritic clinical finding of contricti1! p!ricarditi.
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57
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 51: A +!o/ o, %e&%+&o! !e /l%+ &"y &o el&e &$e !el&%o$%/ .e&#ee e!' ,%.!%o+e leel " &$e %c%"ece o, c&e co!o!y y"!o'e1 T$ey 'e &$& e!' ,%.!%o+e leel % o!'lly "%&!%.&e" !%.le % &$e /o/l&%o o, %&e!e&1 W$%c$ o, &$e ,ollo#%+ &&e'e& % 'o& co%&e& #%&$ &$% '/&%o; A. B. C. D. E.
M!an i gr!at!r than ,!dian M!an i gr!at!r than ,od! M!an i !;"al to ,!dian M!dian i gr!at!r than ,!an Mod! i gr!at!r than ,!an
Explanation:
h! nor,al ditrib"tion i on! of th! ,ot pop"lar tatitical ditrib"tion. Int!r!tingly0 ,any 1ariabl! in r!al lif! #!.g.0 laboratory 1al"!% ar! nor,ally ditrib"t!d or clo! to nor,al. h! nor,al ditrib"tion ha o,! nic! tatitical prop!rti!0 and i !ay to $or $ith. It i b!ll-hap!d and y,,!tric. Con!;"!ntly0 all it ,!a"r! of c!ntral t!nd!ncy ar! !;"al: ,!an @ ,!dian @ ,od! #In r!al lif!0 th! 1al"! ar! 1!ry clo! to !ach oth!r%. 8!$!d ditrib"tion do not ha1! thi prop!rty. #Choic! A and B% In a poiti1!ly !$!d ditrib"tion #tail on th! right%0 th! ,!an i gr!at!r than th! ,!dian and gr!at!r than th! ,od!. #Choic! D and E% In a n!gati1!ly !$!d ditrib"tion #tail on th! l!ft%0 th! ,!an i l! than th! ,!dian and l! than th! ,od!. Ed"cational 4b/!cti1!: A nor,al ditrib"tion i y,,!tric and b!ll hap!d. All it ,!a"r! of c!ntral t!nd!ncy ar! !;"al: ,!an @ ,!dian @ ,od!.
58
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 52: A 65-ye!-ol" #$%&e 'le /!ee& #%&$ ee!e /% " #eke o, &$e !%+$& $ol"e!1 4% /% % #o!ee" #$e $e &!%e &o /o%&%o $% !' .oe &$e $ol"e! leel o! #$e $e /ll o! /$e1 4e lo co'/l% o, %+$& /% #$e $e l%e oe! &$e ,,ec&e" $ol"e!1 4e % .le &o !ec$ oe!$e" " cF& l%,& y&$%+ #%&$ o&&!e&c$e" !'1 4e $ 0> /ck-ye! $%&o!y o, c%+!e&&e 'ok%+ " % c$!o%c lco$ol%c1 4e $ o o&$e! %+%,%c& 'e"%cl /!o.le'1 4% ,&$e! "%e" o, 'l&%/le 'yelo'1 4% %&l !e &.le " $e % ,e.!%le1 O e'%&%o3 &$e!e % l%'%&&%o o, '%" !c ."c&%o " e&e!l !o&&%o &$& "oe o& %'/!oe ,&e! l%"oc%e %:ec&%o1 T$e!e % o #ell%+3 !e"e o! #!'&$1 4% e!ocl! && % %&c&1 W$& % &$e 'o& //!o/!%&e e& &e/ &o "%+oe $% /!o.le';
A. ? ray
ho"ld!r B. Ch!t-?-ray C. 8!r", i,,"no!l!ctrophor!i D. MRI of th! ho"ld!r E. Apiration of th! /oint . Bon! can Explanation:
Explanation: hi pati!nt ,ot li!ly i "ff!ring fro, rotator c"ff t!ar $hich pr!!nt $ith ho"ld!r pain aggra1at!d by ,o1!,!nt li! p"hing0 p"lling and poitioning th! ar, abo1! th! ho"ld!r a $!ll a $!an! of ho"ld!r r!"lting in f"nctional i,pair,!nt. Exa,ination ,ay ho$ li,itation of ,id arc abd"ction or !xt!rnal rotation or both $hich do! not r!1!r! $ith lidocain! in/!ction th" diff!r!ntiating th! rotator c"ff t!ar fro, rotator c"ff t!ndiniti. D!finiti1! diagnoi of rotator c"ff t!ar r!;"ir! MRI or arthrography. MRI ho"ld b! p!rfor,!d $h!n rotator c"ff t!ar i "p!ct!d on clinical gro"nd and pati!nt ha no oth!r !rio" ,!dical probl!, that $ill ,a! th! corr!cti1! "rg!ry diffic"lt. h! abo1! pati!nt do! not ha1! any !rio" ,!dical probl!, and hi y,pto, ar! incapacitating and h! i 1!ry li!ly to b! b!n!fit!d fro, "rg!ry. Apiration of th! /oint i indicat!d $h!n th!r! i "picion for !ptic or crytal ind"c!d arthriti. h! abo1! pati!nt ha no $!lling0 $ar,th or r!dn! of hi /oint and !ptic arthriti0 go"t and p!"dogo"t ar! highly "nli!ly in thi pati!nt. ho"gh thi pati!nt ha fa,ily hitory of ,"ltipl! ,y!lo,a0 hi clinical pict"r! i not co,patibl! $ith th! diagnoi of ,"ltipl! ,y!lo,a and th!r! i no n!!d for bon! can or !r", i,,"no!l!ctrophor!i. h! only probl!, that thi pati!nt ha i ho"ld!r pain and $!an! that i ,ot li!ly d"! to rotator c"ff t!ar and ch!t x-ray i not going to b! h!lpf"l in ,aing th! diagnoi. Rath!r plain x-ray of th! ho"ld!r not plain ch!t x-ray i r!co,,!nd!d $h!n th!r! i "picion of ho"ld!r pathology. 4blit!ration or narro$ing of acro,ioh",!ral pac! $ill b! !!n in co,pl!t! t!ar. Calcification ,ay alo b! !!n in chronic ca!. Ed"cational 4b/!cti1!: MRI i th! d!finiti1! diagnotic t"dy for rotator c"ff t!ar.
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59
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 53: A 29-ye!-ol" #$%&e ' % .!o+$& &o &$e e'e!+ecy "e/!&'e& (ED) .y '.lce "e &o e/%le/&%c e%!e1 4e ,ell o &$e %"e#lk #$%le +o%+ $o'e ,!o' /.3 #$e!e $e $" &#o .ee!1 A #%&e o&e" &o%c-clo%c 'oe'e& o, ll ,o! e&!e'%&%e ,o! .o& oe '%&e1 T$% e%!e # $% ,%!& e/%o"e3 " l&e" 9> '%&e1 I &$e ED3 $e % % &&e o, /!&%l co,%o " "%o!%e&e" &o &%'e3 /lce " /e!o1 T$e /$y%cl e'%&%o "oe o& !eel y ,ocl e!olo+%c /&$olo+y1 4% eye e' "oe o& $o# y //%lle"e'1 4% %!#y % ec!e"3 " $% .!e&$%+ % o!'l1 CBC3 e!' elec&!oly&e3 EK " c$e& -!y !e o!'l1 U!%e &o%colo+y c!ee % o!"e!e"3 " lo!e/' % +%e1 W$& % &$e 'o& //!o/!%&e e& &e/ % &$e '+e'e& o, &$% /&%e&;
A.
6ychiatric con"ltation B. Brain co,p"t!d to,ography $itho"t contrat C. Brain co,p"t!d to,ography $ith contrat D. L",bar p"nct"r! E. El!ctro!nc!phalogra, Explanation:
In a pati!nt $ho pr!!nt $ith focal n!"rologic ign and y,pto, and an "ncl!ar hitory0 iti !!ntial to rapidly !xcl"d! lif!-thr!at!ning proc!! "ch a an intracranial h!,orrhag! th!r!for!0 th! ,ot appropriat! initial t!t in thi ca! i a C can $itho"t contrat. "rth!r ,anag!,!nt i d!p!nd!nt on th! C finding. In addition0 thi pati!nt ,ay b! load!d $ith Dilantin to "ppr! or pr!1!nt !i5"r! acti1ity. #Choic! B% C $ith contrat i ""ally indicat!d if brain t",or or oth!r ,a l!ion #toxopla,oi0 ly,pho,a0 canc!r% i th! "p!ct!d ca"! of th! pati!nt+ y,pto,. If th! non contrat C !xcl"d! th! h!,orrhag!0 th!n MR or C $ith contrat of th! brain i th! n!xt t!p. #Choic! D% A l",bar p"nct"r! i not indicat!d in an af!bril! pati!nt $ith no ,!ning!al ign. #Choic! E% EE i th! gold tandard for th! doc",!ntation of !pil!ptifor, acti1ity. Ho$!1!r0 thi i not th! n!xt t!p. #Choic! A% 6ychiatric con"ltation i ""ally don! $h!n th!r! i !1id!nc! of dr"g intoxication. Ed"cational 4b/!cti1!: C can of th! h!ad $itho"t contrat i th! initial diagnotic t!t of choic! $h!n a pati!nt pr!!nt $ith i,pair!d concio"n! or !i5"r! or focal n!"rologic ign.
60
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 54: A 50-ye!-ol" 'le "e!+oe co'/le ."o'%l o/e!&%o1 T#o "y l&e! $e .eco'e $o!& o, .!e&$ " &c$y/e%c1 4e !eG%!e 'ec$%cl e&%l&%o1 4% c$e& -!y !eel .%l&e!l ,l,,y %,%l&!&e1 4e'o"y'%c !eel &$& &$e /&%e& % o& % co+e&%e $e!& ,%l!e3 !e/e&e" /&' cl&!e !e e+&%e " $% 7H c % o, lo# /!o..%l%&y1 4% WBC co& % 8>3>>>c'' #%&$ 8 ."1 T$e /&%e& co&%e &o .e "%,,%cl& &o oy+e&e1 T$e /&%e& 'o& l%kely $ A. B. C. D. E.
6n!",onia At!l!ctai ARD8 6"l,onary !,boli, 6n!",othorax
Explanation:
In a potop!rati1! pati!nt $ho pr!!nt $ith dypn!a and tachypn!a0 on! ha to !xcl"d! Ml0 6E0 pn!",onia and ARD8. In th! abo1! pati!nt0 th!r! i no !1id!nc! of h!art fail"r! and all th! p"t", c"lt"r! ar! n!gati1!. In addition hi 7 can i n!gati1! o th! probability of a 6E i lo$. In th! pr!!nc! of bilat!ral fl"ffy infiltrat! and hypoxia $ith a diffic"lty in oxyg!nation0 th! diagnoi of ARD8 ,"t b! !nt!rtain!d. h! !arli!t ign i oft!n tachypn!a follo$!d by dypn!a. h! phyical !xa, and ch!t x-ray ar! ""ally nor,al initially. Choic! A: 6n!",onia can d!finit!ly pr!!nt in a potop!rati1! pati!nt. Ho$!1!r0 in th! abo1! pati!nt0 th! p"t", c"lt"r! ar! n!gati1!. 6n!",onia g!n!rally occ"r fro, thr!!-to-!1!n day alt!r "rg!ry. 8o,!ti,! if th! p"t", c"lt"r! ar! n!gati1! and "picion i high for pn!",onia0 bronchocopic c"lt"r! ar! obtain!d. h! pati!nt $ith pn!",onia ,ay ha1! !xc!i1! !cr!tion0 f!1!r and an !l!1at!d >BC. Choic! B: At!l!ctai i collap! of !g,!nt of l"ng. hi can l!ad to dypn!a and tachypn!a0 d!p!nding on th! d!gr!! of at!l!ctai. 6otop!rati1! at!l!ctai i a ,a/or ca"! of f!1!r. It ,ay b! d"! to ,"c" pl"g0 potop!rati1! pain0 d!cr!a!d ,obility and poor p"l,onary toil!t. h! diagnoi i ,ad! on a ch!t x-ray. Choic! D: A 7 can r!1!al that th!r! i a lo$ probability of a 6E. It i 1!ry "nli!ly to ha1! a 6E $ith lo$ probability 7 can. A 6E g!n!rally pr!!nt fro, fi1!-to-!1!n day aft!r "rg!ry. D!pit! prophylactic ,!a"r! to pr!1!nt it0 it till ca"! tho"and of d!ath in 9orth A,!rica !ach y!ar. Choic! E: A pn!",othorax can ca"! dypn!a and tachypn!a. In thi pati!nt0 th! ch!t x-ray do! not r!1!al any !1id!nc! of a pn!",othorax. A pn!",othorax on a ch!t x-ray $ill b! !aily r!cogni5!d. 8,all pn!",othorac! do not g!n!rally ca"! y,pto,. Ed"cational ob/!cti1!: ARD8 can pr!!nt $ith dypn!a0 tachypn!a and bilat!ral fl"ffy infiltrat! on a ch!t x-ray. It i a condition $h!r! hypox!,ia p!rit and it b!co,! diffic"lt to oxyg!nat! th! pati!nt.
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61
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 55: A 9-ye!-ol" "%.e&%c ' /!ee& #%&$ lo#-+!"e ,ee!3 ,c%l /% oe! $% !%+$& '%ll3 " .loo"y l "%c$!+e ,o! &$e l& &$!ee "y1 o! &$e l& "y3 $e $ $" "%/lo/%1 4e # "%+oe" #%&$ "%.e&e 'ell%& 8> ye! +o1 o! &$e l& ye!3 $e $ .ee o %l%1 4% 'o& !ece& $e'o+lo.% A8C # 821>1 4% &e'/e!&!e % 9?1O C (8>212 )3 /le % @@'%3 " .loo" /!e!e % 89>6'' 4+1 E'%&%o $o# !%+$&-%"e" l co+e&%o " ec!o% o, &$e !%+$& l &!.%&e #%&$ &e"e!e oe! &$e !%+$& '%ll!y %1 T$e!e % c$e'o% " /!o/&o% o, $% !%+$& eye1 CT c $o# o/c%,%c&%o o, &$e !%+$& '%ll!y %1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely c&%e o!+%'; A. B. C. D. E. . .
Rhi5op" p!ci! 8taphylococc" a"r!" 6!"do,ona a!r"ginoa Ha!,ophil" infl"!n5a! Morax!lla catarrhali Cryptococc" n!ofor,an Candida albican
Explanation:
hi pati!nt i ,ot li!ly "ff!ring fro, ,"cor,ycoi of th! no! and ,axillary in". h! ,ot co,,on !tiologic ag!nt i Rhi5op". 6oorly controll!d diab!t! ,!llit" pr!dipo! to thi di!a!. Lo$-grad! f!1!r0 bloody naal dicharg!0 naal cong!tion0 and in1ol1!,!nt of th! !y! $ith ch!,oi0 proptoi0 and diplopia ar! i,portant f!at"r!. In1ol1!d t"rbinat! oft!n b!co,! n!crotic. In1aion of local ti"! can l!ad to blindn!0 ca1!rno" in" thro,boi0 and co,a. If l!ft "ntr!at!d0 ,"cor,ycoi can l!ad to d!ath in day to $!!. #Choic! B% 8taphylococc" a"r!" i a co,,on ca"! of c!ll"liti. #Choic! C% 6!"do,ona i a ca"! of ,alignant otiti !xt!rna in diab!tic pati!nt it ,ay ca"! blac n!crotic l!ion in th! !ar. #Choic! D and E% H. Infl"!n5a and Morax!lla catarrhali ar! co,,on ca"! of bact!rial in"iti. h!! ""ally do not ca"! n!crotic inf!ction. #Choic! % Cryptococc" n!ofor,an ca"! ,!ningiti in i,,"noco,pro,i!d pati!nt. #Choic! C% Candida can ca"! thr"h and 1aginiti in diab!tic pati!nt. 9!crotic l!ion ar! "nco,,on. Ed"cational 4b/!cti1!: h! aociation b!t$!!n diab!t! ,!llit" and ,"cor,ycoi i fr!;"!ntly t!t!d on th! F8MLE. h! ,ot co,,on ca"! of ,"cor,ycoi i Rhi5op".
62
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 56: A 6>-ye!-ol" #o' co'e &o &$e e'e!+ecy "e/!&'e& "e &o ""e oe& o, ee!e /% % $e! le,& eye #%&$ .l!!e" %%o3 e3 " o'%&%+1 T$e y'/&o' .e+ ,e# '%&e +o3 #$%le $e # #&c$%+ 'o%e % e! .y &$e&e!1 4e! .loo" /!e!e % 80>?> '' 4+3 /le % @2'%3 !e/%!&%o !e 80'%3 " &e'/e!&!e % ?@10 1 E'%&%o !eel "ec!ee" %l c%&y1 4e! le,& eye //e! !e"3 #%&$ $y co!e3 $llo# &e!%o! c$'.e!3 " "%l&e"3 ,%e" //%l1 4e! le,& eye % &oy $!" &o &oc$1 W$& % &$e 'o& l%kely "%+o%; A. B. C. D. E.
6ri,ary op!n angl! gla"co,a Con/"ncti1iti Ac"t! angl! clo"r! gla"co,a Ant!rior "1!iti Corn!al abraion
Explanation:
Angl! clo"r! gla"co,a occ"r $ith clo"r! of a pr!-!xiting narro$ ant!rior cha,b!r angl!. It pr!do,inantly occ"r in p!opl! ag!d GG-)3 y!ar. It pr!!nt $ith an ac"t! on!t of !1!r! !y! pain and bl"rr!d 1iion aociat!d $ith na"!a and 1o,iting. It ""ally occ"r follo$ing p"pillary dilation0 $hich ,ay occ"r in dar!n!d ,o1i! th!at!r0 d"ring ti,! of tr!0 or d"! to dr"g inta!. Exa,ination r!1!al a r!d !y! $ith t!a,y corn!a and ,od!rat!ly dilat!d p"pil that i non r!acti1! to light. h! ant!rior cha,b!r i hallo$ $ith infla,,atory chang!. ono,!try r!1!al incr!a!d intraoc"lar pr!"r!. Intra1!no" ac!ta5ola,id! #$ith "b!;"!nt oral ad,initration% ,ay lo$!r th! intraoc"lar pr!"r!. 6!r,an!nt c"r! i off!r!d $ith la!r p!riph!ral iridoto,y. #Choic! A% 4p!n angl! gla"co,a ha an inidio" on!t0 $ith grad"al lo of p!riph!ral 1iion r!"lting in t"nn!l 1iion. 4th!r charact!ritic f!at"r! ar! p!rit!ntly incr!a!d intraoc"lar pr!"r! and pathologic c"pping of th! optic dic. #Choic! B% Con/"ncti1iti i charact!ri5!d by 1!ry ,ild pain. h! corn!a i cl!ar. 6"pilla i5! and r!pon! to light i nor,al. 7i"al ac"ity i not aff!ct!d. #Choic! D% F1!iti pr!!nt $ith ,od!rat! pain and bl"rr!d 1iion. Corn!a ,ay b! ha5y. h! ant!rior cha,b!r ho$ flar! and c!ll on lit la,p !xa,ination. h! p"pil i contrict!d $ith a poor light r!pon! #In ac"t! gla"co,a0 th! p"pil i dilat!d and i nonr!acti1! to light%. #Choic! E% Corn!al abraion pr!!nt $ith !1!r! pain and photophobia. h!r! i ""ally a hitory of tra",a to th! !y!. 8lit la,p !xa,ination $ith fl"or!c!in $ill r!1!al th! corn!al abraion. Ed"cational 4b/!cti1!: Angl! clo"r! gla"co,a occ"r pr!do,inantly in p!opl! ag!d GG-)3 y!ar. It pr!!nt $ith an ac"t! on!t of !1!r! !y! pain and bl"rr!d 1iion aociat!d $ith na"!a and 1o,iting. Exa,ination r!1!al a r!d !y! $ith t!a,y corn!a and ,od!rat!ly dilat!d p"pil that i non r!acti1! to light.
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63
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 57: A hich of th! follo$ing i th! ,ot appropriat! n!xt t!p in th! ,anag!,!nt of thi pati!nt A. B. C. D. E. . .
Li1!r biopy Bon! ,arro$ biopy Right "pp!r ;"adrant "ltrao"nd L",bar p"nct"r! C can of th! h!ad 6!riph!ral blood ,!ar H!,oglobin !l!ctrophor!i
Explanation:
hi pati!nt ha !1!ral ,!tabolic abnor,aliti! r!;"iring f"rth!r in1!tigation. H! ha a nor,ocytic #MC7 @ (G fl% h!,olytic an!,ia $ith an appropriat! bon! ,arro$ r!pon! #!1id!nc!d by th! high r!tic"locyt! co"nt%0 an incr!a!d indir!ct bilir"bin l!1!l0 thro,bocytop!nia and r!nal fail"r!. og!th!r th!! finding "gg!t a poibl! diagnoi of thro,botic thro,bocytop!nic p"rp"ra-h!,olytic "r!,ic yndro,! #6HF8%. Ab!nc! of f!1!r $a not!d in a r!c!nt ca! !ri! of pati!nt $ith 6-HF8. Ho$!1!r0 th! pati!nt alo ha a hitory of HI7 and h!patiti C0 both of $hich can ca"! thro,bocytop!nia and an!,ia of chronic di!a!. Both can alo ca"! r!nal fail"r! #HI7 focal !g,!ntal glo,!r"locl!roi: HC7 ,!,branoprolif!rati1! glo,!r"lon!phriti%0 and th! pati!nt+ A8 and AL !l!1ation co"ld b! d"! to chronic li1!r di!a! fro, HC7. A !y cl"! to th! diagnoi of 6-HF8 in thi pati!nt i hi r!tic"locytoi. A p!riph!ral ,!ar $ith 2= chitocyt! $o"ld b! 1irt"ally diagnotic of ,icroangiopathic h!,olytic an!,ia #MAHA%0 a co,pon!nt of H6-HFB. Ho$!1!r0 MAHA can alo 64
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* occ"r in DI and ,alignant hyp!rt!nion. Coag"lation t!t $o"ld h!lp to r"l! o"t DI. #DI pati!nt t!nd to bl!!d and ha1! abnor,al coag"lation t"di!. H6-HF8 pati!nt do not bl!!d d!pit! th!ir lo$ plat!l!t co"nt.% Malignant hyp!rt!nion ho"ld b! conid!r!d if th!r! i a hitory of hyp!rt!nion and !1id!nc! of hyp!rt!ni1! r!tinopathy on f"nd"copic !xa,. I,portantly0 HI7 pati!nt ar! at incr!a!d ri for H6. Ed"cational 4b/!cti1!: Fn!xplain!d h!,olytic an!,ia and thro,bocytop!nia in a pati!nt $ith r!nal fail"r! and n!"rologic y,pto, ho"ld rai! trong "picion for I6-HF8. HI7 incr!a! th! ri for H6. >itho"t pro,pt intit"tion of appropriat! th!rapy0 H6-HF8 pro1! l!thal in (3= of pati!nt. A high d!gr!! of clinical "picion i th" r!;"ir!d.
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65
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 58: A 5>-ye!-ol" #o' co'e &o &$e o,,%ce " co'/l% o, !%+$& $ol"e! /% #$%c$ !"%&e &o $e! $"1 S$e $ $" co+$ ,o! 'y #eek3 " ,eel <'o!e &%!e" &$ &$e l1= I ""%&%o3 $e! ,%+e! !e l#y #olle3 " $e o# ,%" %& "%,,%cl& &o #lk .ece $e! kee +%e #y1 S$e $ $" !$e'&o%" !&$!%&% ,o! &$e /& 8> ye! " % e" &o $%+ /% % $e! :o%& $o#ee!3 $e .el%ee &$& &$% /% % o& "e &o $e! !&$!%&%1 S$e &ke celeco%. ,o! !$e'&o%" !&$!%&%1 S$e "'%& &o 'ok%+ oe /ck o, c%+!e&&e "%ly ,o! &$e /& 25 ye!3 " &o "!%k%+ oe o"" .ee! ee!y %+$&1 All $e! ,'%ly 'e'.e! $e c!%//l%+ !$e'&o%" !&$!%&%1 4e! %&l %+ !e &.le1 S$e % ,e.!%le1 P$y%cl e'%&%o !eel "!oo/%+ o, &$e !%+$& eyel%" " '%o%1 W$& % &$e .e& e& &e/ % &$e '+e'e& o, &$% /&%e&; A. B. C. D. E. .
C can of h!ad and n!c ?-ray of th! ho"ld!r 8t!roid th!rapy Ch!t x-ray 9!r1! cond"ction t"dy El!ctro,yography
Explanation:
Fntil pro1!n oth!r$i!0 "p!ct l"ng canc!r in ,o!r $ho pr!!nt $ith Ho,!r+ yndro,! #i.!.0 partial ptoi0 ,ioi0 anhidroi%. 4th!r pr!!ntation of l"ng canc!r can incl"d! any of th! follo$ing: co"gh $ith bloody p"t",0 hortn! of br!ath0 ch!t pain0 lo of app!tit!0 and $!ight lo. Additional y,pto, that ,ay b! aociat!d $ith thi di!a! ar!: $!an!0 $allo$ing diffic"lty0 hoar!n! or changing 1oic!0 facial $!lling0 facial paralyi and !y!lid drooping. Mot l"ng canc!r ar! ca"!d by cigar!tt! ,oing. h! ,or! ignificant th! ,oing hitory th! gr!at!r th! ri of l"ng canc!r. 8!cond-hand ,o! ha alo b!!n ho$n to incr!a! th! ri. High l!1!l of poll"tion0 radiation0 and ab!to !xpo"r! ,ay alo incr!a! th! ri. In thi 1ign!tt!0 th!r! ar! ,any clinical cl"! to th! diagnoi of l"ng canc!r. In addition0 th! pati!nt+ ho"ld!r pain can b! attrib"t!d to th! dir!ct !xt!nion of th! l"ng canc!r0 a $!ll a in1ol1!,!nt of th! n!r1! of th! brachial pl!x" and y,path!tic tr"n. 8i,pl! ch!t x-ray ho"ld b! th! firt t!t in th! !1al"ation of thi pati!nt. #Choic! C% 8tarting t!roid i not r!ally th! b!t option. Altho"gh th! pati!nt ha a hitory of rh!",atoid arthriti0 h!r c"rr!nt co,plaint of pain do! not app!ar to b! r!lat!d to it. "rth!r,or!0 h!r /oint probl!, ,ight b! a part of hyp!rtrophic ot!oarthropathy. #Choic! D%h!r! i no hitory of tra",a th!r!for!0 obtaining a ho"ld!r x-ray i not th! b!t n!xt t!p in thi pati!nt+ ,anag!,!nt. #Choic! E and % hi i not a n!r1! di!a!0 o n!r1! cond"ction and EM4 ho"ld not b! "!d in th! ,anag!,!nt of thi pati!nt. Ed"cational 4b/!cti1!: Fntil pro1!n oth!r$i!0 "p!ct l"ng canc!r in ,o!r $ho pr!!nt $ith Ho,!r+ yndro,! #i.!.0 partial ptoi0 ,ioi0 anhidroi%. 8i,pl! ch!t x-ray ho"ld b! th! firt t!t in pati!nt $ith "p!ct!d l"ng canc!r.
66
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 59: A 2@-ye!-ol" ' % .!o+$& &o &$e e'e!+ecy !oo' .ece o, .lck #%"o# /%"e! .%&e o $% le,& ,o!e!'1 4e # cle%+ $% +!+e #$%le &$% $//ee"1 4e $ ee!e /% & &$e %&e o, &$e .%&e3 lo+ #%&$ +ee!l%e" ."o'%l "%co',o!&1 4e $ o o&$e! 'e"%cl /!o.le'1 4e "oe o& e &o.cco3 lco$ol3 o! "!+1 4e $ o ko# "!+ lle!+%e1 4% &e'/e!&!e % 915> (?? )3 .loo" /!e!e % 88>6@'' 4+3 /le % @@'%3 " !e/%!&%o !e 86'%1 4e % e!y %o &o ko# &$e e,,ec& o, .lck #%"o# /%"e! .%&e1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& //!o/!%&e e& &e/ % '+e'e&; A. B. C. D. E.
Calci", gl"conat! Dapon! 6!nicillin Rifa,pin 8t!roid
Explanation:
Blac $ido$ pid!r ar! ""ally fo"nd in $ar, part of th! F8A. h! pid!r got th! na,! d"! to th! b!li!f that th! f!,al! pid!r ill th! ,al! aft!r ,ating. h!! pid!r ""ally do not bit! h",an0 "nl! pro1o!d. h! toxin prod"c!d by th! blac $ido$ aff!ct th! n!r1o" yt!,. 9ot all bit! l!ad to !1!r! r!action. 8o,! bit! go "nnotic!d. 4th!r bit! ""ally l!ad to !1!r! pain at th! it!. Aft!r a $hil!0 th! bit! ,ar ho$ ign of infla,,ation along $ith tr!,or0 ,"cl! $!an!0 abdo,inal pain0 na"!a0 and 1o,iting. h! abdo,inal pain ,ay ,i,ic pancr!atiti or app!ndiciti. h! abdo,!n ,ay ha1! boardli! rigidity b"t i not t!nd!r to palpation. r!at,!nt incl"d! th! follo$ing t!p: N Baic or ad1anc!d lif! "pport. N h! it! ho"ld b! inp!ct!d and cl!an!d. N !tan" i,,"ni5ation ho"ld b! "pdat!d. N Hyp!rt!ni1! !piod! r!lat!d to th! !n1!no,ation ,ay r!;"ir! tr!at,!nt $ith nitropr"id!. O Abdo,inal cra,p ar! b!t tr!at!d $ith calci", gl"conat!. O Dia5!pa, or dantrol!n! can b! "!d to all!1iat! ,"cl! pa,. #Choic! B% B!ca"! of it l!"ocyt! inhibitory prop!rti!0 dapon! i "!d to r!d"c! th! !xt!nt of local n!croi in pati!nt $ith bro$n r!cl"! pid!r bit!. Ed"cational 4b/!cti1!: 2. Ac"t! abdo,!n i a f!at"r! of blac $ido$ pid!r bit! and i b!t tr!at!d $ith a co,bination of calci", gl"conat! and ,"cl! r!laxant. *. Bro$n r!cl"! pid!r bit! prod"c! an !xt!ni1! locali5!d in n!croi r!!,bling a pyod!r,a gangr!no",. Dapon! i "!d to r!d"c! th! !xt!nt of local n!croi in pati!nt $ho ha1! b!!n cr!!n!d for gl"co!-'-phophat! d!hydrog!na! #'6D% d!fici!ncy.
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67
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 60: A 22-ye!-ol" Cc% 'le colle+e &"e& /!ee& &o $% /!%'!y c!e /$y%c% co'/l%%+ o, &#o-"y $%&o!y o, !%+$& //e! ."o'%l /% " <o& ,eel%+ #ell1= 4e lo "'%& &o $%+ lly "!k !%e3 ,eel%+ ,&%+e" " o!e%c3 " "eelo/%+ ""e e!%o &o c%+!e&&e 'ok%+1 4e !e&!e" ,!o' &!%/ &o Me%co #%&$ $% ,'%ly //!o%'&ely &$!ee #eek +o1 4% %&e! $ %'%l! co'/l%& .& $ o& ye& o+$& 'e"%cl &!e&'e&1 4e % o& &k%+ y 'e"%c&%o " $ o ko# "!+ lle!+%e1 4e "oe o& 'oke c%+!e&&e " "!%k .ee! /!%'!%ly o oc%l occ%o1 P$y%cl e'%&%o !eel yello# cle!3 !%+$& //e! G"!& &e"e!e3 " $e/&o'e+ly1 To&l .%l%!.% % 'e!e" & 61> '+"L1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely ce o, $e/&%&% % &$% /&%e&; A. B. C. D. E.
H!patiti D H!patiti B H!patiti C H!patiti A Inf!ctio" ,onon"cl!oi
Explanation:
h! clinical pict"r! of 1iral h!patiti can b! di1id!d into thr!! pha!: th! prodro,al pha!0 th! ict!ric pha!0 and th! con1al!c!nt pha!. i1!n thi pati!nt+ /a"ndic! and $or!ning prodro,al y,pto,0 h! i conid!r!d to b! in th! ict!ric pha! of ac"t! h!patiti. Inf!ction $ith th! h!patiti A 1ir" i trongly "gg!t!d by hi r!c!nt tra1!l to an !nd!,ic co"ntry and hi it!r+ i,ilar clinical co,plaint. h! pathog!n r!ponibl! for h!patiti A i an R9A picorna1ir" $ith an a1!rag! inc"bation p!riod of <3 day. ran,iion occ"r thro"gh th! f!cal-oral ro"t! and i co,,on in ar!a $ith o1!rcro$ding and poor anitation. 4"tbr!a fr!;"!ntly r!"lt fro, conta,inat!d $at!r or food. 4n!t i ac"t!0 and y,pto, can incl"d! ,alai!0 fatig"!0 anor!xia0 na"!a0 1o,iting0 ,ild abdo,inal pain0 and an a1!rion to ,oing. H!pato,!galy i co,,only !!n. A8 and AL pi! !arly in th! illn!0 follo$!d by incr!a! in bilir"bin and alalin! phophata!. ort"nat!ly0 h!patiti A inf!ction i a !lf-li,iting di!a! and do! not progr! to chronic h!patiti0 cirrhoi0 or h!patoc!ll"lar carcino,a. h! ,ortality rat! i l! than 3.*=. altho"gh a ignificantly prolong!d prothro,bin ti,! corr!lat! $ith incr!a!d ,ortality. r!at,!nt of h!patiti A inf!ction i larg!ly "pporti1!0 $ith co,pl!t! r!co1!ry !xp!ct!d in <-' $!!. Clo! contact of indi1id"al $ith h!patiti A ho"ld pro,ptly b! gi1!n i,,"n! glob"lin. 6!opl! conid!r!d at high ri #!.g.0 tho! li1ing in or tra1!ling to !nd!,ic ar!a0 tho! $ith chronic li1!r di!a! or clothing-factor diord!r0 ,!n $ho ha1! !x $ith ,!n% ho"ld b! gi1!n th! h!patiti A 1accin! a prophylaxi. #Choic! B% H!patiti B i a D9A 1ir" $ith an inc"bation p!riod of <32(3 day. 4n!t i typically inidio"0 and tran,iion can occ"r !x"ally0 par!nt!rally0 or 1!rtically. Chronic h!patiti d!1!lop in 2*= of i,,"noco,p!t!nt ad"lt and 3= of n!$born. h!! chronic carri!r of HB7 ar! at ignificant ri of d!1!loping cirrhoi and 68
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* h!patoc!ll"lar carcino,a. R!co,binant 1accin! and h!patiti B i,,"n! glob"lin ar! th! a1ailabl! pr!1!ntati1! ,!a"r!. #Choic! C% H!patiti C i an R9A 1ir" $ith an a1!rag! inc"bation p!riod of &3-G3 day. Clinical illn! i ,ild and pati!nt ar! oft!n ay,pto,atic. Inf!ction $ith h!patiti C 1ir" pri,arily occ"r par!nt!rally0 b"t !x"al and 1!rtical tran,iion ar! alo poibl!. Chronic h!patiti d!1!lop in (3= of pati!nt0 $ho ar! th!n at incr!a!d ri of cirrhoi or h!patoc!ll"lar carcino,a. 9o 1accin! or i,,"noglob"lin ar! a1ailabl!0 tho"gh tr!at,!nt $ith int!rf!ron and riba1irin ""ally lo$ di!a! progr!ion. Clinically ignificant ac"t! h!patiti fro, h!patiti C inf!ction i 1!ry rar!. #Choic! A% H!patiti D i an inco,pl!t! R9A 1ir" that ca"! h!patiti only in aociation $ith h!patiti B inf!ction. It i tran,itt!d by p!rc"tan!o"0 !x"al0 and p!rinatal ro"t!. 8"p!rinf!ction $ith HD7 in a pati!nt $ith chronic h!patiti B can r!"lt in f"l,inant h!patiti or !1!r! chronic h!patiti that ;"icly progr!! to cirrhoi. 7accination againt h!patiti B i th! b!t ,!an of pr!1!nting inf!ction $ith h!patiti D. #Choic! E% Inf!ctio" ,onon"cl!oi can l!ad to h!patiti in adol!c!nt and yo"ng ad"lt. 8ign and y,pto, typically incl"d! or! throat0 f!1!r0 ly,phad!nopathy0 rah0 and pl!no,!galy. Ed"cational 4b/!cti1!: Epid!,iological diff!r!nc! #!.g.0 inc"bation p!riod0 ro"t! of tran,iion0 ri factor% off!r o,! of th! b!t ,!an of id!ntifying th! 1ir" r!ponibl! for a pati!nt+ h!patiti. Confir,ation can b! !tablih!d $ith !rological t!ting.
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69
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 61: A 92-ye!-ol" ,e'le % .!o+$& &o &$e cl%%c .y $e! $." .ece $e .el%ee $e % 'l%+e!e! " % <:& .e%+ "%,,%cl&1= So'e&%'e3 $e //e! co,e" " "%o!%e&e"1 Oe! &$e /& ye! $e $ co'/l%e" o, %l lo3 eye /% " %.%l%&y &o "o y $oe$ol" c$o!e1 T#o 'o&$ +o3 $e cl%'e" &o $e lo& co&!ol o, $e! .l""e!1 I&e!e&%+ly3 $e % <$e! o!'l el,= #$e %& % &%'e &o +o ,o! ''e! &!%/1 T$e #%,e %%& &$& $e "oe o& "e!&" #$& % $//e%+ &o $e!3 " "" &$& $e occ%olly loe &$e .%l%&y &o 'oe $e! !%+$& $"1 T$e /$y%cl e'%&%o % .%clly o!'l1 T$e /&%e& //e!3 le!&3 o!%e&e"3 " % % o "%&!e1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& //!o/!%&e e& &e/ % '+e'e&; A. B. C. D. E. .
MRI of th! brain L",bar p"nct"r! ono,!try 8!r", i,,"noglob"lin 9!r1! cond"ction t"di! R!f!r to pychiatry
Explanation:
8"p!ct ,"ltipl! cl!roi #M8% in a f!,al! $ho ha r!c"rr!nt attac of focal n!"rologic dyf"nction that occ"r at non- pr!dictabl! ti,! int!r1al. h! ag! of on!t i ""ally b!t$!!n th! third and th! fo"rth d!cad!. h! pathology in1ol1! d!,y!lination of focal r!gion in th! $hit! ,att!r of th! brain0 $ith a prop!nity to in1ol1! th! p!ri1!ntric"lar and "bpial $hit! ,att!r of th! c!r!br",0 th! optic n!r1!0 brain t!, and pinal cord. h! MRI i th! diagnotic t!t of choic! for id!nti2iing d!,y!linating l!ion. 7i"al0 a"ditory and o,ato!nory !1o!d r!pon! t!t ar! of 1al"! in id!ntifying il!nt l!ion. #Choic! B% Abnor,aliti! in th! c!r!bropinal fl"id ,ay b! !!n $ith M8. 8"ch abnor,al C8 finding incl"d! oligoclonal band0 pl!ocytoi0 !l!1at!d Ig or ,y!lin baic prot!in and ,ild ly,phocytoi. Ho$!1!r0 th!! finding ar! not 1!ry conit!nt0 and ar! not diagnotic. #Choic! C% ono,!try i ""ally don! to ,!a"r! th! pr!"r! in th! oc"lar cha,b!r to a! th! pr!!nc! of gla"co,a. #Choic! D% Chang! in !r", i,,"noglob"lin occ"r in M80 b"t ar! not p!cific. Analyi of ly,phocyt! "bpop"lation ,ay d!,ontrat! r!d"c!d n",b!r of c!ll $ith th! "ppr!or ph!notyp! d"ring or pr!c!ding attac. #Choic! E% 9!r1! cond"ction t"di! do not play a rol! in th! diagnoi of M80 b"t th!! can b! "!d to id!ntify th! location of th! c"rr!nt n!"rologic d!ficit in th! !xtr!,iti!0 a $!ll a clinically il!nt l!ion. Frodyna,ic t"di! oft!n aid in th! !1al"ation and ,anag!,!nt of bladd!r y,pto,. #Choic! % D!pit! th! h"band+ b!li!f that th! pati!nt i ,aling!ring0 th! pati!nt+ hitory i "gg!ti1! of a n!"rologic diord!r #M8% $hich $arrant f"rth!r !1al"ation $ith n!"roi,aging t"di!. A pychiatry r!f!rral i not $arrant!d at thi ti,!. Ed"cational 4b/!cti1!: M"ltipl! cl!roi i b!t diagno!d $ith MRI. h! MRI ho$ $hit! ,att!r di!a!0 $hich i 1!ry charact!ritic for ,"ltipl! cl!roi. 70
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 62: A /$!'ce&%cl co'/y !ee!c$e! % #o!k%+ o "!+ 3 y J /!o/oe" ,o! &$e &!e&'e& o, "%.e&e 'ell%&1 4e elec& +!o/ o, 9>> "%.e&%c /&%e& ,!o' co&y $o/%&l % cko1 TN1 4e !"o'ly "%%"e &$e' %&o 9 +!o/ o, 8>> /&%e& ec$ (3 . J c)1 !o/ !ece%e "!+ 3 +!o/ . !ece%e "!+ y3 " +!o/ c !ece%e "!+ 1 4e ,ollo# &$ee +!o/ /!o/ec&%ely,o!6 'o&$ " &.l&e &$e ,ollo#%+ !el& % .elo# +!/$1 Be" o &$ee !el&3 #$%c$ o, &$e ,ollo#%+ &&e'e& % co!!ec&;
A. hi t"dy i in1alid b!ca"! th! a,pl! !l!ction i i,prop!r B. Dr"g x i th! ,ot pot!nt a,ongt th! thr!! dr"g C. h!r! i no tatitically ignificant diff!r!nc! b!t$!!n th! !ff!ct of dr"g x P 5 D. Dr"g 5 ha th! $id!t rang! of !ff!ct #i.!. it i !ff!cti1! in o,! pati!nt P not !ff!cti1! in oth!r% E. Dr"g y $ill r!"lt in a ignificant incr!a! in ,ortality in diab!tic pati!nt if "!d on a r!g"lar bai Explanation:
Confid!nc! int!r1al #Cl% of th! ,!an i calc"lat!d by th! follo$ing for,"la: Cl #,!an%@ ,!an Q tandard cor! #5% tandard !rror of ,!an #8E%. 8tandard !rror of ,!an #8E% i calc"lat!d by di1iding th! tandard d!1iation #8D% by th! ;"ar! root of th! a,pl! i5! #9%. H!nc!0 a th! 8D incr!a!0 th! 8E and Cl alo incr!a!. A 9 incr!a!0 8E d!cr!a!. In th! abo1!,!ntion!d t"dy0 th! Cl for gro"p a i 3.( #(G.& ,in" (&.'@ 3.(%. 8i,ilarly0 th! Cl for gro"p b i 3.&0 and that of gro"p c i 2.<*. #9ot! that th! Cl i gi1!n in th! tabl! and yo" can a1! ti,! fro, calc"lating th! Cl for all < gro"p if yo" loo into all th! data car!f"lly. So" can calc"lat! th! Cl for all < gro"p "ing 8D0 90 and ,!an 1al"!0 b"t it $ill b! a $at! of ti,! d"ring th! !xa,TTT% A larg!r confid!nc! int!r1al ,!an that th!r! i a $id!r rang! of poibl! !ff!ct. A ,all!r confid!nc! int!r1al ,!an that th!r! i a narro$!r rang! of poibl! !ff!ct. 8inc! dr"g 5 ha th! $id!t confid!nc! int!r1al0 it $ill ha1! th! $id!t rang! of poibl! !ff!ct. #Choic! A% h! r!!arch!r ha !l!ct!d all th! pati!nt $ith diab!t! and ha di1id!d th!, rando,ly0 ,aing thi a 1alid t"dy. #Choic! C% If th! confid!nc! int!r1al of diff!r!nt gro"p o1!rlap0 th!n th! gro"p ar! conid!r!d to ha1! no tatitically ignificant diff!r!nc!. 8inc! confid!nc! int!r1al of gro"p a and c ar! non-
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71
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* o1!rlapping0 th!r! i a tatitically ignificant diff!r!nc! b!t$!!n th!! gro"p. #Choic! B and E%hi t"dy do! not gi1! any infor,ation abo"t th! dr"g+ pot!ncy or th! r!d"ction in ,ortality. Dr"g pot!nci! ar! d!t!r,in!d by log do! r!pon! c"r1!. Co,,!nt abo"t ,ortality cannot b! ,ad!0 a ,ortality rat! ar! not ,!ntion!d. Ed"cational 4b/!cti1!: Confid!nc! int!r1al #Cl% of th! ,!an i calc"lat!d by th! follo$ing for,"la. Cl #,!an% @ ,!an Q tandard cor! #5% tandard !rror of ,!an #8E%.
72
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 63: A 50-ye!-ol" A,!%c A'e!%c 'le /!ee& &o &$e R #%&$ ec!c%&%+ !%+$& ,lk /% !"%&%+ &o $% &e&%cle ,o! &$e /& 2 $o!1 4e "ec!%.e &$% /% 8>8>1 4e lo co'/l% o, o'%&%+1 4% 'e"%cl $%&o!y % %+%,%c& ,o! +o&3 co!o!y !&e!y "%ee3 4I73 4e/&%&% C3 c$!o%c !el %,,%c%ecy ,!o' 4I73 " 6PD "e,%c%ecy1 P&%e& $ o& .ee co'/l%& #%&$ $% 'e"%c&%o ece/& %&'% C1 O /$y%cl e'%&%o3 $e % e&!e'ely !e&le " % o.%o /%1 A."o'%l e'%&%o % o!'l ece/& ,o! '%l" +!"%+ +e%&l% !e o!'l1 Pl% -!y ."o'e $o# .!%+$& !"%o/Ge !el clcl%1 T$e 'o& l%kely ce ,o! &$e "eelo/'e& o, &$% co"%&%o %; A. B. C. D. E.
o"t HI7 H!patiti C '6D d!fici!ncy 7ita,in C
Explanation:
High do! of 1ita,in C #2 g,% can pr!cipitat! r!nal calc"li by incr!aing "rinary oxalat! !xcr!tion. It pr!dipo! to for,ation of calci", oxalat! ton!. E1!n tho"gh th! data i t!ntati1!0 pati!nt $ith a pr!dipoition to for, oxalat! ton! or tho! on h!,odialyi ho"ld a1oid !xc!i1! "! of 1ita,in C. o"t can ca"! "ric acid ton! b"t th!y ar! radiol"c!nt a oppo!d to th! radiopa;"! ton! in thi ca!. HI7 do! not pr!dipo! to for,ation of r!nal calc"li altho"gh indina1ir #anti-r!tro1iral dr"g% can ca"! n!phrolithiai. '6D d!fici!ncy and H!patiti C ha1! no r!lation to r!nal calc"li. High do! of 7ita,in C can ind"c! h!,olyi in pati!nt $ith '6D d!fici!ncy. Ed"cational 4b/!cti1!: Exc!i1! "! of 1ita,in C in pati!nt $ith r!nal in"ffi!ncy can ca"! oxalat! ton!.
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73
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 64: A >-ye!-ol" Cc% 'le /!ee& &o yo! o,,%ce ,o! el&%o o, k% le%o o $% ,o!e$e"1 O /$y%cl e' yo ,%" &$& &$ee //le $e " //e! &e&!e .y /l/&%o1 T$e le%o !e %ll&!&e" % &$e l%"e .elo#1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely "%+o% % &$% /&%e&;
A. B. C. D. E.
6oriai 8!borrh!ic !ratoi Actinic !ratoi Atopic d!r,atiti 6ityriai ro!a
Explanation:
h! l!ion on th! i,ag! abo1! r!pr!!nt actinic !rato! #AK%. AK ar! claically d!crib!d a !ryth!,ato" pap"l! $ith a c!ntral cal! d"! to hyp!r!ratoi. A Uandpap!r-li!V t!xt"r! on palpation of th! aff!ct!d ar!a i typical for thi condition. h! l!ion ar! ,all and flat at firt0 b"t ,ay !nlarg! and b!co,! !l!1at!d. F"ally th!ir i5! do! not !xc!!d 23,, in dia,!t!r. Hyp!r!ratoi in "ch l!ion ,ay b!co,! pro,in!nt and t"rn into Uc"tan!o" hornV. Actinic !rato! d!1!lop in g!n!tically pr!dipo!d indi1id"al &3-'3 y!ar of ag! "nd!r th! infl"!nc! of !xc!i1! "n !xpo"r!. h! ,ot co,,only aff!ct!d ar!a ar! th! fac!0 !ar0 calp and th! dora of th! ar, and hand0 b"t any oth!r chronically "n-!xpo!d it! #l!g0 bac0 "pp!r ch!t% can b! in1ol1!d. 4n light ,icrocopy0 aff!ct!d ar!a ho$ acanthoi #thic!ning of th! !pid!r,i%0 para!ratoi #r!t!ntion of n"cl!i in th! trat", corn!",%0 dy!ratoi #abnor,al !ratini5ation%0 and hyp!r!ratoi #thic!ning of trat", corn!",%. K!ratinocyt! diplay 1ario" d!gr!! of atypia. Mito! and an infla,,atory infiltrat! ar! pr!!nt. Actinic !ratoi i r!gard!d a !ith!r a pr!,alignant condition or a carcino,a in it"0 b"t l! than 2= of AK $ill !1ol1! into fran ;"a,o" c!ll carcino,a. #Choic! A% 6oriai pr!!nt $ith $!ll-circ",crib!d rai!d pap"l! and pla;"! co1!r!d $ith a thic il1!ry cal!. h! l!ion ar! locat!d on th! calp0 tr"n and !xt!nor ar!a of !xtr!,iti! #Elbo$ and n!!%. #Choic! B% 8!borrh!ic !rato! occ"r in !ld!rly indi1id"al and pr!!nt $ith Ut"c-onV0 d!!ply pig,!nt!d or fl!h color!d l!ion $ith 1!l1!ty or Ugr!ayV "rfac!. #Choic! D% Atopic d!r,atiti i a typ! I #i,,!diat!% hyp!r!niti1ity r!action. Ac"t! atopic d!r,atiti ,anif!t $ith highly pr"ritic pap"l!0 1!icl! and pla;"!. Light ,icrocopy d!,ontrat! pongioi #!d!,a of th! !pid!r,i%. #Choic! E% h! firt y,pto, of pityriai ro!a i pin or bro$n caly pla;"! $ith c!ntral cl!aring and a collar!tt! of cal! #h!rald patch% on th! tr"n0 n!c or !xtr!,iti!. It i follo$!d by d!1!lop,!nt of 74
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* ,ac"lopap"lar rah claically in a UChrit,a tr!!V patt!rn along th! in t!nion lin!. Ed"cational 4b/!cti1!: Actinic !rato! d!1!lop in pr!dipo!d indi1id"al on chronically "n-!xpo!d ar!a of th! in. h! l!ion conit of !ryth!,ato" pap"l! $ith a c!ntral cal! and a Uandpap!r-li!V t!xt"r!. Actinic !rato! can con1!rt to ;"a,o" c!ll carcino,a in approxi,at!ly 2= of ca!.
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75
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 65: A 02-ye!-ol" 'le /!ee& #%&$ 2-ye! $%&o!y o, $e!&.!1 T$e $e!&.! occ! ,&e! $ey 'el " #$%le /%e1 Oe!&%'e3 $% y'/&o' $e .ee %c!e%+ % ee!%&y " ,!eGecy1 4% y'/&o' e" &o .e lle%&e" #%&$ &$e e o, oe!-&$e-co&e! &c%"1 B& &$ee $e .eco'e %e,,ec&%e % &$e /& &#o 'o&$1 4e lo co'/l% o, e/%+&!%c /% " occ%ol o'%&%+3 .o&$ o, !ece& oe&3 e/ec%lly % &$e 'o!%+1 4e "e%e "y/$+% o! o"yo/$+%1 4e e& :k ,oo" " "!%k &#o c/ o, co,,ee "%ly1 4e !e+l!ly "!%k +!/e .!"y " 'oke 8 /ck o, c%+!e&&e"y1 A."o'%l e'%&%o $o# e/%+&!%c &e"e!e1 A."o'%l l&!o" % !e'!k.le1 Te& o, &$e &ool ,o! occl& .loo" % e+&%e1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& //!o/!%&e e& &e/ % '+e'e&; A. B. C. D. E.
r!at,!nt $ith ranitidin! Fpp!r I !ndocopy Bari", $allo$ Mano,!tric t"di! R!a"ranc!
Explanation:
hi pati!nt+ *-y!ar hitory of h!artb"rn i y!$ "gg!ti1! of r!fl"x !ophagiti ho$!1!r0 th! r!c!nt on!t of n!$ y,pto, alo "gg!t anoth!r probl!,0 "ch a Barr!tt+ !ophag"0 p!ptic "lc!r di!a!0 gatriti0 or !1!n a t",or. 4f th! lit!d t"di!0 !ndocopy can pro1id! th! ,ot infor,ation in th! $or-"p of any of th!! diagno!. #Choic! A% h! g!n!rally r!co,,!nd!d initial tr!at,!nt for pati!nt $ith "nco,plicat!d gatro!ophag!al r!fl"x di!a! i a trial of proton p",p inhibitor th!rapy. H* r!c!ptor antagonit ar! no long!r r!co,,!nd!d a th! firt lin! of th!rapy for grad! * or $or! !ophagiti. 6ati!nt ho"ld b! ad1i!d abo"t anti-r!fl"x ,!a"r! #!.g.0 topping ,oing0 $!ight lo0 !l!1ating th! h!ad of th! b!d0 ,all ,!al0 and ,odifying th! !ating habit%. #Choic! C% 6ro1id!d that th! pati!nt do! not ha1! dyphagia0 !ndocopy can b! p!rfor,!d $itho"t a pr!c!ding contrat t"dy. #Choic! D% If !ndocopy i n!gati1!0 ,ano,!try ,ay b! indicat!d. Ed"cational 4b/!cti1!: R!cogni5! $h!n to ord!r "pp!r !ndocopy in th! ,anag!,!nt of gatro!ophag!al r!fl"x di!a!. h! follo$ing ar! o,! alar, ignal: 2. 9a"!a1o,iting *. >!ight lo an!,ia or ,!l!nablood in th! tool <. Long d"ration of y,pto, #2-* y!ar%0 !p!cially in Ca"caian ,al! &G y!ar old &. ail"r! to r!pond to proton p",p inhibitor
76
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 66: A <(-y!ar-old f!,al! pr!!nt to th! phyician b!ca"! of a t$o-$!! hitory of $or!ning h!adach! and lo$-grad! f!1!r. 8h! d!ni! any $!an! or !nory lo. 8h! ha had ignificant $!ight lo o1!r th! lat ix ,onth. H!r p"l! i (3,in0 blood pr!"r! i 22G)3 ,, Hg0 r!piration ar! 2&,in0 and t!,p!rat"r! i <(.2 C #233.G %. 8h! app!ar cach!ctic. H!r n!c i tiff and th!r! i c!r1ical ly,phad!nopathy pr!!nt. 4ropharyng!al !xa, r!1!al thr"h. h! n!"rological !xa,ination i non2ocal0 and f"nd"copy i $ithin nor,al li,it. Ch!t i cl!ar to a"c"ltation. L",bar p"nct"r! and C8 !xa,ination ho$ th! follo$ing r!"lt: 4p!ning pr!"r! *G3 c, H*3 l"co! && ,gdL 6rot!in 2*3 ,gdL RBC non! >BC G3,,J C8 c"lt"r! gro$ !ncap"lat!d y!at. >hich of th! follo$ing i th! ,ot appropriat! n!xt t!p in th! ,anag!,!nt of thi pati!nt A. B. C. D. E.
A,phot!ricin pl" fl"cytoin! Intra1!no" itracona5ol! 4ral gri!of"l1in 4ral "lfadia5in!pyri,!tha,in! HI7 t!ting and anti r!tro1iral th!rapy
Explanation:
hi pati!nt+ clinical f!at"r! and 48E t"di! highly "gg!t "bac"t! cryptococcal ,!ningiti and "nd!rlying HI7 inf!ction. Cryptococc" i an !ncap"lat!d y!at that co,,only ca"! ,!ningiti in HI7 pati!nt. "b!rc"loi i alo an i,portant ca"! of "bac"t! ,!ningiti in th!! pati!nt. Initial ind"ction th!rapy for c!ntral n!r1o" yt!, cryptococcal inf!ction in AID8 pati!nt i I7 a,phot!ricin B pl" oral fl"cytoin!. >h!n th!r! i clinical i,pro1!,!nt $ith ind"ction th!rapy a,phot!ricin and fl"cytoin! ar! dicontin"!d and oral fl"cona5ol! i tart!d a ,aint!nanc! th!rapy. #Choic! B% Itracona5ol! can b! "!d a a ,aint!nanc! th!rapy for Hitopla,a cap"lat", ,!ningiti. H. cap"lat", ,!ningiti i alo initially tr!at!d $ith a,phot!ricin. #Choic! C% 4ral gri!of"l1in i not appropriat! to tr!at cryptococcal ,!ningiti. #Choic! D% 4ral "lfadia5in!-pyri,!tha,in! i "!d to tr!at toxopla,oi0 $hich ""ally ,anif!t a !nc!phaliti in HI7 pati!nt. In toxopla,a !nc!phaliti0 C can $ith contrat ho$ ,"ltipl! hypod!n!0 ring-!nhancing l!ion. #Choic! E% HI7 t!ting and0 if poiti1!0 HAAR th!rapy i indicat!d in thi pati!nt b"t ho"ld not d!lay antif"ngal tr!at,!nt. Ed"cational 4b/!cti1!: I7 a,phot!ricin pl" fl"cytoin! i th! antibiotic r!gi,!n of choic! for c!ntral n!r1o" yt!, cryptococcal inf!ction in AID8 pati!nt.
__________________________________________________________
77
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 67: A &&-y!ar-old ob!! f!,al! "nd!rgo! an op!n chol!cyt!cto,y for a co,plicat!d ac"t! chol!cytiti. 4n h!r third pot-op!rati1! day0 h!r t!,p!rat"r! i <'.) C #(.* %0 blood pr!"r! i 223(3,, Hg and p"l! i *,in. H!r art!rial blood ga ho$ th! follo$ing: Blood pH ).*( 6a4* '* ,,Hg 6aC4* G&,,Hg H4<<3,E;L >hat i th! ,ot li!ly ca"! of acidoi in thi pati!nt A. B. C. D. E.
Al1!olar hypo1!ntilation Ac"t! p"l,onary !,boli, At!l!ctai 6"l,onary !d!,a 6l!"ral !ff"ion
Explanation:
h! pati!nt d!crib!d ha a r!piratory acidoi !1id!nc!d by h!r art!rial blood ga 1al"! that ho$ a d!cr!a!d pH #c ).
78
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 68: A 52-ye!-ol" A,!%c-A'e!%c 'le co'e ,o! !e+l! $el&$ c$eck-/1 4e % c$!o%c 'oke! " $ .ee "!%k%+ .o& 2 .ee!"y ,o! &$e /& 8> ye!1 4e lo "!%k .o&; c/ o, co,,ee"y1 4e # "%+oe" #%&$ "%.e&e 5y! +o " &ke 'e&,o!'% ,o! %&1 O e'%&%o3 $e $ Bo"y M I"e (BMI) o, 2? " BP 89>@> '' 4+1 4% !"o' .loo" +! % 8?> '+"l1 4% el"e! .!o&$e! "%e" o, /c!e&%c cce! & +e o, 5@ " $e % #o!!%e" &$& $e '%+$& lo +e& /c!e&%c cce!1 W$%c$ o, &$e ,ollo#%+ %&e!e&%o #ol" "ec!ee $% !%k o, /c!e&%c cce! &$e 'o&; A. B. C. D. E.
8top th! alcohol inta!. 8top ,oing. 8top th! coff!! inta!. 8top ,!tfor,in. Achi!1! b!tt!r control of blood "gar $ith in"lin.
Explanation:
6ancr!atic canc!r i a highly ,alignant canc!r ,aing it fifth ,ot co,,on ca"! of canc!r r!lat!d ,ortality. It r!"lt in d!ath in (= of afflict!d indi1id"al #(= fatality rat!%. Ri factor for pancr!atic canc!r ar!: 2. Mal! !x. *. Incr!aing ag! #G3 y!ar%. <. Blac rac!. &. Cigar!tt! ,oing: It i th! ,ot conit!nt ri factor. 6ancr!atic canc!r i *-< ti,! ,or! li!ly in h!a1y ,o!r than in non,o!r. G. Chronic pancr!atiti. '. Long-tanding diab!t!. ). 4b!ity. (. a,ilial pancr!atiti. . 6ancr!atic canc!r in a clo! r!lati1!. h! follo$ing ar! not ri factor for pancr!atic canc!r: 2. Alcohol con",ption. *. all ton! <. Coff!! inta!. #Choic! A and C% Alcohol inta! and coff!! inta! ar! not ri factor for pancr!atic canc!r. #Choic! D% M!tfor,in i not aociat!d $ith pancr!atic canc!r. #Choic! E% Long tanding diab!t! i a ri factor for pancr!atic canc!r. Ho$!1!r0 thi pati!nt ha b!!n diagno!d $ith diab!t! G y!ar ago and th! b!n!fit of ,oing c!ation in pr!1!ntion of pancr!atic canc!r o"t$!igh th! b!n!fit of "gar control. Ed"cational 4b/!cti1!: Cigar!tt! ,oing i th! ,ot conit!nt r!1!ribl! ri factor for pancr!atic canc!r.
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79
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 69: A @9-ye!-ol" #o' /!ee& #%&$ 8-ye! $%&o!y o, /!o+!e%ely ee!e c!'/y ."o'%l /% ,&e! e&%+1 S$e $ &!&e" o%"%+ ,oo" .ece o, &$e /%1 T$e /% % o,&e oc%&e" #%&$ .lo&%+3 e3 o'%&%+3 " "%!!$e1 Rece&ly3 $e! &ool $e .ee .lky ,o'y3 " +!ey1 S$e $ $" 85k+ (99l.) #e%+$& lo oe! &$e /& ye!1 4e! o&$e! 'e"%cl /!o.le' %cl"e $y/e!&e%o3 "%.e&e 'ell%&-&y/e 23 $y/e!c$ole&e!ole'%3 /e!%/$e!l cl! "%ee3 co!o!y !&e!y "%ee " 'yoc!"%l %,!c&%o1 Soc%l $%&o!y % o& %+%,%c&1 A."o'e % o,&3 o&e"e! " o-"%&e"e"1 A."o'%l -!y " CT c !e !e'!k.le1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely "%+o%;
A.
Chronic pancr!atiti B. Ath!rocl!roi of th! ,!!nt!ric art!ri! C. Crohn+ di!a! D. Irritabl! bo$!l yndro,! E. C!liac di!a! . 8y,pto,atic chol!lithiai . A,yloidoi H. Int!tinal ly,pho,a Explanation:
9",!ro" diord!r ,ay l!ad to ,alaborption r!"lting in $!ight lo and a chang! in th! charact!r of th! tool. Many of th!! ar! aociat!d $ith dyp!ptic y,pto,0 b"t only a f!$ pr!!nt $ith !1!r! abdo,inal pain. >or!ning potprandial pain that l!ad to a1oidanc! of food i charact!ritic of chronic occl"ion of 1ic!ral art!ri! #abdo,inal angina%. In thi 1ign!tt!0 th! pati!nt ha !1id!nc! of g!n!rali5!d ath!rocl!roi $hich f"rth!r rai! "picion for ath!rocl!roi of th! ,!!nt!ric art!ri! #Choic! B%. Ro"tin! i,aging t"di! ar! ""ally not infor,ati1!. Diagnoi r!;"ir! angiography or a Doppl!r "ltrao"nd. #Choic! A and C% 6ain acco,pani!d by ,alaborption ,ay b! d"! to chronic pancr!atiti or Crohn+ di!a!. Ho$!1!r0 th!! di!a! ""ally prod"c! abnor,al C and x-ray finding. #Choic! D% Irritabl! bo$!l yndro,! #IB8% do! not l!ad to $!ight lo. IB8 i a diagnoi of !xcl"ion. In thi ca!0 yo" ho"ld not ,a! thi diagnoi - !p!cially $ith th! abo1! pr!!ntation. #Choic! % Chol!lithiai pr!!nt $ith right "pp!r ;"adrant pain and fatty food intol!ranc!. It do! not ca"! chronic diarrh!a and $!ight lo. #Choic! E% C!liac di!a! i d"! to gl"t!n !niti1ity and it ""ally pr!!nt b!t$!!n 23-&3 y!ar of ag!. h!! pati!nt pr!!nt $ith f!at"r! of ,alaborption-li! chronic diarrh!a0 t!atorrh!a and flat"l!nc!. Abdo,inal angina i not a f!at"r! of thi !ntity. #Choic! and H% A,yloidoi and int!tinal ly,pho,a ar! "nli!ly in th! abo1! pati!nt. Ed"cational 4b/!cti1!: h! diagnoi of chronic ,!!nt!ric ich!,ia i "p!ct!d in pati!nt $ith "n!xplain!d chronic abdo,inal pain0 $!ight lo0 and food a1!rion. E1id!nc! of aociat!d ath!rocl!rotic di!a! i ""ally pr!!nt. 6hyical finding ar! ""ally nonp!cific. Abdo,inal !xa,ination ,ay r!1!al a br"it #G3= of pati!nt%. 80
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 70: A 2@-ye!-ol" ,e'le #%&$ ee!e C!o$F "%ee % .le &o e&1 I& % !eco''e"e" &$& $e .e /lce" o &o&l /!e&e!l &!%&%o1 A le,& .cl% e% l%e % /lce" #%&$o& y co'/l%c&%o1 T$e %,%o % &!&e" & !&e o, 0>cc$o! " %c!ee" &o 5cc$o! oe! &$e e& 20 $o!1 S$e co&%e o &o&l /!e&e!l &!%&%o ,o! &#o #eek " !e&! #%&$ co'/l%& o, /% " #ell%+ % $e! le,& !'1 O e'%&%o3 &$e le,& !' % #olle " /le1 T$e !"%l " l! /le !e /!ee&1 W$& $ol" .e &$e %%&%l &e/ % $e! '+e'e&; A. B. C. D. E.
Apply h!at to th! l!ft ar, 8tart h!parin !t ch!t x-ray R!,o1! cath!t!r 8tart antibiotic
Explanation:
hro,boi of th! "bcla1ian lin! or "p!rior 1!na ca1a can occ"r aft!r total par!nt!ral n"trition lin!. hro,boi i inidio" and ""ally pr!!nt aft!r a co"pl! of $!!. otal par!nt!ral n"trition lin! ho"ld g!n!rally b! plac!d in th! right atri",. h! irritating and hyp!ro,olar fl"id can tra",ati5! th! 1!in and l!ad to thro,boi. h! pati!nt $ill ""ally pr!!nt $ith a $oll!n ar, #$hich i pal!% and p"l! pr!!nt. h! $!lling ,ay !xt!nd fro, th! hand to th! n!c0 and !ngorg!d 1!in in th! "pp!r n!c and fac! ,ay b! 1iibl!. B!ca"! th! proc! i grad"al0 ,ot pati!nt $ill ha1! ,ini,al y,pto,. h! ,ot i,portant thing abo"t h!r ,anag!,!nt i to r!,o1! th! cath!t!r. h! long!r th! cath!t!r tay in0 th! high!r th! chanc! of irr!1!ribl! in/"ry #Choic! D%. #Choic! A% Application of h!at and !l!1ation of th! ar, ar! i,portant0 b"t can b! don! aft!r th! cath!t!r i r!,o1!d. 4nc! th! lin! i r!,o1!d0 th! $!lling ,ay ta! a f!$ $!! to r!ol1!. h! obtr"ction in th! "bcla1ian lin! can b! follo$!d by d"pl!x 1!no" "ltrao"nd. #Choic! B% 4nc! th! cath!t!r i r!,o1!d0 th! $!lling $ill d!cr!a!. Fltrao"nd ho"ld b! ord!r!d to doc",!nt th! thro,b". 6r!!nc! of thro,b" r!;"ir! anticoag"lation for a hort d"ration. r!at car! ,"t b! ta!n in not tarting intra1!no" lin! in th! aff!ct!d ar, in th! f"t"r!. Long-t!r, anticoag"lation i not n!c!ary0 b"t ho"ld b! contin"!d if th! y,pto, do not r!ol1!. #Choic! C% A ch!t x-ray i not diagnotic of "bcla1ian 1!in thro,boi. h! diagnoi i ,ad! by d"pl!x "ltrao"nd. #Choic! E% Blood c"lt"r! ar! not n!c!ary0 a thi i not an inf!ction b"t a 1!no" obtr"ction. If0 ho$!1!r0 th! lin! tip co,! bac a inf!ct!d0 antibiotic ,ayb! r!;"ir!d if y,pto, of f!1!r p!rit. Ed"cational 4b/!cti1!: 6rolong!d plac!,!nt of c!ntral lin! can l!ad to "bcla1ian 1!in thro,boi and r!"lt in ar, $!lling. Cath!t!r ho"ld b! r!,o1!d and d"pl!x ord!r!d to doc",!nt th! thro,b" and for th! n!!d of anticoag"lation.
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81
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 71: A 65-ye!-ol"#o' /!ee& #%&$ co'/l%& o, /% " #ell%+ oe! &$e %e! /ec& o, $e! !%+$& eye ,o! &$e /& &#o "y1 E'%&%o o, &$e eye !eel &e"e!e3 e"e'3 " !e"e oe! &$e 'e"%l c&$1 Sl%+$& /!e!e oe! &$e !e ce e/!e%o o, /!le& '&e!%l1 7%l c%&y % o!'l1 W$& % &$e 'o& l%kely "%+o%;
A.
Epicl!riti B. Dacryocytiti C. Hord!ol", D. Chala5ion E. 4rbital c!ll"liti Explanation:
Dacryocytiti i an inf!ction of th! lacri,al ac. It ""ally occ"r in infant and ad"lt o1!r th! ag! of &3. Ac"t! dacryocytiti i charact!ri5!d by th! "dd!n on!t of pain and r!dn! in th! ,!dial canthal r!gion. 8o,!ti,!0 a p"r"l!nt dicharg! i not!d fro, th! p"nct",. A f!$ pati!nt pr!!nt $ith f!1!r0 protration0 and an !l!1at!d l!"ocyt! co"nt. 8taphylococc" a"r!" and b!ta-h!,olytic 8tr!ptococc" ar! th! ""al inf!cting organi,. It ""ally r!pond to yt!,ic antibiotic th!rapy. #Choic! A% Epicl!riti i an inf!ction of th! !picl!ral ti"! b!t$!!n th! con/"ncti1a and cl!ra. 6ati!nt co,plain of an ac"t! on!t of ,ild to ,od!rat! dico,fort0 photophobia0 and $at!ry dicharg!. Exa,ination r!1!al diff"! or locali5!d b"lbar con/"ncti1al in/!ction. #Choic! C% Hord!ol", r!f!r to an abc! locat!d o1!r th! "pp!r or lo$!r !y!lid. Iti ""ally ca"!d by 8taphylococc" a"r!". It app!ar a a locali5!d r!d0 t!nd!r $!lling o1!r th! !y!lid. #Choic! D% Chala5ion pr!!nt a lid dico,fort. It i a chronic0 gran"lo,ato" infla,,ation of th! ,!ibo,ian gland. It app!ar a a hard0 painl! lid nod"l!. #Choic! E% 4rbital c!ll"liti r!f!r to an inf!ction pot!rior to th! orbital !pt",. It i "nilat!ral and ,or! co,,on in childr!n. It i ,anif!t!d by an abr"pt on!t of f!1!r0 proptoi0 r!triction of !xtraoc"lar ,o1!,!nt and $oll!n0 r!d !y!lid. Ed"cational 4b/!cti1!: Dacryocytiti pr!!nt $ith infla,,atory chang! in th! ,!dial canthal r!gion of th! !y!. 8taphylococc" a"r!" and b!ta-h!,olytic 8tr!ptococc" ar! th! ""al inf!cting organi,.
82
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 72: A 59-ye!-ol" #$%&e 'le /!ee& #%&$ /!o+!e%ely #o!e%+ "y/e oe! /e!%o" o, 0 'o&$1 4e lo co'/l% o, lo o, //e&%&e " #e%+$&1 4e $ $%&o!y o, c$!o%c "o"el lce! " co'/l% o, o'e e/%+&!%c "%co',o!&1 4e &ke !%&%"%e o " o,&1 4e "e%e lco$ol %&ke " 'ok%+1 4e % /l'.e! " $ .ee "o%+ &$% :o. ,o! 'o!e &$ 9> ye!1 4e "e%e y e/o!e &o /e&1 4% /le % @6'%3 Bloo" P!e!e % 895@ ''4+3 Te'/e!&!e % 961?C3 " Re/%!&o!y !&e % 85'%1 C$e& e'%&%o $o# .%l&e!l c!ckle1 C$e& -!y $o# 'l&%/le /le!l /lGe .%l&e!lly &$e!e % lo ' o &$e /e!%/$e!y o, &$e !%+$& l+1 CT +%"e" .%o/y o, &$e ' # "oe1 W$%c$ o, &$e ,ollo#%+ 'l%+cy % 'o& l%kely ee o .%o/y; A. B. C. D. E. .
M!tatatic to,ach canc!r M!tatatic colon canc!r M!tatatic pancr!atic canc!r Bronchog!nic carcino,a 6!riton!al ,!oth!lio,a 6l!"ral ,!oth!lio,a
Explanation:
6l!"ral in1ol1!,!nt i a hall,ar of ab!to !xpo"r! pl!"ral pla;"! ar! !!n in "p to G3= of pati!nt. Hi occ"pation i alo p"t hi, at high ri for ab!toi. Both ,!oth!lio,a and bronchog!nic carcino,a ar! aociat!d $ith th! ab!to !xpo"r! b"t bronchog!nic carcino,a i far ,or! co,,on and occ"r ,or! fr!;"!ntly aft!r ab!to !xpo"r!. Cigar!tt! ,oing act yn!rgitically $ith ab!to !xpo"r! in incr!aing th! ri for bronchog!nic carcino,a. Both pl!"ral ,!oth!lio,a and p!riton!al ,!oth!lio,a can occ"r aft!r ab!to !xpo"r!. Colon0 pancr!atic0 and to,ach canc!r ar! not fo"nd to b! aociat!d $ith ab!to !xpo"r! or ab!toi. Hi chronic d"od!nal "lc!r ,ight b! th! ca"! of hi !pigatric dico,fort. D"od!nal "lc!r n!1!r ca"! ,alignancy. Ed"cational 4b/!cti1!: R!,!,b!r bronchog!nic carcino,a i th! ,ot co,,on l"ng canc!r aociat!d $ith ab!to !xpo"r! $hil! ,alignant ,!oth!lio,a i al,ot !xcl"i1!ly aociat!d $ith ab!to !xpo"r! b"t i not th! ,ot co,,on ,alignancy aft!r ab!to !xpo"r!.
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83
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 73: A 99-ye!-ol" ,e'le /!ee& &o &$e o,,%ce ,o! &$e el&%o o, oe-#eek $%&o!y o, l%+$&%+-l%ke /% o &$e le,& %"e o, $e! ,ce1 T$e /% % e!y $!/ " ,eel l%ke .!1 A e/%o"e l& ,o! 8> eco"3 occ! 8>-2> &%'e "y3 " kee/ $e! ,!o' lee/%+3 e&%+3 o! #o!k%+1 S$e "e%e y $%&o!y o, &!'3 'e"%c&%o e o! !ece& !+e!y1 7%&l %+ !e #%&$% o!'l l%'%&1 W$& % &$e 'o& l%kely "%+o%; A. B. C. D. E.
Maxillary in"iti Carotidynia rig!,inal n!"ralgia H!rp! 5ot!r B"rning ,o"th yndro,!
Explanation:
rig!,inal n!"ralgia i charact!ri5!d by pain in th! ditrib"tion of th! branch! of th! fifth n!r1!. h! diagnoi i g!n!rally clinical and ba!d on th! charact!ritic pain0 $hich i !1!r!0 int!n!0 b"rning or !l!ctric hoc-li!. hi y,pto, occ"r in paroxy, that lat a f!$ !cond to ,in"t! !ach0 b"t occ"r ,any ti,! a day. h! trigg!r factor ,ay 1ary0 and th! ca"! r!,ain "nno$n. Carba,a5!pin! i th! dr"g of choic!. #Choic! A% Maxillary in"iti can alo prod"c! facial pain ho$!1!r0 th! pain int!nity i ,"ch l! than trig!,inal n!"ralgia0 contant0 and locali5!d to th! ,axillary in". "rth!r,or!0 pati!nt ""ally ha1! an aociat!d f!1!r and naal !cr!tion. 8in" x-ray ,ay ho$ opacification of th! ,axillary in"0 and tr!at,!nt in1ol1! antibiotic andor drainag!. #Choic! B% Carotidynia i a n!"rological condition ca"!d by infla,,ation of th! carotid and th! 1ag". h! pain i harp and locali5!d to th! carotid art!ry ditrib"tion in th! n!c. F"ally0 th! int!nity of pain i ,"ch l!. h! diagnoi i clinical0 altho"gh an MRI i o,!ti,! r!;"ir!d. #Choic! D% H!rp! 5ot!r can alo prod"c! !xcr"ciating pain: ho$!1!r0 th! 1ir" ""ally occ"r along a d!r,ato,al ditrib"tion and pr!!nt $ith 1!icl! or a ,ac"lar rah. #Choic! E% B"rning ,o"th yndro,! i a rar! ca"! of facial pain. Iti ca"!d by a 1ir" and th! indi1id"al ha r!dd!n!d ,"coa and ha ignificant pain. h! condition i aggra1at!d by dryn!. It i tr!at!d by "pporti1! car!. Ed"cational 4b/!cti1!: 6aroxy,al0 lightning-li! pain on th! fac! i ""ally d"! to trig!,inal n!"ralgia. Carba,a5!pin! i th! dr"g of choic!.
84
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 74: A 59-ye!-ol" ' co'e &o &$e o,,%ce ,o! $% !o&%e ,ollo#-/ %%&1 4e % ko# $y/e!&e%e ,o! &$e /& 85 ye!3 " % o l%%o/!%l " $y"!oc$lo!o&$%%"e1 4% .loo" /!e!e % 85>?> '' 4+3 /le % @2'%3 !e/%!&%o !e 80'%3 " &e'/e!&!e % ?@10 (961@@ C)1 7%l c%&y % o!'l1 "co/y !eel !!o#3 &o!&o !e&%l !&e!%ole3 co//e! #%!%+3 " A7 %ck%+1 T$e !e& o, &$e e'%&%o % o!'l1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely "%+o%; A. B. C. D. E.
9or,al r!tina rad! I Hyp!rt!ni1! R!tinopathy rad! II Hyp!rt!ni1! R!tinopathy rad! III Hyp!rt!ni1! R!tinopathy rad! I7 Hyp!rt!ni1! R!tinopathy
Explanation:
8yt!,ic hyp!rt!nion aff!ct th! r!tinal circ"lation a $!ll a th! choroidal circ"lation. h! !;"!nc! of !1!nt b!gin $ith focal pa, of art!riol!0 follo$!d by progr!i1! cl!roi and narro$ing. If hyp!rt!nion i l!ft "ncontroll!d0 thi !1!nt"ally l!ad to fla,!hap!d h!,orrhag! fro, r"pt"r!d 1!!l0 for,!d !x"dat! and papill!d!,a. K!ith->ag!n!r claification: rad! I 8light A7 nicing rad! II Copp!r $iring0 A7 d!pr!ion $ith h",ping !nd rad! III 8il1!r $iring0 fla,! hap!d h!,orrhag!0 !x"dat! rad! I7 la,! hap!d h!,orrhag!0 !x"dat! and papill!d!,a Ed"cational 4b/!cti1!: Kno$ th! 1ario" tag! of hyp!rt!ni1! r!tinopathy.
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85
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 75: A 2?-ye!-ol" 'le #%&$ 6-ye! $%&o!y o, 4I7 %,ec&%o /!ee& #%&$ c$!o%c3 ee!e "%!!$e oc%&e" #%&$ 'l%e3 e3 o!e% " ."o'%l c!'/1 4% l& CD0 co& # @> cell''1 A 'o"%,%e" c%"-,& &% o, &ool /ec%'e $o# 06'' oocy&1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely '%c!oo!+%' !e/o%.le ,o! &$% co"%&%o;
A.
Mycobact!ri", a1i", co,pl!x B. Cryptoporidi", par1", C. Iopora b!lli D. 6n!",ocyti carinii E. Microporidia Explanation:
A ,odifi!d acid-fat tain ho$ing oocyt in th! tool i 1!ry "gg!ti1! of an inf!ction $ith Cryptoporidi", par1",. hi organi, can ca"! !1!r! diarrh!al di!a! in both i,,"noco,p!t!nt and i,,"noco,pro,i!d indi1id"al. HI7-inf!ct!d pati!nt $ith a ,or! pr!!r1!d CD& co"nt t!nd to ha1! a !lf-li,iting illn!0 $h!r!a AID8 pati!nt $ith CD& co"nt W0 (3 c!ll,,< t!nd to ha1! a ,or! p!rit!nt clinical co"r!. #Choic! C% Altho"gh th! diagnoi of Iopora b!lli i alo "gg!t!d by th! pr!!nc! of acid-fat oocyt0 inf!ction $ith Iopora b!lli ar! not a co,,on a Cryptoporidi", in th! Fnit!d 8tat!. #Choic! A% Mycobact!ri", a1i", co,pl!x i aociat!d $ith l"ng inf!ction in i,,"noco,p!t!nt pati!nt $ith chronic l"ng di!a! ho$!1!r0 it ca"! di!,inat!d di!a! $ith bo$!l infiltration and ,alaborption in pati!nt $ith !1!r! i,,"n! co,pro,i!. "rth!r,or!0 it i not charact!ri5!d by oocyt in th! tool. #Choic! D% 6n!",ocyti carinii i aociat!d $ith p"l,onary di!a!0 not diarrh!a. #Choic! E% h! Microporidia organi,0 along $ith Ent!rocyto5oon bi!n!"i and Enc!phalito5oon int!tinali0 ar! rar! ca"! of diarrh!a in i,,"noco,p!t!nt hot ho$!1!r0 th!! ar! aociat!d $ith !1!r! ,alaborption and p!rit!nt diarrh!a in HI7-inf!ct!d pati!nt. "rth!r,or!0 ,icroporidioi i charact!ri5!d by th! pr!!nc! of por! and not oocyt in th! tool. Ed"cational 4b/!cti1!: Cryptoporidi", par1", i a ,a/or ca"! of chronic diarrh!a in HI7inf!ct!d pati!nt $ith CD& co"nt l! than0 (3 c!ll,,<.
86
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 76: A 26-ye!-ol" ' /!ee& &o &$e /$y%c%F o,,%ce #%&$ &#o"y $%&o!y o, 'l&%/le y'/&o'3 %cl"%+ !$ o $% &!k3 $e"c$e3 ,&%+e3 'l%e3 'yl+%3 " $%+$-+!"e ,ee!1 T$e !$ % o& oc%&e" #%&$ /%3 %&c$%+3 o! .!%+1 I& $ e/"e" oe! &$e l& &#o "y1 4e #e& o c'/%+ &!%/ % 7e!'o& &#o #eek +o3 " !ecll &%ck .%&e & &$& &%'e1 T$e!e % %+le le%o o $% &!k3 #$%c$ % e!y&$e'&o #%&$ ce&!l cle!%+1 T$e !e& o, &$e e'%&%o % !e'!k.le1 W$& % &$e 'o& //!o/!%&e e& &e/ % &$e '+e'e& o, &$% /&%e&; A. B. C. D. E.
6!rfor, ELI8A for confir,ation of Ly,! di!a! 6!rfor, $!t!rn blot for confir,ation of Ly,! di!a! i1! hi, oral doxycyclin! i1! hi, oral a,oxicillin i1! hi, intra1!no" c!ftriaxon!
Explanation:
hi pati!nt ha ,any claic f!at"r! of !arly-locali5!d Ly,! di!a!0 $hich incl"d! !ryth!,a ,igran #EM% and nonp!cific co,plaint "ch a ,alai!0 h!adach!0 ,"cl! pain /oint pain0 and ly,phad!nopathy. In aff!ct!d pati!nt. EM ""ally occ"r $ithin on! ,onth of th! tic bit!. h! EM rah app!ar on th! ar, and ,oit ar!a of th! body0 "ch a th! axilla!0 groin0 andor tr"n. h! EM rah i !ryth!,ato" and ,ay pr!ad $ith a 5on! of c!ntral cl!aring #gi1ing th! claic Ub"ll+ !y!V app!aranc!% or ,ay b! "nifor,ly r!d. It ""ally do! not prod"c! y,pto, "ch a pain0 itching0 or b"rning. EM i pathogno,onic for Ly,! di!a!: th!r!for!0 $h!n a pati!nt ha typical EM0 th! n!xt t!p i phar,acological tr!at,!nt $ith oral doxycyclin!. #Choic! A and B% h! diagnoi of !arly-locali5!d Ly,! di!a! i p"r!ly clinical th!r!for!0 th!r! i no n!!d to p!rfor, !rologic t!t in a pati!nt $ith claic EM0 !p!cially if th!r! i a cl!ar hitory of tic bit!. 8!rologic t!ting i r!co,,!nd!d for pati!nt $ith an int!r,!diat! pr!t!t probability of Ly,! di!a! and ho"ld incl"d! ELI8A0 follo$!d by $!t!rn blot if r!"lt ar! poiti1! or !;"i1ocal. 8!rologic t!t ar! ""ally n!gati1! in !arly-locali5!d Ly,! di!a!. #Choic! D% 4ral doxycyclin! i g!n!rally pr!f!rr!d o1!r a,oxicillin b!ca"! it i alo !ff!cti1! againt poibl! co!xit!nt !hrlichioi0 $hich i pr!ad by th! a,! 1!ctor Ly,! di!a!. In pr!gnant $o,!n0 ho$!1!r0 a,oxicillin i th! tr!at,!nt of choic!. #Choic! E% Intra1!no" th!rapy $ith c!ftriaxon! i g!n!rally indicat!d for !arly-di!,inat!d and lat! Ly,! di!a!. Ed"cational 4b/!cti1!: Eryth!,a chronic", ,igran in a pati!nt $ith a tic bit! hitory $arrant i,,!diat! tr!at,!nt $ith doxycyclin!. 8!rologic t!ting i not n!c!ary to confir, a Ly,! di!a! diagnoi if th! pati!nt pr!!nt $ith claic M.
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87
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 77: A &*-y!ar-old ,al! i bro"ght to th! !,!rg!ncy d!part,!nt i,,!diat!ly aft!r ha1ing a prolong!d !i5"r! !piod!. Hi fa,ily d!crib! a pat ,!dical hitory of grand ,al !i5"r!. H! ha b!!n on ph!nytoin for th! pat 23 y!ar0 b"t topp!d taing th! dr"g ix ,onth ago b!ca"! h! had not had any !i5"r! in th! lat nin! y!ar. H! i oth!r$i! h!althy and had b!!n doing $!ll "ntil thi !i5"r! !piod!. H! do! not "! tobacco0 alcohol or dr"g. H! i af!bril!. Hi blood pr!"r! i 2<'(( ,, Hg0 r!piration ar! 2(,in and p"l! i ',in. H! app!ar conf"!d and l!thargic. Ch!t a"c"ltation i "nr!,arabl!0 and hi abdo,!n i oft and nont!nd!r. A li,it!d n!"rologic !xa,ination i non-focal. Hi laboratory r!port ho$: 8!r", odi", 2&3 ,E;L 8!r", potai", &3 ,E;L Chlorid! 23< ,E;L Bicarbonat! 2) ,E;L Blood "r!a nitrog!n #BF9% *3 ,gdL 8!r", cr!atinin! 3.( ,gdL Blood gl"co! ( ,gdL Ch!t x-ray and "rinalyi ar! $ithin nor,al li,it0 and a C can of th! h!ad i "nr!,arabl!. >hich of th! follo$ing i th! ,ot appropriat! n!xt t!p in th! ,anag!,!nt of thi pati!nt+ ,!tabolic acidoi A. B. C. D. E.
i1! intra1!no" bicarbonat! Ch!c !r", !ton! Ch!c !r", lipa! 4b!r1! and r!p!at th! lab aft!r * ho"r 8tart dopa,in!
Explanation:
hi pati!nt ha an anion gap ,!tabolic acidoi follo$ing a grand ,al #tonic-clonic% !i5"r!. A pot-!i5"r! anion gap ,!tabolic acidoi i claically th! r!"lt of lactic acidoi. 8!i5"r! r!"lt in th! acc!l!rat!d prod"ction of lactic acid in th! ,"cl! and r!d"c!d h!patic lactat! "pta!. hi pot-ictal lactic acidoi i trani!nt and typically r!ol1! $ithin '3 to 3 ,in"t!. In thi pati!nt0 th! ,ot appropriat! tr!at,!nt i ob!r1ation and r!p!ating th! ch!,itry pan!l aft!r * ho"r to !! if th! acidoi ha r!ol1!d on it o$n. If it ha not r!ol1!d. It i b!t to loo for oth!r pot!ntial ca"! of ,!tabolic acidoi. #Choic! A% h! "! of bicarbonat! in th! tr!at,!nt of lactic acidoi or !toacidoi i 1!ry contro1!rial. It i r!co,,!nd!d only in !1!r! ac"t! acidoi #pH W ).*%. "ll corr!ction $ith bicarbonat! ho"ld not b! o"ght only a "ffici!nt a,o"nt of bicarbonat! ho"ld b! gi1!n to corr!ct th! pH to ).*. In lactic acidoi0 bicarbonat! tr!at,!nt ,ay paradoxically d!pr! cardiac p!rfor,anc! and $or!n th! acidoi by !nhancing lactat! prod"ction. #Choic! B% h! co,,on ca"! of !toi incl"d! diab!t!0 alcoholi, and tar1ation. h! pati!nt+ hitory do! not indicat! a ri for !toi. #Choic! C% 8!r", lipa! l!1!l ar! g!n!rally "!d to a! for pancr!atic di!a!0 b"t th!y ,ay alo b! !l!1at!d in diab!tic !toacidoi and oth!r condition ,aing th! t!t poorly p!cific for any on! di!a! proc!. #Choic! E% h! pati!nt+ blood pr!"r! i $ithin nor,al li,it. Dopa,in! i a poiti1! inotrop! and a 1aocontrictor "!d in pati!nt 88
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* $ith hypot!nion $ho do not r!pond to l! aggr!i1! ,!a"r! "ch a intra1!no" fl"id. Hypot!nion $ith poor !nd organ p!rf"ion ,ay ca"! lactic acidoi0 and dopa,in! ,ay b! "!d in "ch a c!nario. Ed"cational 4b/!cti1!: 6otictal lactic acidoi co,,only occ"r follo$ing a tonic-clonic !i5"r!. It i a trani!nt anion gap ,!tabolic acidoi that r!ol1! $itho"t tr!at,!nt $ithin '3 to 3 ,in"t! follo$ing r!ol"tion of !i5"r! acti1ity.
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89
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 78: A 0@-ye!-ol" #o' co'e &o &$e o,,%ce .ece $e! !e+l! c!ee%+ '''o+!' !eele" %!!e+l! "e%&%e1 R"%o+!/$%c-+%"e" ee"le .%o/y $o# e%"ece o, %%e lo.l! c!c%o'1 T$e &'o! % $o!'oe !ece/&o! /o%&%e (4R )1 !&$e! %e&%+&%o !eel %ole'e& o, &$e %ll!y ly'/$ o"e &$e o&$e! .!e& ee' &o .e /!e"1 No "%&& 'e&&% % "e&ec&e"1 S$e "e!+oe 'o"%,%e" !"%cl '&ec&o'y3 lo+ #%&$ !"%o&$e!/y1 S$e % &$e /!ec!%.e" ":& c$e'o&$e!/y " &'o%,e ,o!5ye!1 T$% /&%e&F e o, &'o%,e %c!ee $e! !%k ,o! "eelo/%+ #$%c$ o, &$e ,ollo#%+ cce! A. B. C. D. E.
41arian canc!r Endo,!trial canc!r L"ng canc!r 6ancr!atic canc!r C!r1ical canc!r
Explanation:
C"rr!nt r!!arch t"di! ha1! ho$n that th! "! of th! anti-!trog!n0 ta,oxif!n0 a an ad/"1ant for !arly tag! br!at canc!r r!d"c! th! ri of r!c"rr!nc! of th! original canc!r0 a $!ll a th! ri of d!1!loping n!$ canc!r in th! oth!r br!at. 9!1!rth!l! th!r! i o,! ri aociat!d $ith ta,oxif!n "!. a,oxif!n incr!a! th! ri of t$o typ! of pot!ntially lif!-thr!at!ning "t!rin! canc!r #0% !ndo,!trial canc!r0 $hich ari! in th! lining of th! "t!r"0 and #*% "t!rin! arco,a0 $hich ari! in th! ,"c"lar $all of th! "t!r". h! Br!at Canc!r 6r!1!ntion rial #BC6% ho$!d that $o,!n $ho too ta,oxif!n had ,or! than t$ic! th! chanc! of d!1!loping !ndo,!trial canc!r0 co,par!d to $o,!n $ho too plac!bo. Int!r!tingly0 ,ot of th! !ndo,!trial canc!r ha1! b!!n fo"nd in th! !arly tag!0 and tr!at,!nt ha ""ally b!!n !ff!cti1!: ho$!1!r0 th! di!a! ,ay b! lif!-thr!at!ning in o,! pati!nt. "rth!r,or!0 $o,!n $ho ar! taing ta,oxif!n b"t ha1! had a hyt!r!cto,y ar! not at incr!a!d ri for th!! canc!r. Ed"cational 4b/!cti1!: a,oxif!n ha a ,ix!d agonit and antagonit acti1ity on !trog!n r!c!ptor. Etrog!nic !ff!ct of ta,oxif!n incr!a! th! ri of !ndo,!trial canc!r and 1!no" thro,boi.
90
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 79: A 'G-y!ar-old ,an pr!!nt $ith a 0-y!ar hitory of i,pot!nc! and d!cr!a!d libido. H! ha a 0G-y!ar hitory of typ! * diab!t! ,!llit"0 $hich i controll!d $ith di!t. H! d!ni! any cardiac probl!,0 1i"al chang! or y,pto, of n!"ropathy. h! g!nito"rinary !xa,ination r!1!al d!cr!a!d t!tic"lar i5! and ab!nt gyn!co,atia. h! r!t of th! phyical !xa,ination i "nr!,arabl!. h! laboratory r!port ho$: H!,oglobin A2c G= !tot!ron! *.3 ngdL #9or,al <-03 ngdL% LH hat i th! b!t n!xt t!p in th! ,anag!,!nt of thi pati!nt A. B. C. D. E.
In"lin th!rapy Angiography of th! d!!p art!ri! of th! p!ni Doppl!r "ltraonography of p!nil! blood flo$ M!a"r! th! !r", prolactin l!1!l M!a"r! th! !r", !tradiol l!1!l
Explanation:
Er!ctil! i,pot!nc! in diab!tic pati!nt ,ay b! d"! to ,"ltipl! r!aon0 incl"ding a"tono,ic n!"ropathy0 ,!dication0 f"nctional hypogonadi,0 and probl!, $ith p!nil! circ"lation. It i th" !!ntial to ha1! a broad diff!r!ntial diagnoi to appropriat!ly incl"d! all pla"ibl! ca"! of th! pati!nt+ y,pto,. "nctional hypogonadi, i charact!ri5!d by lo$ t!tot!ron! and lo$ gonadotrophin #LH and 8H% l!1!l in th! pr!!nc! of a ignificant yt!,ic illn! #!.g.0 "ncontroll!d diab!t!% th! "nd!rlying pathology i d!f!cti1! gonadotrophin-r!l!aing hor,on! #nRH% !cr!tion. In contrat0 pri,ary #t!tic"lar% hypogonadi, i charact!ri5!d by !l!1at!d !r", gonadotrophin l!1!l. In thi ca! th! pati!nt+ diab!t! i $!ll-controll!d0 a !1id!nc!d by hi nor,al Hb A2c l!1!l. At thi point0 th! ,ot li!ly diagnoi i !condary #c!ntral% hypogonadi,0 $hich i charact!ri5!d by hypogonadi,0 lo$ t!tot!ron! l!1!l and inappropriat!ly nor,al gonadotrophin l!1!l. M!a"r!,!nt of !r", prolactin l!1!l i th! ,ot i,portant bioch!,ical t!t to p!rfor, in pati!nt $ith "p!ct!d c!ntral hypogonadi,. R!gardl! of th! ca"!0 high !r", prolactin l!1!l inhibit th! r!l!a! of nRH0 th!r!by r!"lting in hypogonadi,. 6rolactin-!cr!ting pit"itary t",or i on! of th! ,ot i,portant ca"! of !l!1at!d prolactin l!1!l. #Choic! E% In pri,ary hypogonadi,0 "pranor,al !r", 8H and LH conc!ntration ti,"lat! t!tic"lar aro,ata! acti1ity0 th!r!by l!ading to incr!a!d !tradiol prod"ction. #Choic! A% h! pati!nt+ nor,al Hb A2c l!1!l indicat! that hi diab!t! i $!ll controll!d $ith hi c"rr!nt r!gi,!n th!r!for!0 in"lin tr!at,!nt i not $arrant!d. #Choic! C and B% D"pl!x Doppl!r "ltraonography or angiography of th! p!nil! d!!p art!ri! ,ayb! indicat!d $h!n a 1ac"lar !tiology of !r!ctil! i,pot!nc! i b!ing "p!ct!d. 8inc! th! pati!nt+ f!at"r! ar! ,or! "gg!ti1! of c!ntral hypogonadi,0 th!! t!t ho"ld not b! "tili5!d at thi ti,!. Ed"cational 4b/!cti1!: C!ntral or !condary hypogonadi, in ,al! i charact!ri5!d by lo$ l!1!l of t!tot!ron! $ith lo$ or inappropriat!ly nor,al !r", gonadotropin l!1!l.
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91
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 80: A 0>-ye!-ol" Cc% ' co'e &o &$e e'e!+ecy "e/!&'e& .ece o, ,ee!3 "!y co+$3 " $o!&e o, .!e&$1 Sy'/&o' &!&e" 20 $o! +o1 4e "e%e $e'o/&y%1 4e # !ece&ly "%c$!+e" ,!o' &$e $o/%&l ,&e! eco" cycle o, c$e'o&$e!/y ,o! c&e 'yelo%" leke'%1 4e "oe o& e &o.cco3 lco$ol3 o! "!+1 4% &e'/e!&!e % 9@1? C (8>21> )3 .loo" /!e!e % 82>> ''4+3 /le % 882'% " !e/%!&%o !e 2@'%1 T$e /&%e& /le o%'e&!y $o#e" @6 & !oo' %!1 E'%&%o $o# "%,,e c!ckle ll oe! &$e l+ ,%el"1 4% c$e& -!y $o# "%,,e %&e!&%&%l %,%l&!&e1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely ce o, $% co"%&%o;
A.
Coccidioido,ycoi B. Hitopla,oi C. "b!rc"loi D. HI7 inf!ction E. 6n!",ocyti carinii . Hodgin+ ly,pho,a . B!ryllioi H. 8ilicoi I. M!tatatic t!tic"lar canc!r . Bronchog!nic carcino,a K. 8arcoidoi L. Rh!",atoid nod"l! M. >!g!n!r+ gran"lo,atoi 9. Ap!rgilloi 4. Candida pn!",onia Explanation:
h! pati!nt in thi 1ign!tt! i i,,"noco,pro,i!d d"! to hi ch!,oth!rapy0 $hich p"t hi, at high ri for n",!ro" opport"nitic inf!ction. h! clinical pr!!ntation "gg!t atypical pn!",onia0 $hich along $ith charact!ritic ch!t x ray finding i "gg!ti1! of pn!",ocyti carinii #6. Carinii% pn!",onia. 6n!",ocyti carinii i an opport"nitic pathog!n0 and an i,portant ca"! of pn!",onia in i,,"noco,pro,i!d hot. It nat"ral habitat i th! l"ng0 and th! inc"bation p!riod rang! fro, &-( $!!. It i airborn! tran,itt!d. 6. Carinii pn!",onia i charact!ri5!d by dypn!a0 f!1!r0 and a nonprod"cti1! co"gh. 6hyical !xa,ination $o"ld ho$ tachypn!a0 tachycardia0 and cyanoi $ith ,ini,al ch!t finding. Bilat!ral diff"! int!rtitial infiltrat! b!ginning in th! p!rihilar r!gion i a charact!ritic finding on ch!t x-ray in 6. Carinii pn!",onia. 6. Carinii ,ay di!,inat! o"tid! th! l"ng0 and th! ,ot co,,on it! of !xtrap"l,onary in1ol1!,!nt ar! th! ly,ph nod!0 pl!!n0 li1!r0 and bon! ,arro$. #Choic! 9% Ap!rgilloi can alo b! !!n in i,,"noco,pro,i!d pati!nt ho$!1!r0 th! ch!t x-ray typically ho$ a olid ,a "rro"nd!d by a radiol"c!nt cr!c!nt #cr!c!nt ign0 Monod+ ign%. #Choic! 3% Candida i an !xtr!,!ly rar! organi, to ca"! pn!",onia in any pati!nt. It i oft!n coloni5!d in bronchial !pith!li", and o,!ti,! th! p"t", and c"lt"r! ,ay b! poiti1! ho$!1!r0 it i not th! ca"! of pn!",onia. Al$ay loo for o,!thing !l!. hin abo"t 92
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* candida if th! ;"!tion i taling abo"t !ophagiti0 !ndocarditi0 !ndophthal,iti0 h!patopl!nic di!a!0 and ,!ningiti. Ed"cational 4b/!cti1!: 6. Carinii i an opport"nitic pathog!n0 and an i,portant ca"! of pn!",onia in i,,"noco,pro,i!d hot. Bilat!ral diff"! int!rtitial infiltrat! b!ginning in th! p!rihilar r!gion i a charact!ritic finding on ch!t x-ray.
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93
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 81: A 90-ye!-ol" #$%&e #o' co'e &o &$e E'e!+ecy Roo' co'/l%%+ o, "%,,%cl& .!e&$%+ &$& &!&e" ""ely ee!l $o! +o1 S$e $ ee! $" c$ y'/&o' .e,o!e1 4e! /& 'e"%cl $% &o# % %+%,%c& ,o! !$e'&o%" !&$!%&%1 4e! c!!e& 'e"%c&%o %cl"e /!oe " o!l co&!ce/&%e1 S$e 'oke 8 /ck "y3 .& "oe o& co'e lco$ol1 4e! .loo" /!e!e % 88>> ''4+ " $e!& !&e % 8>5'%1 L+ !e cle! o cl&&%o1 EK " c$e& -!y !e o!'l1 7e&%l&%o/e!,%o c # /e!,o!'e"3 .& &$e !el& #e!e %cocl%e1 W$& % &$e .e& e& &e/ % &$e '+e'e& o, &$% /&%e&; A. B. C. D. E.
6"l,onary angiography 6"l,onary f"nction t!t 7!no" "ltraonography Contrat phl!bography ran!ophag!al !chocardiography
Explanation: hi pati!nt i "nd!rgoing a diagnotic $or-"p for p"l,onary thro,bo!,boli,. h! ""al o"rc! of !,boli ca"ing thi condition i d!!p 1!no" thro,boi #D7I% of th! lo$!r !xtr!,iti!. 4ral contrac!pti1! "! i an i,portant ri factor for D760 !p!cially $h!n co,bin!d $ith ,oing. 6"l,onary thro,bo!,boli, i diffic"lt to diagno! and ""ally r!;"ir! th! co,bination of !1!ral diagnotic ,odaliti!. So" ho"ld b! fa,iliar $ith th! o1!rall ch!,! of diagnotic $or-"p in th!! pati!nt. h! firt t!t that i ""ally !,ploy!d i 1!ntilationp!rf"ion canning. If th! claic patt!rn of ,i,atch!d p!rf"ion d!f!ct i ob!r1!d0 yo" ho"ld proc!!d $ith tr!at,!nt. If th! can i nor,al0 yo" can act"ally r"l! o"t ignificant p"l,onary thro,bo!,boli,. B"t0 in a "btantial n",b!r of pati!nt0 th! 1!ntilationp!rf"ion canning r!"lt ar! inconcl"i1!. h! n!xt b!t t!p in thi ca! i 1!no" "ltraonography to r!1!al D7 or C angiogra, of th! ch!t. Diagnoing D7 ,a! th! probability of p"l,onary thro,bo!,boli, 1!ry high0 and yo" ho"ld proc!!d $ith tr!at,!nt. Altho"gh conid!r!d th! gold tandard0+ p"l,onary angiography #Choic! A%0 an in1ai1! proc!d"r! i !,ploy!d if 1!no" "ltraonography or C angiogra, i n!gati1!. Ch!t C angiogra, i alo fr!;"!ntly "!d in ind!t!r,inat! ca! of p"l,onary !,boli,0 b"t th! probl!, $ith C angiogra, i that it can diagno! only larg! !,boli. 8,all !,boli can b! !aily ,i!d. Contrat phl!bography #Choic! D% i an in1ai1! proc!d"r! that $a larg!ly r!plac!d by 1!no" "ltraonography. ran!ophag!al !chocardiography #Choic! E% i 1!ry "!f"l i diagnoing aortic di!ction0 b"t ha no rol! in diagnoing p"l,onary thro,bo!,boli,. 6"l,onary f"nction t!t #Choic! B% ar! "!f"l for diagnoing obtr"cti1! and r!tricti1! di!a!. h!y ha1! no rol! in thi pati!nt at thi ti,!.
Ed"cational 4b/!cti1!: If 1!ntilationp!rf"ion can i diagnotic $or-"p for p"l,onary "ltraonography to r!1!al D7 or in1ai1! proc!d"r! and ho"ld b! C angiogra, i n!gati1!.
94
inconcl"i1! in pati!nt "nd!rgoing thro,bo!,boli,0 ord!r 1!no" C angiogra,. 6"l,onary angiography i an !,ploy!d only if 1!no" "ltraonography or
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 82: A &*-y!ar-old Ca"caian f!,al! pr!!nt to clinic co,plaining of !1!r! fatig"! and dar y!llo$ "rin!. "rth!r in;"iry r!1!al that h! i alo !xp!ri!ncing anor!xia0 na"!a0 and ,alai!. 8h! i "nc!rtain a to $h!n h!r y,pto, b!gan and b!li!1! th!y ca,! on grad"ally. 8h! ha no chronic illn!!0 ta! no ,!dication0 and ha no no$n dr"g all!rgi!. 8h! ad,it to ha1ing "nprot!ct!d int!rco"r! $ith ix diff!r!nt partn!r $ithin th! pat y!ar. H!r i,,"ni5ation hi tory do! not incl"d! 1accination againt h!patiti B 1ir". Laboratory t!ting r!1!al th! follo$ing: Li1!r t"di! otal bilir"bin &.G ,gdL Alalin! phophata! 2&* FL Apartat! a,inotranf!ra! #A8I 84% 2(& FL Alanin! a,inotranf!ra! #AL0 86% <&G FL >hich of th! follo$ing i th! b!t ,!an of cr!!ning for h!patiti B inf!ction A. B. C. D. E.
HBAg and IgM anti-HBc HBAg and anti-HB HBcAg HB!Ag Anti-HB!
Explanation:
Exp!ct!d laboratory finding in a pati!nt $ith ac"t! h!patiti incl"d! ignificant !l!1ation in AL and A8 #$ith AL A8%0 follo$!d by ri! in bilir"bin and alalin! phophata!. B!ca"! thi pati!nt+ li1!r f"nction t!t ar! "gg!ti1! of ac"t! h!patiti and h! r!port hitory of ,"ltipl! !x partn!r0 h! i at high ri for inf!ction $ith h!patiti B 1ir" and ho"ld b! cr!!n!d accordingly. h! !rological ,ar!r of h!patiti B d!1!lop o1!r a p!cific ti,! co"r!0 a o"tlin!d b!lo$. HBAg: h! firt 1irological ,ar!r d!t!ct!d in th! !r", aft!r inoc"lation0 it pr!c!d! both th! !l!1ation of !r", a,inotranf!ra! and th! on!t of clinical y,pto,. It r!,ain d!t!ctabl! d"ring th! !ntir! y,pto,atic pha! of ac"t! h!patiti B and "gg!t inf!cti1ity. Anti-HB: App!aring in th! !r", aft!r !ith!r "cc!f"l HB7 1accination or th! cl!aranc! of HBAg0 thi ,ar!r r!,ain d!t!ctabl! for lif!. It !r1! a an indicator of non inf!cti1ity and i,,"nity. Ho$!1!r0 th!r! i a ti,! lag b!t$!!n th! diapp!aranc! of HBAg and th! app!aranc! of anti-HB in th! !r",0 $hich i t!r,!d th! U$indo$ p!riod HBcAg: hi ,ar!r i not d!t!ctabl! in !r", a it i nor,ally !;"!trat!d $ithin th! HBAg coat. Anti-HBc: App!aring in th! !r", hortly aft!r th! app!aranc! of HBAg0 thi ,ar!r r!,ain d!t!ctabl! long aft!r th! pati!nt r!co1!r. h! 0gM fraction ignal th! ac"t! pha! of di!a!0 $h!r!a th! lg fraction ignal r!co1!ry fro, th! di!a!. B!ca"! IgM anti-HBc i pr!!nt in th! U$indo$ p!riod0V iti an i,portant tool for diagnoi $h!n HBAg ha b!!n cl!ar!d and anti-HB i not y!t d!t!ctabl!. h" 0gM anti-HBc i th! ,ot p!cific ,ar!r for diagnoi of ac"t! h!patiti B. HB!Ag: hi antig!n i d!t!ctabl! hortly aft!r th! app!aranc! of HBAg and indicat! acti1! 1iral r!plication and inf!cti1ity. It i aociat!d $ith th! pr!!nc! of HB7 D9A. HB!Ag t!nd to diapp!ar horlly aft!r a,inotranf!ra! l!1!l p!a and b!for! HBAg i !li,inat!d0 and i follo$!d by th! app!aranc! of anti-HB!. 8ho"ld it
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95
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* p!rit for ,or! than thr!! ,onth0 th!r! i an incr!a!d li!lihood of chronic h!patiti B. Anti-HB!: hi ,ar!r "gg!t th! c!ation of acti1! 1iral r!plication and lo$ inf!cti1ity. h!r!for!0 t!ting for both HBAg and anti-HBc off!r th! b!t cr!!ning for ac"t! h!patiti B inf!ction0 a it $ont ,i th! $indo$ p!riod $h!n HBAg ha diapp!ar!d b"t anti-HB ha not y!t app!ar!d in th! !r",. #Choic! B% !ting for HBAg and anti-HB $ill not diagno! h!patiti B inf!ction in tho! pati!nt $ho ar! in th! $indo$ p!riod. #Choic! C% HBcAg i not d!t!ctabl! in !r", and i th!r!for! of no h!lp in !tablihing th! diagnoi. #Choic! D% HB!Ag i a good indicator of inf!cti1ity b"t i a poor cr!!ning tool a it l!1!l typically fall !arly in th! co"r! of th! di!a!. #Choic! E% Anti-HB! i a good indicator that 1iral r!plication ha c!a!d. Ho$!1!r0 it !niti1ity i too poor to diagno! an ac"t! inf!ction. Ed"cational 4b/!cti1!: !ting for both HBAg and anti-HBc off!r th! b!t cr!!ning for ac"t! h!patiti B inf!ction.
96
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 83: A 26-ye!-ol" ' co'e &o &$e o,,%ce #%&$ oe-#eek $%&o!y o, !%+$&-%"e" e! /%1 T$e /% o,&e #ke $%' / & %+$&3 " %c!ee % ee!%&y #$e $e c$e# ,oo"1 4e co& !ecll y e/%o"e o, /$!y+%&%1 4e "e%e $%+ y e! "%c$!+e3 % &e"e!e3 o! k% !$1 4e ee!c%e .y #%''%+ ,!eGe&ly & locl cl.1 4e % elly c&%e3 " e co"o'
Ra,ay H"nt yndro,! loopharyng!al n!"ralgia 4titi ,!dia in !arly tag! !,po,andib"lar /oint dyf"nction 4titi !xt!rna C!r",!n I,paction
Explanation:
h! ,ot li!ly diagnoi i r!f!rr!d otalgia d"! to t!,poro,andib"lar /oint #M% dyf"nction. Al$ay thin of r!f!rr!d otalgia $h!n a pati!nt pr!!nt $ith !ar pain0 b"t ha no ignificant or prior hitory of !ar probl!,. M dyf"nction i a co,,on ca"! of r!f!rr!d otalgia0 and pain aggra1at!d by ch!$ing0 along $ith pychog!nic grinding #br"xi,%0 f"rth!r "pport th! diagnoi. #Choic! A% Ra,ay H"nt yndro,! i a facial n!r1! paly that i ca"!d by h!rp! 5ot!r. 6ati!nt pr!!nt $ith l!ion of th! !xt!rnal !ar $ith or $itho"t ty,panic ,!,bran! in1ol1!,!nt 1!rtigo tinnit"0 and d!afn! d"! to g!nic"lat! ganglion in1ol1!,!nt. #Choic! B% loopharyng!al n!"ralgia i charact!ri5!d by a harp0 lancinating pain aociat!d $ith $allo$ing0 ch!$ing0 taling and ya$ning. hi condition ha alo b!!n aociat!d $ith ,"ltipl! cl!roi. #Choic! C% 4titi ,!dia i aociat!d $ith r!d"c!d ,obility of th! ty,panic ,!,bran! and in1ol1!,!nt of th! ,iddl! !ar ca1ity. #Choic! E% Altho"gh th! pati!nt+ hitory of fr!;"!nt $i,,ing incr!a! hi chanc! of ha1ing otiti !xt!rna0 th! phyical !xa,ination fail!d to find any !1id!nc! that can "pport thi diagnoi #!.g.0 pain on p"lling th! pinna or infla,!d !ar canal%. #Choic! % C!r",!n i,paction i 1!ry "nli!ly in thi !tting0 !p!cially inc! th! ty,panic ,!,bran! $a nor,ally 1iibl! and $itho"t ign of c!r",!n i,paction on phyical !xa,ination. Ed"cational 4b/!cti1!: 8"p!ct M yndro,! in a pati!nt $ith "nilat!ral and chronic pain of th! ,"cl! of ,atication. h! pain i d"ll and $or!n!d by ch!$ing. R!cogni5! th! charact!ritic radiation to th! !ar0 /a$0 and pot!rior c!r1ical r!gion.
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97
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 84: A 25-ye!-ol" ' /!ee& &o &$e e'e!+ecy "e/!&'e& ,&e! ""e oe& o, e &$!ee $o! +o3 ,ollo#e" .y % o! ee e/%o"e o, o'%&%+1 4e "e%e y "%!!$e o! ,ee!1 o! $o! +o3 $e &e ,!%e" !%ce le,& oe! ,!o' "%e! & C$%ee !e&!&1 4% /le % ?>'%3 .loo" /!e!e % 8>>@>'' 4+3 " &e'/e!&!e % 918 C (?@1@ )1 T$e!e !e o %+%,%c& ,%"%+ o /$y%cl e'%&%o1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely ce o, &$% /&%e&F y'/&o'; A. B. C. D. E.
8taphylococc" a"r!" Bacill" c!r!" Clotridi", p!rfring!n Clotridi", difficil! Ent!rotoxig!nic E. coil
Explanation:
or th! F8MLE0 "p!ct Bacill" c!r!" $h!n!1!r yo" r!ad abo"t a pati!nt $ho !at ric! and "b!;"!ntly d!1!lop na"!a and !1!r! 1o,iting. Bacill" c!r!" prod"c! a h!at-tabl! toxin in inad!;"at!ly r!frig!rat!d coo!d ric!. B!ca"! th! illn! i d"! to a pr!for,!d toxin0 y,pto, of na"!a and 1o,iting app!ar ;"icly aft!r con",ption of th! conta,inat!d food #b!t$!!n on! and ix ho"r aft!r ing!tion%. Aid! fro, pr!for,!d toxin0 ch!,ical irritant alo prod"c! abr"pton!t na"!a and !1!r! 1o,iting. #Choic! A% 8taphylococc" a"r!" toxin i pr!!nt in food "ch a dairy0 alad0 ,!at0 and !gg. 8y,pto, incl"d! na"!a0 1o,iting0 diarrh!a0 and abdo,inal pain. B!ca"! 8. a"r!" food poioning i alo d"! to a pr!for,!d toxin0 y,pto,-on!t i rapid0 ""ally $ithin on! to ix ho"r aft!r ing!tion. #Choic! C% Clotridi", p!rfring!n i a por!-for,ing organi,. It por! g!r,inat! in food "ch a ,!at0 po"ltry0 or gra1y. Ing!tion of "ch food r!"lt in $at!ry diarrh!a d"! to prod"ction of toxin in th! g"t. 8y,pto, on!t i lat!r than $ith pr!for,!d toxin #(-2& ho"r aft!r ing!tion%. Diarrh!a occ"r $ith ing!tion of a larg! n",b!r of organi,. #Choic! D% Clotridi", difficil! ca"! p!"do,!,brano" coliti aociat!d $ith th! "! of antibiotic. #Choic! E% Ent!rotoxig!nic E. coli i on! of th! ,ot co,,on ca"! of tra1!l!r+ diarrh!a0 b"t it i a rar! ca"! of diarrh!a in th! F8. Ed"cational 4b/!cti1!: Bacill" c!r!" ca"! na"!a and 1o,iting aft!r !ating ric!. 8y,pto, on!t i $ithin on! to ix ho"r.
98
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* Q NO 85: A t"dy $a don! to !1al"at! a n!$ !rological cr!!ning t!t for HI7 inf!ction. 20333 p!opl! $!r! rando,ly !l!ct!d fro, th! pop"lation0 cr!!n!d "ing th! n!$ t!t0 and cr!!n!d again "ing th! gold tandard #i.!.0 >!t!rn blot% to d!t!r,in! hih!r tr"! inf!ction tat!. h! finding ar! a follo$: r"! HI7 inf!ction tat! !t r!"lt S! 9o otal 6oiti1! 2&3 '3 *33 9!gati1! &3 )'3 (33 otal 2(3 (*3 2333 >hat i th! !niti1ity of thi n!$ !rological cr!!ning t!t A. B. C. D. E.
2&32(3 2&3*33 '3(*3 '3*33 2(32333
Explanation:
8!niti1ity and p!cificity ar! "!d to ,!a"r! a t!t+ 1alidity. 8!niti1ity i d!fin!d a th! proportion of di!a!d "b/!ct a,ong tho! $ith a poiti1! t!t r!"lt. 8p!cificity i d!fin!d a th! proportion of di!a!-fr!! "b/!ct a,ong tho! $ith a n!gati1! t!t r!"lt. Conid!r th! follo$ing * x * tabl!:
8!niti1ity @ 66X9 #AAXC% 8!niti1ity d!t!r,in! ho$ $!ll th! t!t id!ntifi! th! p!opl! $ith th! di!a!. It i ""ally th! firt t!t "!d0 li! a cr!!ning t!t $h!n th!r! i a p"blic h!alth thr!at. In oth!r $ord0 th! tr"! poiti1! rat! d!crib! th! !niti1ity of th! t!t. 8p!cificity @99X6 #DBXD% 8p!cificity d!t!r,in! ho$ $!ll th! t!t id!ntifi! th! h!althy p!opl!. In oth!r $ord0 th! tr"! n!gati1! rat! d!crib! th! p!cificity of th! t!t. A p!rf!ctly 1alid diagnotic t!t ho"ld ha1! !niti1ity and p!cificity !;"al to0 b"t thi i !ldo, poibl!. !n!rally0 th! ,or! !niti1! th! t!t0 th! l! p!cific and 1ic! 1!ra. In th! pr!!nt !xa,pl!0 th! !niti1ity i 2&32(3. Ed"cational ob/!cti1!: Kno$ ho$ to calc"lat! th! !niti1ity and p!cificity of a t!t.
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99
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 86: A 99-ye!-ol" 'le % "'%&&e" % &$e $o/%&l ,o! elec&%e c$olecy&ec&o'y1 4e $ o lle!+%e " "e%e &$e e o, y 'e"%c&%o1 4e 'oke " e lco$ol l%.e!lly1 A /!eo/e!&%e c$e& -!y $o# #%"ee" 'e"%&%' " MRI % o!"e!e"1 T$e MRI % $o# .elo#1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely ce o, $% /&$olo+y;
A. B. C. D. E.
Ath!rocl!roi Marfan+ yndro,! Bl"nt tra",a aaya"+ di!a! Mycotic inf!ction
Explanation:
h! MRI ho$ an aortic an!"ry, /"t dital to th! l!ft "bcla1ian art!ry. h! an!"ry, i locali5!d to th! d!c!nding aorta. In a yo"ng ,al! $ho pr!!nt $ith an an!"ry, of th! d!c!nding aorta0 th! ,ot li!ly ca"! i a hitory of prior bl"nt ch!t tra",a. h! do,inant pathophyiology !1!nt in bl"nt aortic in/"ry i d"! to d!c!l!ration $ith cr!ation of a h!ar forc! b!t$!!n a r!lati1!ly ,obil! part of th! thoracic aorta and an ad/ac!nt fix!d !g,!nt. h! ,a/ority of bl"nt in/"ri! to th! thoracic aorta ar! fro, ,otor 1!hicl! accid!nt. 6hyical !xa, in pati!nt $ith bl"nt aortic in/"ry ar! non-contrib"tory and th! in/"ry ,ay b! "p!ct!d fro, a $id!n!d ,!diatin", on a ch!t x-ray. Abo"t 23= of indi1id"al $ith aortic in/"ry ha1! a nor,al ch!t x-ray. If th! in/"ry i "p!ct!d0 a C can i diagnotic. 8o,! pati!nt ,ayb! dicharg!d on th! bai of a nor,al ch!t x-ray and pr!!nt lat!r $ith a p!"doan!"ry, of th! aorta. 8"rg!ry i r!;"ir!d to pr!1!nt r"pt"r! of th! an!"ry, #Choic! C%. #Choic! A% Ath!rocl!roi i th! ,ot co,,on ca"! of an!"ry, of th! d!c!nding aorta. Ho$!1!r0 th! pati!nt ar! ,"ch old!r0 ha1! a hitory of ,oing0 and p!riph!ral 1ac"lar di!a!. h!! d!c!nding an!"ry, ar! g!n!rally ay,pto,atic and ,ay b! id!ntifi!d on a ro"tin! ch!t xray. Rar!ly th!! an!"ry, ,ay i,ping! on th! r!c"rr!nt laryng!al n!r1! and prod"c! hoar!n!0 or co,pr! th! !ophag" and prod"c! dyphagia. C can or angiogra, ar! diagnotic. h! ,a/ority of pati!nt $ith d!c!nding aortic an!"ry, alo ha1! ignificant coronary art!ry di!a!. #Choic! B% Martan+ yndro,! i an a"too,al do,inant diord!r $ith 1ariabl! p!n!tranc!. It ha b!!n fo"nd to b! aociat!d $ith an abnor,al ynth!i of fibrillin0 a ,a/or contit"!nt of ,icrofibril. h! ,a/ority of pati!nt $ith Marfan+ yndro,! $ill pr!!nt $ith 100
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USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* an!"ry, of th! ac!nding aorta. Aociat!d finding ,ay b! aortic ann"lar dilatation that $ill ca"! aortic r!g"rgitation. 8"rg!ry i r!;"ir!d to r!plac! both th! aortic 1al1! and !ntir! ac!nding aorta. Marfan+ pati!nt ha1! a high!r incid!nc! of aortic di!ction than th! a1!rag! pati!nt. #Choic! D% aaya"+ art!riti co,,only afflict yo"ng f!,al! fro, th! 4ri!nt. h! diord!r i aociat!d $ith a prodro,! of f!1!r0 ,alai!0 and l!thargy. h! art!rial pathology i foc"!d on th! aorta and it branch!. h! aortic arch i ,or! fr!;"!ntly in1ol1!d and l!ad to y,pto, of global c!r!bral hypop!rf"ion or "pp!r !xtr!,ity cla"dication. An!"ry, ar! not !!n in aaya"+ di!a!. 8t!roid and balloon angioplati! ar! th! ,aintay of tr!at,!nt. #Choic! E% Mycotic an!"ry, r!"lt fro, a locali5!d inf!ction0 $hich ,ayb! blood born! or aociat!d $ith a locali5!d inf!ctio" proc!. It ,ay occ"r any $h!r!0 b"t i ,ot co,,on in th! f!,oral art!ry follo$!d by th! ac!nding aorta. h! ,ot co,,on pathog!n i 8taph a"r!" follo$!d by 8al,on!lla. 8yphilitic an!"ry, $!r! co,,on in th! pat d!cad! b"t ar! rar! today. 8yphilitic an!"ry, ar! g!n!rally confin!d to th! ac!nding aorta. 6ati!nt $ill pr!!nt $ith f!1!r0 chill0 p!t!chial in l!ion0 and plint!r h!,orrhag!. A C can i diagnotic. h! abo1! pati!nt do! not pr!!nt $ith any !1id!nc! of a prior inf!ction. Ed"cational 4b/!cti1!: D!c!nding aortic an!"ry, in a yo"ng ,al! i ""ally d"! to bl"nt tra",a to th! ch!t.
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 87: A 6 ye!-ol"-+%!l #%&$ $e!e"%&!yF /$e!ocy&o% % c$e"le" ,o! /leec&o'y1 S$e # /!e%oly '+e" #%&$ ,ol&e &$e!/y " occ%ol .loo" &!,%o3 .& $e! e'% .ec'e !e,!c&o!y &o 'e"%cl '+e'e& loe1 Be,o!e &$e o/e!&%o3 $e % &ol" &$& $e #%ll $e e$ce" !%k o, "eelo/%+ /e'ococcl e/%1 S$e &$e k3 <4o# lo+ #%ll &$% !%k l&;= W$& % &$e .e& !e/oe &o $e! Ge&%o; A. B. C. D. E.
* $!! Fp to ' ,onth Fp to * y!ar Fp to 23 y!ar Mor! than 23 y!ar
Explanation:
H!r!ditary ph!rocytoi i an a"too,al do,inant diord!r. It i charact!ri5!d by a lac of p!ctrin in th! r!d c!ll ,!,bran!0 $hich ca"! th! c!ll to b!co,! ph!r!0 int!ad of b!ing nor,al0 fl!xibl! and d"rabl! biconca1! dic. h! poorly fl!xibl! ph!rical c!ll ar! th" "nabl! to pa thro"gh th! ,all f!n!tration in th! pl!nic r!d p"lp0 and h!,olyi ta! plac! $h!n th! r!d c!ll ar! trapp!d $ithin th! pl!!n. h! tr!at,!nt for ,ot pati!nt in1ol1! "pporti1! car! $ith oral folic acid and blood tranf"ion d"ring p!riod of !xtr!,! an!,ia. 8pl!n!cto,y i conid!r!d if pati!nt ha1! ,od!rat! to !1!r! ph!rocytoi0 or ar! r!fractory to ,!dical ,anag!,!nt. h! b!n!fit of pl!n!cto,y ,"t b! balanc!d againt th! i,,!diat! and long-t!r, ri of th! proc!d"r!. Lif!-thr!at!ning an!,ia and th! n!!d for r!g"lar tranf"ion ,ayb! abolih!d by pl!n!cto,y0 altho"gh a ,ild d!gr!! of an!,ia ""ally p!rit. I,,!diat! ri #!.g.0 h!,orrhag!0 potop!rati1! inf!ction0 in/"ry to n!arby organ% ar! infr!;"!nt. h! ,ot f!ar!d long-t!r, co,plication i o1!r$h!l,ing !pi $ith !ncap"lat!d bact!ria0 ,ot co,,only 8tr!ptococc" pn!",onia!. 8t"di! ha1! ho$n that th! ri for pn!",ococcal !pi i pr!!nt "p to <3 y!ar and probably long!r aft!r pl!n!cto,y. o d!cr!a! thi ri0 c"rr!nt r!co,,!ndation call for th! ad,initration of antipn!",ococcal0 Ha!,ophil"0 and ,!ningococcal 1accin! !1!ral $!! b!for! th! op!ration0 and daily oral p!nicillin prophylaxi for thr!! to fi1! y!ar follo$ing pl!n!cto,y or "ntil ad"lthood #for p!diatric pati!nt%. In 1i!$ of r!port!d d!ath fro, !pi "p to <3 y!ar or ,or! aft!r pl!n!cto,y0 a ca! can b! ,ad! for lif!ti,! p!nicillin prophylaxi. Alt!rnati1!ly. antibiotic can b! ,ad! a1ailabl! at ho,! for i,,!diat! tr!at,!nt of any ignificant f!1!r. Ed"cational 4b/!cti1!: 8t"di! ha1! ho$n that th! ri for !pi i pr!!nt "p to <3 y!ar and probably long!r alt!r pl!n!cto,y. C"rr!nt r!co,,!ndation tat! that pati!nt ho"ld r!c!i1! anti-pn!",ococcal0 Ha!,ophil"0 and ,!ningococcal 1accin! !1!ral $!! b!for! th! op!ration0 and daily oral p!nicillin prophylaxi for thr!! to fi1! y!ar follo$ing pl!n!cto,y. Extr!,!ly i,portant ;"!tion for th! F8MLE t!p-*
102
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 88: A 5?-ye!-ol" ' co'e &o &$e /$y%c% .ece o, "y!%3 !%!y !+ecy3 " ,!eGecy1 4e lo co'/l% o, $e'&!%3 oc&!%3 "ec!ee" ,o!ce o, &!e'3 " ,eel%+ o, %co'/le&e o%"%+1 T$ee y'/&o' $e .ee /!ee& ,o! 'o!e &$ 'o&$1 o! &$e /& ,e# "y $e $ .ee e/e!%ec%+ "ll3 o-!"%&%+ /!/.%c /%1 4e $ lo .ee $%+ lo#-+!"e ,ee! " 'l%e ,o! &$e /& co/le o, "y1 4e $ .ee &k%+ l+e%c ,o! o&eo!&$!%&% o, $% !%+$& kee ,o! 'o!e &$ 8> ye!1 4e $ 0>-/ck-ye! $%&o!y o, c%+!e&&e 'ok%+ " "oe o& e lco$ol o! "!+1 Rec&l e'%&%o $o# 'oo&$3 ,%!' el!+e'e& o, &$e /!o&&e #%&$o& %"!&%o o! y''e&!y1 Ne!olo+%cl e'%&%o $o# o .o!'l%&%e1 U!%ly% $o# $e'&!% #%&$ %o'o!/$%c !e" .loo" cell1 L.o!&o!y &"%e $o# e!' c!e&%%e o, 5 '+"L3 " PSA o, 2 +'L1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely e/l&%o ,o! &$% /&%e&F y'/&o'; A. B. C. D. E.
B!nign protatic hyp!rplaia Carcino,a of bladd!r Carcino,a of protat! Fr!thral trict"r! 9!"rog!nic bladd!r
Explanation:
h! abo1! pati!nt ha pr!!nt!d $ith irritati1! and obtr"cti1! 1oiding y,pto,. 8"ch y,pto, ,ay b! prod"c!d by ,"ltipl! ca"! li! b!nign protatic hyp!rplaia0 bladd!r canc!r0 protat! canc!r0 "r!thral trict"r!0 n!"rog!nic bladd!r and "rinary tract inf!ction. h!r!for!0 in all "ch pati!nt0 car!f"l hitory0 !xa,ination and c!rtain lab t!t ho"ld b! p!rfor,!d to find o"t th! !xact ca"! of 1oiding co,plaint. B!nign protatic hyp!rplaia can prod"c! both irritati1! and obtr"cti1! 1oiding y,pto,0 b"t pr!!nc! of b!nign protatic hyp!rplaia i poorly corr!lat!d $ith 1oiding y,pto,. 6r!!nc! of a fir,0 !nlarg!d protat! on r!ctal !xa,ination do! not al$ay ,!an that 1oiding y,pto, ar! d"! to an !nlarg!d protat! a ,ot pati!nt $ith protat! !nlarg!,!nt ar! ay,pto,atic. h!r!for!0 all th! oth!r ca"! ho"ld b! r"l!d o"t b!for! attrib"ting y,pto, to b!nign protatic hyp!rplaia. 6ati!nt $ith b!nign protatic hyp!rplaia ""ally do not ha1! h!,at"ria0 "prap"bic pain and yt!,ic f!at"r! #Choic! A%. 6r!!nc! of h!,at"ria $ith irritati1! or 1oiding y,pto, ho"ld alar, th! phyician to th! poibility of bladd!r canc!r. Bladd!r ton! ,ay alo prod"c! h!,at"ria. 6r!!nc! of "prap"bic pain ,ay alo occ"r $ith bladd!r canc!r. If bladd!r canc!r i ad1anc!d0 it ,ay prod"c! "prap"bic pain d"! to in1ol1!,!nt of p!ri1!ical n!r1! or d"! to obtr"ction of bladd!r o"tl!t and "rinary r!t!ntion. 8yt!,ic f!at"r! app!ar $h!n bladd!r canc!r i ad1anc!d or ,!tatatic. hi pati!nt ha a long hi tory of analg!ic "! that i a ri factor for th! d!1!lop,!nt of bladd!r canc!r. Cigar!tt! ,oing i anoth!r ri factor. Ba!d on all th!! finding0 thi pati!nt i ,ot li!ly "ff!ring fro, bladd!r canc!r #Choic! B%. #Choic! C% 6ati!nt $ith protat! canc!r ha1! ind"ration of th!ir gland on r!ctal !xa,ination and 68A i gr!at!r than & ng,l in "ch pati!nt.
__________________________________________________________ 103
USMLE WORLD STEP 2 CK (INTERNAL MEDICINE) *Block 2* #Choic! D% 6ati!nt $ith "r!thral trict"r! ""ally gi1! a hitory of "r!thral tra",a or "r!thral intr",!ntation. H!,at"ria i "nli!ly in trict"r!. #Choic! E% 6ati!nt $ith n!"rog!nic bladd!r ha1! abnor,al n!"rological !xa,ination. h!r! ,ay b! a hitory of n!"rological di!a!0 diab!t!0 tro! or bac in/"ry. Ed"cational 4b/!cti1!: 6r!!nc! of h!,at"ria in a pati!nt $ith irritati1! or obtr"cti1! 1oiding ho"ld al!rt th! phyician to th! poibility of bladd!r canc!r.
104
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 89: A 65-ye!-ol" .e"!%""e #o' % .!o+$& % #%&$ co'/l%& o, #e%+$& lo #eke " 'l%e1 4e! /& 'e"%cl $%&o!y %cl"e c$!o%c o.&!c&%e /l'o!y "%ee ("%+oe" ,%,&ee ye! +o) " $y/e!&e%o o,&e ye!F "!&%o1 S$e G%& 'ok%+ &#o ye! +o3 .& /!e%oly 'oke" &$!ee /ck o, c%+!e&&e "%ly %ce $e # 2> ye! o, +e1 4e! %&l %+ !e &.le1 4e! /$y%cl e'%&%o !eel ee!e #eke % $e! /!o%'l 'cle3 " lo o, "ee/ &e"o !e,lee1 C$e& -!y $o# !%+$& //e! l+ ' #%&$ 'e"%&%l ly'/$"eo/&$y1 W$%c$ o, &$e ,ollo#%+ % &$e 'o& l%kely ce o, $e! #eke; A. B. C. D. E.
A"toantibodi! againt pot ynaptic r!c!ptor I,,"n! ,!diat!d ,"cl! infla,,ation Fpp!r and lo$!r ,otor n!"ron d!g!n!ration M"ltic!ntric C98 infla,,ation and d!,y!lination Antibodi! to 1oltag! gait!d calci", chann!l
Explanation:
hi pati!nt+ hitory #i.!.0 h!a1y ,oing0 $!ight lo% and phyical finding #i.!.0 proxi,al ,"cl! $!an!0 ,alai!0 l"ng ,a% ar! "gg!ti1! of Myath!nic or La,b!rt-Eaton yndro,!0 $hich can occ"r in aociation $ith ,all c!ll carcino,a of th! l"ng. La,b!rt-Eaton yndro,! i ca"!d by a"toantibodi! that ar! dir!ct!d againt th! 1oltag!-gat!d calci", chann!l in th! pr!ynaptic ,otor n!r1! t!r,inal. hi l!ad to th! d!f!cti1! r!l!a! of ac!tylcholin!0 th!r!by l!ading to proxi,al ,"cl! $!an!. El!ctrophyiological t"di! confir, th! diagnoi #th! ,"cl! r!pon! to ,otor n!r1! ti,"lation ho"ld incr!a! $ith r!p!titi1! ti,"lation%. r!at,!nt conit of pla,aph!r!i and i,,"no"ppr!i1! dr"g th!rapy. #Choic! A% A"toantibodi! againt potynaptic r!c!ptor ca"! ,yath!nia gra1i. R!d"ction of potynaptic ac!tylcholin! r!c!ptor l!ad to ,"cl! $!an!. h! ,"cl! $!an! i pro1o!d by r!p!titi1! or "tain!d "! of th! ,"cl! in1ol1!d0 "nli! ,yath!nic yndro,!. D!!p t!ndon r!fl!x! ar! ""ally pr!!r1!d0 and ,ay b! o,!$hat bri in clinically $!a ,"cl!. #Choic! B% I,,"n!-,!diat!d ,"cl! infla,,ation "gg!t poly,yoiti. It pr!!nt a proxi,al $!an! charact!ri5!d by diffic"lty ac!nding and d!c!nding tair0 co,bing hair0 n!!ling do$n0 !tc. It i not aociat!d $ith ab!nt r!fl!x!. #Choic! C% Fpp!r and lo$!r ,otor n!"ron d!g!n!ration "gg!t a,yotrophic lat!ral cl!roi. It initially pr!!nt $ith b"lbar y,pto,0 follo$!d by "pp!r and lo$!r li,b $!an!. #Choic! D% M"ltic!ntric C98 infla,,ation and d!,y!lination ar! indicati1! of ,"ltipl! cl!roi #M8%. M8 i rar! in p!opl! yo"ng!r than 0G and old!r than '3 y!ar of ag!. h! claic pr!!ntation incl"d! !nory lo0 paticity0 c!r!b!llar y,pto,0 optic n!"riti0 d!pr!ion and ,any oth!r n!"ropychological dyf"nction. Ed"cational 4b/!cti1!: Eaton-La,b!rt yndro,! i aociat!d $ith ,all c!ll carcino,a of th! l"ng0 and r!"lt fro, a"toantibodi! dir!ct!d againt th! 1oltag!gat!d calci", chann!l in th! pr!ynaptic ,otor n!r1! t!r,inal.
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USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 90: A ce-co&!ol &"y # co"c&e" &o e &$e !el&%o$%/ .e&#ee &'/o e " &o%c $ock y"!o'e (TSS)1 T$e o"" !&%o ,o! &'/o e co'/!%+ &$e /&%e& #%&$ TSS " &$e $el&$y .:ec& (co&!ol) # 51> (/ >1>>8)1 T$e &$o! cocl"e" &$& &$e !%k o, TSS % 5&%'e $%+$e! % &'/o e!1 T$e cocl%o % l%" %, #$%c$ o, &$e ,ollo#%+ '/&%o % &%,%e"; A. B. C. D. E.
h! h! h! 88 h!
a,pl! i5! i big odd ratio i highly tatitically ignificant confid!nc! int!r1al for th! odd ratio i tight i a rar! di!a! !xpo"r! i not aociat!d $ith th! di!a!
Explanation:
Ca!-control t"di! ar! 1!ry pop"lar in !xploring an !xpo"r!-di!a! aociation0 b!ca"! th!y ar! r!lati1!ly ch!ap and l! ti,!-con",ing than cohort t"di!. 4n! of th! ,a/or dra$bac of ca!-control t"di! i th! fact that th! ri cannot b! d!ri1!d dir!ctly fro, th!ir r!"lt. Expo"r!-odd ratio i th! ,!a"r! of aociation in ca!-control t"di!. It co,par! th! odd of !xpo"r! in ca! to th! odd of !xpo"r! in control. Iti 94 th! a,! a r!lati1! ri. R!lati1! ri can b! calc"lat!d in follo$-"p t"di! by co,paring th! ri in !xpo!d indi1id"al to th! ri in "n!xpo!d indi1id"al. Dir!ct calc"lation of th! r!lati1! ri i not poibl! in ca!-control t"di!0 b!ca"! th! t"dy d!ign do! not incl"d! follo$ing p!opl! o1!rti,!. 9!1!rth!l!0 th! r!lati1! ri can o,!ti,! b! approxi,at!ly !;"al to th! odd ratio. If th! pr!1al!nc! of th! di!a! i lo$ !xpo"r!0 th! odd ratio approxi,at! th! r!lati1! ri. hi tat!,!nt i call!d th! rar! di!a! a",ption+ and r!pr!!nt on! of th! f"nda,!ntal !pid!,iologic conc!pt. #Choic! A0 B and C% Incr!aing th! a,pl! i5! $o"ld d!cr!a! th! p 1al"! for th! odd ratio and ,a! th! confid!nc! int!r1al tight!r. h! pr!ciion of th! !ti,at! $o"ld incr!a! b"t0 that fact do! not aff!ct th! approxi,ation of th! odd ratio to th! r!lati1! ri. #Choic! E%h! r!"lt of th! t"dy "gg!t that th! !xpo"r! i aociat!d $ith th! di!a!. Ed"cational 4b/!cti1!: If th! o"tco,! of a ca!-control t"dy i not co,,on in th! pop"lation0 th! odd ratio i clo! to th! r!lati1! ri.
106
__________________________________________________________
USMLE WORLD STEP 2 CK 2*
(INTERNAL MEDICINE) *Block
Q NO 91: A 2@-ye!-ol" ' #%&$ $%&o!y o, %&!eo "!+ .e /!ee& #%&$ $%+$-+!"e ,ee!3 !%+o!3 " c$%ll ,o! &$e l& &#o "y1 4e $ o $%&o!F o, /!e-e%&%+ $e!& "%ee3 .& # "'%&&e" &o &$e $o/%&l % 'o&$ +o ,o! celll%&% o, &$e !'1 4% &e'/e!&!e % 0>1> C (8>0 )3 /le % 88>'%3 !e/%!&%o !e 22'%3 " .loo" /!e!e % 88>65 '% 4+1 O!o/$!y % cle!1 L+ !e cle! &o cl&&%o1 A e# $oloy&ol%c '!'! % $e!" & &$e le,& eco" %&e!co&l /ce " lo+ &$e le,& &e!l .o!"e!1 4% .loo" % "!# " e& ,o! cl&!e1 W$& % &$e 'o& //!o/!%&e e'/%!%c &%.%o&%c &$e!/y ,o! &$% /&%e&; A. B. C. D. E.
7anco,ycin and g!nta,icin 9afcillin and g!nta,icin C!fa5olin and g!nta,icin 9afcillin and c!f!pi,! 6!nicillin and clinda,ycin
Explanation:
Any I7 dr"g ab"!r $ith f!1!r and n!$-on!t ,"r,"r ho"ld b! d!!,!d to ha1! inf!cti1! !ndocarditi #IE% "ntil pro1!n oth!r$i!. I7 dr"g ab"! i a ri factor for IE0 and th! ""al ca"ati1! organi, in thi it"ation i 8taphylococc" a"r!". h! ,ot appropriat! !,piric antibiotic r!gi,!n in "ch a it"ation i 1anco,ycin X g!nta,ycin0 b!ca"! thi co1!r 8taphylococci 0 Ent!rococci and 8tr!ptococci. "rth!r,or!0 b!ta-lacta, antibiotic ar! yn!rgitic $ith a,inoglycoid!. h! oth!r antibiotic choic! do not co1!r all th! abo1!-,!ntion!d organi,. #Choic! B0 C0 D0 and E% If th! pati!nt $!r! not an I7 dr"g ab"!r0 th!n g!nta,icin pl" !ith!r nafcillin or c!fa5olin $o"ld ha1! b!!n a r!aonabl! choic!. M!thicillin-r!itant 8taphylococc" a"r!" #MR8A% inf!ction ar! on th! ri!. h"0 !,piric antibiotic th!rapy ho"ld co1!r MR8A. 6!nicillin i not a good choic! b!ca"! ,or! than = of 8taphylococc" a"r!" train ar! p!nicillin-r!itant. Clinda,ycin can co1!r o,! MR8A inf!ction b"t ho"ld not b! "!d for !ndocarditi. 8in and oft ti"! inf!ction can b! tr!at!d $ith clinda,ycin alon!. Ed"cational 4b/!cti1!: Inf!cti1! !ndocarditi i !p!cially co,,on in I7 dr"g ab"!r. It can b! fatal if initial !,piric tr!at,!nt #i.!.0 1anco,ycin X g!nta,icin for I7 dr"g ab"!r% i d!lay!d.
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