NBME Form 31 Incorrects Flashcards
2wk history of pain in R leg just below the knee of 14yr old boy. XR shows large, semi-Ca mass that erodes the medullary canal of the tibia, infiltrates the cortex, and extends into the nearby soft tissues.
osteosarcoma.
predominately affects the LONG bones: tibia, femur
erodes thru cortex givin “sunburst” periosoteal rxn, elevation of periosteum> Codman tri
histology: lesion w/ primitive cells in lace-like meshwork of bone with mitoses; osteoblast-like mesencyhmal cells that make osteoid.
aggressive, poor prognosis.
what is the most common primary bone tumor to affect the vertebrae?
osteoblastoma, benign; no response to aspirin.
vertebrae are common MET sites for breast & prostate cancer> look for pain worse in the night/sclerotic lesions
MOA of ketoconazole?
inhibition of lanosterol->ergosterol in the fungal cell wall by 14ademethylase.
what is the common cause of tinea cruris?
trichophyton rubrum
tinea cruris> “jock itch”, crotch and peritoneum.
what is the typical treatment for tinea cruris?
topical azole antifungal> clotrimazole
chronic hep C pt, 2wk hx weakness/rash on legs. 2+ edema, pupuric rash over the extremities. C3/C4 decreased. UA dysmorphic RBC, no casts. creatinine inc.
essential mixed cryoglobulinemia> cryoglobulins are IGs that precipitate out of the serum. triad: weakness, arthralgias, palpable purpura.
risk factors: chronic Hep C/B, HIV, malaria, EBV; chronic inflame- SLE, Sjogren; lymphoproliferative multiple myeloma.
causes deposition of immune complexes (HS3) in BV> leukocytoclastic vasculitis> can manifest as purpura, end organ dysfunction= renal failure/nephritic/nephrotic syndromes.
49yr old with poorly controlled HTN in ER with SOB. Ran out of meds 5 days ago. BP 240/120, pulse 98, r 32, 86% O2. Loud S4. b/l crackles on lung fields. CXR pulm edema. Diagnosis?
congestive heart failure> presenting as decompensated heart failure.
pathophyis> long-standing, uncontrolled HTN> ventricular hypertrophy> dec compliance, dec filling>diastolic dysfxn.
with a loud S4 (gallop in late diastole), most likely diastolic dysfunction HF. inc atrial P, ventricular hypertrophy, as the LA attempts to overcome stiff/noncompliant LV.
echocardiography shows thick LV muscle tissue. what is the underlying condition?
HTN> LV hypertrophy as a result of constant work against the incr afterload> impaired LV relaxation, inc diastolic P> LA enlargement> heart failure over time.
mitral stenosis findings on ECG
LA hypertrophy, reduced LV SV
opening snap with diastolic rumble murmur
23yr F w/ chronic sinusitis. Needs to drain L maxillary sinus–what is the placement of the cannula?
at middle meatus, at the hiatus semilunaris.
pt has bacterial sinusitis 2/2 viral URI; dull pain aggravated by leaning forward.
complications: orbital cellulitis, cavernous sinus thrombosis, meningitis.
the anterior portion of the piriform aperture is commonly opened during what procedure?
functional septoplasty–enhances airflow thru nose
// ant portion of aperture opens into the cartilaginous anterior nasal vestibule> lateral to maxillary bones, nasal septum medial.
sphenoethmoidal recess is found at?
the superior aspect of the nasal cavity– superior and posterior to the superior nasal concha» opens into the sphenoid sinus– common pathway for the trasnsphenoidal approach to pit gland
what is immediately anterior to the torus tubarius?
opening of the eustachian tube into the nasopharynx» connects posterior nasopharynx to the middle ear» causing acute otitis media.
what is immediately inferior to the anterior margin of the superior conchae?
superior nasal meatus–which communicates with the posterior ethmoid cells.
44yr M with 2 month history of dry mouth, constipation, inability to have erection, progressive fatigue. neuro exam shows weakness of alot muscles, absence of all stretch reflexes; normal sensation. CXR shows R lung mass. Labs show antibodies directed against PQ calcium channels. Why neuro findings?
impaired Ach release at NMJ, limiting cell depol, proximal muscle weakness» not dec excitation contraction coupling. pt has Lambert-Eaton paraneoplastic syndrome 2/2 small cell lung cancer.
LE= extended use makes better, gradual accumulation of Ach in synapse= better depol. PRESYNAPTIC NMJ. (MG is postsynpatic Ach NMJ)
male newborn has multiple features suggestive of Downs syndrome. Chromosomal analysis is ordered. What do you tell the parents?
The newborn has features of Downs, a chromosomal test is ordered» NOT the newborn has some unusual features on exam, and a test has been ordered to help determine diagnosis.
Doc should address objective findings by explaining diff diagnosis and the next steps in simple language in small pieces> honor autonomy w/ relevant information–do not protect patient from distressing news, allow them to process info in small pieces.
what are the symptoms of cavernous sinus thrombosis?
i/l orbit pain, sinusitis, proptosis, periorbital edema, impaired eye movement/pupil reactivity.
» CN 3,4,5a,5b,6 transverse the sinus
what patients are at risk for developing ophthalmic artery embolism?
carotid/cardiac valvular disease pt> central retinal artery occlusion» acute, painless vision loss and diminished visual acuity, pale fundus (preserved foveal color), afferent pupillary defect.
*****admit to stroke center for emergent eval
48yr man w/ 30yr PMH DM1 w/ sudden onset double vision. L eye weakness abduction. What is the development of double vision ?
diabetic mononeuropathy.
microvascular damage commonly affects the abducens n> presents as esotropia, u/l abduction defect, diplopia in horizontal gase, hypotropia. most pts have resolution of symptoms with tx of underlying cause.
**important to rule out stroke, ICP, vasculitis, optic neuropathy,
24yr woman with increased ROM in her joints. 6ft tall, 130lb, BMI 18. Pectus excavatum. Cardio exam reveals new diastolic murmur. What is the most likely cause?
aortic insufficiency» pt has Marfan syndrome, impaired collagen synthesis.
subsequently leads to an incr LV EDV» eccentric hypertrophy of the LV, progressive LV systolic dysfxn
when would you see a systolic murmur in a Marfan pt?
myxomatous degeneration of mitral value» mitral insufficiency (mitral valve prolapse)» presents with holosystolic murmur.
24yr F w/ 3day history of vaginal discharge w/ itching. Currently tx with ciprofloxacin for cystitis. Vaginal area now presents with thick, white discharge. What is the most likely caused organism?
candida albicans> pt has vaginal pruritis, thick white discharge with antibiotic tx> vulvovaginitis from Candida. “cottage cheese” appearance
neg KOH testing, normal vaginal pH, no trichomonads on wet mount
risk factors: those on antibiotics, contraceptives (oral & intrauterine), immunocompromised, DM
tx: antifungals (topical clotimazole, oral fluconazole)
N. gonorrhea is gram neg that can present with cervicitis, PID, Fitz-Hugh-Curtis, urethritis, vaginitis. How can you tell diff btw gonorrhea vs. candida?
the discharge»gonorrhea will present with mucopurulent discharge, pruritis, and be generally asymptomatic vs candida is thicker, white discharge.
76yr M in ER with inability to urinate. Markedly enlarged prostate, u/s shows large kidneys with dilated calyces. PO2 is 90mmHg. What is the suspected ABG?
pt has BPH> leading to hydronephrosis, obstructive uropathy> leading to volume expansion +RAAS> HTN» metabolic acidosis, non-anion gap via urinary acidification (generally unless uremia or another concomitant anion gap issue). will be compensated w/ resp alk, tachypnea» near normal pH.
56yr M w/ 2 month hx bloody cough. CT shows 4cm mass in RUL that’s obstructing SVC. Blood returns to heart via?
internal mammaries & intercostal veins.
when SVC obstructed, can drain into the IVC via internal mammary v with sup/inf epigastric v.
the azygos/hemiazygous v drain posterior intercostal/bronchial v> via lumbar venous system to IVC
long thoracic venous communicates with femoral & verterbral v> to IVC.
pt will develop venous congestion head/neck/upper extremities= SVC syndrome regardless of collaterals tho
what veins are the main venous drainage of the head?
jugular & subclavian v.
external jugular v> subclavian>internal jugular>brachiocephalic> L & R merge to make SVC.
43yr F w/ 2 mon history of intermittent abdominal pain, esp after fatty meals, localized to RUQ. u/s shows cholelithiasis. MOA of ursodiol?
decreased cholesterol secretion into bile by 40-60%, dec absorb into the gut; ursodiol=ursodeoxycholic acid (generally second line to surgery)
pt has all characteristics of cholelithiasis: middle-aged female, RUQ pain after fatty meals. risk factors: obesity, advanced age, estrogen tx, rapid weight loss, Crohn’s, 4F’s
**statins generally have lower gallstone risk; fibrates (inhibit chol 7a hydroxylase) have most risk–> end up having supersaturated cholesterol with inhibited bile acid synthesis.
32yr F with intermittent chest pain “not severe, just kinda annoying”. Mother died of sudden MI ~50s. Midsystolic click at 5th intercostal space on L midclavicular line. What cardio thing is happening?
mitral valve prolapse> generally asympt, but have palpitations, chest pain, dyspnea.
midsystolic click +- late systolic murmur of mitral regurg.
more common in females, most common cause is myxomatous degeneration, chorda tendinea rupture, mitral annular disjunction> where the mitral annulus becomes partially detached.
***degeneration results in thickened mitral valve leaflets with accumulation of fibrous & mucoid material» commonly associated w/ Marfan, PKD, SLE, polyarteritis nodosa.
ASD murmur
fixed, split S2 with low grade physiological ejection murmur
L>R shunt with abnormal flow of blood from LA to RA> volume overload R heart
Bicuspid aortic valve murmur
bicuspid aortic valve> aortic stenosis> crescendo-decrescendo systolic murmur @ R upper sternal border
Tricuspid regurg murmur
holosystolic murmur best heard in L lower sternal border» esp common with severe pulm HTN/infective endocarditis of IV user
what is the most common skin cancer?
basal cell carcinoma> originating from basal layer of epidermis, low met potential
typically: pink, pearly papules/nodules with rolled borders & central ulceration in sun exposed areas of head/neck.
tx: surgical excision removal, Mohs surgery
associated w/ mutations in hedgehog pathway of p53…primary risk factor is UV exposure.
