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Behavioral HealthPsychiatryMediumS1-BH-3U5M

Schneider first-rank symptoms

A 22-year-old man believes his thoughts are broadcast, that a microchip controls his actions, and hears two voices talking about him. Symptoms have lasted 8 months with withdrawal.

Why were these 'first-rank symptoms' considered important?

  1. They indicate genetic rather than environmental etiology
  2. They were considered highly suggestive of schizophrenia when present in the absence of organic causes
  3. They are pathognomonic for schizophrenia and exclude all other diagnoses
  4. They indicate a more severe prognosis than other psychotic symptoms
  5. They respond exclusively to typical antipsychotics
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Behavioral HealthBehavioral Science / DevelopmentEasyS1-BH-PJ2A

Piaget conservation

A 4-year-old watches equal amounts of juice poured into a tall thin glass and a short wide glass, yet still insists the tall glass holds more.

This shows that the child does not yet understand which concept?

  1. Object permanence
  2. Centration
  3. Conservation
  4. Animism
  5. Artificialism
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Behavioral HealthBehavioral ScienceEasyS1-BH-BD5R

Transition difficulties

A 5-year-old boy becomes aggressive only at transitions. He hits classmates when cleanup is announced and has tantrums when moving from playground to classroom, but behaves well otherwise.

Which intervention would help most?

  1. Visual schedule and transition warnings
  2. Removal of playground privileges
  3. One-on-one aide assignment
  4. Behavioral reward chart
  5. Time-out after each aggressive incident
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Behavioral HealthPharmacologyEasyS1-BH-BC5V

Thiazide and lithium

A 38-year-old woman on lithium has coarse tremor, ataxia and confusion after starting HCTZ; her level is 2.0.

What is the mechanism?

  1. Inhibition of hepatic metabolism via CYP3A4
  2. Increased proximal tubular reabsorption due to volume depletion
  3. Displacement from plasma protein binding
  4. Inhibition of renal excretion via organic anion transporters
  5. Direct additive neurotoxicity
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Behavioral HealthEthicsEasyS1-BH-7PAK

Social media boundaries

A physician gets a LinkedIn connection request from a current patient, who says it is for professional networking.

What is the most appropriate response?

  1. Accept but limit interaction to professional topics
  2. Accept to avoid seeming rude
  3. Decline and explain professional boundary policies
  4. Ignore the request without explanation
  5. Report the patient for inappropriate behavior
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CardiovascularPathologyEasyS1-CV-BNK5

Physiologic splitting of S2

A healthy 28-year-old medical student listens to his own heart and notices that S2 splits during inspiration.

What causes the inspiratory split?

  1. Decreased right ventricular ejection time
  2. Increased right ventricular ejection time
  3. Earlier mitral valve closure
  4. Later tricuspid valve closure
  5. Increased left ventricular ejection time
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CardiovascularPhysiologyMediumS1-CV-B2RR

Fluid challenge

A 28-year-old man has a pulmonary artery catheter. Wedge pressure is 8 mmHg and cardiac output 5 L/min. After fluids, wedge pressure rises to 12 mmHg and cardiac output to 6.5 L/min.

What does this response show?

  1. Systolic dysfunction
  2. Valvular disease
  3. Diastolic dysfunction
  4. Normal ventricular function
  5. Pericardial disease
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CardiovascularBiochemistryMediumS1-CV-BK5U

Noonan LEOPARD

A 6-year-old boy has many lentigines, short stature and pulmonary stenosis. His father looks similar.

Which gene mutation is most likely?

  1. PTEN
  2. KIT
  3. PTPN11
  4. NF1
  5. TSC1
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CardiovascularPharmacologyHardS1-CV-BXVY

Dual-pathway rivaroxaban in CCD

A man with diabetes and non-revascularizable chronic coronary disease has frequent angina on optimal therapy and no bleeding risk factors.

Which antithrombotic change best reduces major cardiovascular events?

  1. Add vorapaxar 2.08 mg daily
  2. Switch aspirin to prasugrel 10 mg daily
  3. Add low-dose rivaroxaban 2.5 mg orally twice daily to aspirin (dual pathway inhibition)
  4. Increase aspirin to 325 mg daily
  5. Add clopidogrel 75 mg daily to aspirin
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CardiovascularMicrobiologyMediumS1-CV-K566

Nutritionally variant streptococci

A 62-year-old woman with endocarditis has blood cultures growing nutritionally variant streptococci (Abiotrophia or Granulicatella).

Which culture change is needed for growth?

  1. High salt concentration
  2. Incubation at 42°C
  3. Anaerobic atmosphere
  4. Acidic pH
  5. Addition of pyridoxal (vitamin B6)
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EndocrinePhysiologyEasyS1-EN-2K5X

PCOS and weight loss

A 30-year-old woman with PCOS and BMI 33 loses much less weight than her sister without PCOS on a similar calorie cut.

Which factor best explains her difficulty?

  1. Decreased androgen levels
  2. Insulin resistance reducing lipolysis
  3. Higher resting metabolic rate
  4. Increased brown adipose tissue
  5. Enhanced insulin sensitivity
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EndocrineImmunologyEasyS1-EN-SZ48

Graves ophthalmopathy

A 28-year-old woman with Graves disease on methimazole has worsening eye bulging and double vision. MRI shows enlarged extraocular muscles.

Which antigen is targeted in thyroid eye disease?

  1. Collagen type II in orbital tissue
  2. Melanocytes in the orbit
  3. Acetylcholine receptor on eye muscles
  4. TSH receptor on orbital fibroblasts
  5. Vascular endothelium in orbital vessels
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EndocrinePathologyEasyS1-EN-S7T7

Sarcoidosis hypercalcemia

A 40-year-old man has polyuria, thirst, a dry cough and bilateral hilar adenopathy. Calcium is 11.5 mg/dL, PTH is suppressed, 1,25-(OH)2 vitamin D is high, 25-OH vitamin D is normal and ACE is elevated. Transbronchial biopsy shows noncaseating granulomas.

What is the main cause of his hypercalcemia?

  1. Decreased renal calcium excretion from thiazide-like effect of granulomatous nephritis
  2. Osteoclast-activating factor release from lymphocytes infiltrating bone marrow
  3. Extrarenal 1-alpha-hydroxylase activity in activated macrophages within granulomas
  4. PTH-related peptide secretion from granulomatous tissue acting on bone and kidney
  5. Increased intestinal calcium absorption from excessive dietary vitamin D intake
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EndocrinePharmacologyEasyS1-EN-BVYV

Pioglitazone edema

A diabetic man on pioglitazone has leg edema with preserved EF.

What explains it?

  1. Decreased cardiac output from direct myocardial toxicity
  2. Increased hepatic production of angiotensinogen
  3. Increased sodium reabsorption in the renal collecting duct
  4. Venous insufficiency from direct endothelial damage
  5. Allergic interstitial nephritis with protein loss
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EndocrineBiochemistryEasyS1-EN-BTSC

Von Gierke disease

A 6-month-old has hepatomegaly, doll-like facies and irritability between feeds. Fasting glucose is 35, with lactate 8.2, uric acid 11.5 and triglycerides 680. Liver glycogen is increased but normal in structure, and glucagon raises lactate without raising glucose.

Which enzyme is deficient?

  1. Glycogen phosphorylase
  2. Acid α-glucosidase
  3. Debranching enzyme
  4. Phosphofructokinase
  5. Glucose-6-phosphatase
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Gastrointestinal & HepatobiliaryPathologyEasyS1-GI-BC5J

Familial adenomatous polyposis

Screening colonoscopy in a 45-year-old man finds twenty polyps scattered through the colon, all tubular adenomas on histology. His father died of colorectal cancer at 50.

Which gene is most likely mutated?

  1. MLH1
  2. PTEN
  3. STK11
  4. CDH1
  5. APC
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Gastrointestinal & HepatobiliaryPhysiologyMediumS1-GI-CCA6

Malnutrition in cirrhosis

A 46-year-old man with alcoholic cirrhosis has marked muscle wasting despite adequate calories. Albumin is 2.8; he is fatigued and has ascites and edema.

What contributes most to protein-energy malnutrition in cirrhosis?

  1. Decreased cytokine production
  2. Hypermetabolism with altered fuel utilization
  3. Decreased protein requirements
  4. Enhanced protein synthesis
  5. Improved branched-chain amino acid metabolism
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Gastrointestinal & HepatobiliaryBiochemistryEasyS1-GI-BK8Y

Von Gierke disease

A 3-month-old has poor growth, a big liver and fasting hypoglycemia with lactic acidosis. Liver biopsy shows massive glycogen in hepatocytes.

Which enzyme is most likely deficient?

  1. Pyruvate kinase
  2. Glycogen synthase
  3. Phosphofructokinase
  4. Glucose-6-phosphatase
  5. Alpha-glucosidase
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Gastrointestinal & HepatobiliaryPharmacologyEasyS1-GI-SNGA

Iron poisoning

Four hours after swallowing many iron tablets, a 3-year-old has severe belly pain, vomiting and bloody diarrhea.

What causes the GI injury?

  1. Decreased GI motility
  2. Allergic reaction to iron
  3. Bacterial overgrowth
  4. Osmotic diarrhea from unabsorbed iron
  5. Direct corrosive effect on GI mucosa
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Gastrointestinal & HepatobiliaryMicrobiologyEasyS1-GI-W9RY

Typhoid fever serology

A 25-year-old woman back from South Asia has a stepwise rising fever, relative bradycardia, rose spots and hepatosplenomegaly. Blood cultures grow non-lactose-fermenting gram-negative rods that produce H2S.

Which serologic test supports the diagnosis?

  1. Cold agglutinins
  2. Monospot test
  3. Widal test
  4. ASO titer
  5. Weil-Felix test
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Hematology & OncologyMicrobiologyEasyS1-HO-BNVC

EBV mononucleosis

A 30-year-old man has fever and pharyngitis with atypical lymphocytes and a positive Monospot test. A week later he has jaundice and lymphadenopathy, and a node biopsy shows large activated B cells with prominent nucleoli.

Which virus is most likely responsible?

  1. HIV
  2. Hepatitis C virus
  3. HTLV-1
  4. Human herpesvirus 8
  5. Epstein-Barr virus
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Hematology & OncologyPharmacologyEasyS1-HO-BJ6V

Low-dose aspirin GI balance

A woman with CAD on chronic aspirin 325 mg develops a bleeding gastric ulcer; aspirin is continued with a PPI at a reduced dose.

Which dose best balances cardiovascular benefit and GI safety?

  1. Aspirin 650 mg once daily to ensure complete thromboxane suppression through higher peak drug levels
  2. Aspirin 500 mg three times daily to achieve anti-inflammatory doses needed for optimal cardiovascular protection
  3. Aspirin 325 mg every other day to maintain equivalent platelet inhibition while halving mucosal exposure
  4. Aspirin 81 mg once daily providing full antiplatelet efficacy with reduced prostaglandin-mediated GI toxicity
  5. Aspirin 162 mg twice daily to achieve maximum COX-2 inhibition for anti-inflammatory cardiovascular benefit
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Hematology & OncologyPathologyMediumS1-HO-BRFH

Multiple myeloma marrow criterion

A 70-year-old man has bone pain and a pathologic femur fracture. X-rays show multiple lytic lesions in the skull and pelvis. Calcium is 12.5 mg/dL, creatinine 2.8 mg/dL, total protein 9.5 g/dL and albumin 3.5 g/dL. Serum electrophoresis shows an M-spike.

Which bone marrow finding would confirm the diagnosis?

  1. >40% plasma cells
  2. >10% plasma cells
  3. >50% plasma cells
  4. >30% plasma cells
  5. >20% plasma cells
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Hematology & OncologyBiochemistryEasyS1-HO-BNR9

Lead and heme synthesis

A 4-year-old in an old apartment has abdominal pain, constipation, behavior change, a gingival lead line, microcytic anemia, basophilic stippling and high protoporphyrin.

Which enzymes are inhibited?

  1. Cytochrome P450 oxidase
  2. Ferrochelatase and ALA dehydratase
  3. Glucose-6-phosphate dehydrogenase
  4. Carbonic anhydrase
  5. Pyruvate kinase
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Hematology & OncologyImmunologyEasyS1-HO-B2EZ

Acute GVHD

Three weeks after an HLA-matched sibling marrow transplant for SCID, a 7-year-old boy has a maculopapular rash, profuse diarrhea and bilirubin 6.8. Skin biopsy shows lymphocytes at the dermal-epidermal junction with dyskeratotic keratinocytes.

Which cells are responsible?

  1. Recipient NK cells
  2. Donor neutrophils
  3. Donor B lymphocytes
  4. Donor T lymphocytes
  5. Recipient T lymphocytes
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Multisystem & General PrinciplesPharmacologyEasyS1-MX-BA94

Vancomycin infusion reaction

Thirty minutes into a first vancomycin infusion, a man develops flushing of face and upper trunk, pruritus and mild hypotension, without airway symptoms; tryptase is normal.

What is the best next step?

  1. Permanently discontinue vancomycin and switch to linezolid
  2. Resume vancomycin at the same rate with close monitoring
  3. Administer intramuscular epinephrine immediately
  4. Slow the infusion rate and premedicate with diphenhydramine
  5. Obtain IgE-specific testing for vancomycin before re-challenge
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Multisystem & General PrinciplesMicrobiologyEasyS1-MX-E74R

Germ tube test

Blood cultures from a 29-year-old patient grow yeast. The lab needs to rapidly distinguish Candida albicans from other Candida species.

Which test is fastest?

  1. CHROMagar Candida
  2. Cornmeal agar morphology
  3. Germ tube test
  4. Urease test
  5. API 20C AUX
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Multisystem & General PrinciplesBiochemistryMediumS1-MX-KZBR

Mediator and Pol II CTD

Researchers map contacts in the preinitiation complex and find that Mediator, which links enhancer-bound transcription factors to the basal machinery, mainly contacts one region of RNA polymerase II.

Which domain of RNA polymerase II is Mediator's main partner?

  1. The trigger loop that controls nucleotide addition specificity
  2. The RNA exit channel where nascent transcript emerges
  3. The DNA entry cleft that guides template DNA into the active site
  4. The C-terminal domain (CTD) of the largest subunit (Rpb1)
  5. The active site catalytic center containing conserved metal ions
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Multisystem & General PrinciplesImmunologyMediumS1-MX-RWF2

TAP deficiency

A 28-year-old man has recurrent HSV infections with normal immunoglobulins and vaccine titers. CD8 T-cell and NK killing are impaired, and he has a homozygous loss-of-function TAP1 mutation.

Which process is primarily impaired?

  1. Cytokine receptor signaling
  2. MHC class II expression on APCs
  3. Peptide loading onto MHC class I
  4. T cell receptor gene rearrangement
  5. Immunoglobulin class switching
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Multisystem & General PrinciplesGeneticsEasyS1-MX-BYTX

Beckwith-Wiedemann imprinting

A 4.8-kg newborn (>97th percentile) has a large tongue, an omphalocele, overgrowth of the left leg and enlarged organs, and needs IV dextrose for hypoglycemia. At 3 months, ultrasound shows enlarged kidneys on both sides. Testing shows loss of maternal methylation at IC2 on 11p15.5, with IGF2 expressed from both alleles.

Which genetic mechanism explains his condition?

  1. Trinucleotide repeat expansion
  2. Genomic imprinting abnormality
  3. Mitochondrial mutation
  4. X-linked recessive inheritance
  5. Chromosomal translocation
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Musculoskeletal & SkinMicrobiologyMediumS1-MS-BR6X

Varicella risk

A pregnant woman had chickenpox at 8 weeks of pregnancy.

What is the approximate risk of congenital varicella syndrome?

  1. 50%
  2. 2%
  3. 10%
  4. <1%
  5. 25%
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Musculoskeletal & SkinPharmacologyEasyS1-MS-BVM9

Pseudocholinesterase

A healthy 32-year-old woman gets succinylcholine 1.5 mg/kg for rapid sequence intubation for appendectomy. Three hours later she is still paralyzed and ventilated, with 0/4 twitches on train-of-four. Her mother had a similar episode. Dibucaine number is 22 (normal >70).

Which enzyme is most likely deficient due to a genetic variant?

  1. Monoamine oxidase B in the central nervous system
  2. Hepatic N-acetyltransferase type 2
  3. Butyrylcholinesterase (pseudocholinesterase)
  4. Acetylcholinesterase at the neuromuscular junction
  5. Catechol-O-methyltransferase
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Musculoskeletal & SkinBiochemistryMediumS1-MS-K2CA

PRPP synthetase overactivity

A 45-year-old man has gout of the first MTP joint and recurrent uric acid stones. Serum urate is 12 mg/dL and 24-hour urinary uric acid is 1,200 mg/day. He has no neurologic findings and no family history.

Which enzymatic defect most likely explains the overproduction?

  1. Complete HGPRT deficiency causing total purine salvage pathway failure
  2. Decreased xanthine oxidase activity causing xanthine accumulation
  3. Glucose-6-phosphatase deficiency causing increased purine degradation from glycogen storage
  4. Increased phosphoribosyl pyrophosphate synthetase activity causing accelerated de novo purine synthesis
  5. Adenine phosphoribosyltransferase deficiency causing 2,8-dihydroxyadenine accumulation
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Musculoskeletal & SkinImmunologyEasyS1-MS-B2HC

Dermatomyositis mechanism

A 40-year-old woman has proximal weakness and a purple eyelid rash. Biopsy shows perifascicular atrophy and complement deposits on capillaries.

What mechanism explains the muscle injury?

  1. Direct T-cell cytotoxicity
  2. Complement-mediated microangiopathy
  3. Antibody-mediated muscle fiber damage
  4. Mitochondrial dysfunction
  5. Necrotizing autoantibody effects
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Musculoskeletal & SkinPathologyEasyS1-MS-B4EF

Mycosis fungoides

A 65-year-old man has scaly skin patches and plaques with lymphadenopathy. Skin biopsy shows atypical lymphocytes infiltrating the epidermis and clustering in Pautrier microabscesses. The cells are CD3+, CD4+ and CD7-.

What is the most likely diagnosis?

  1. Peripheral T-cell lymphoma, NOS
  2. Sézary syndrome
  3. Mycosis fungoides
  4. Adult T-cell leukemia/lymphoma
  5. Anaplastic large cell lymphoma
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Nervous SystemPathologyMediumS1-NR-BJZ5

Progranulin FTD

A 45-year-old man has progressive memory loss and behavior change. MRI shows atrophy of both anterior temporal lobes, his mother had similar symptoms, and genetic testing shows a progranulin mutation.

Which pathologic protein accumulates?

  1. TDP-43
  2. Beta-amyloid
  3. Prion protein
  4. Alpha-synuclein
  5. Tau
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Nervous SystemBiochemistryEasyS1-NR-BYWW

CVS

A couple has a child with spinal muscular atrophy type 1. Both parents are carriers. They want prenatal diagnosis next time.

Which test is most appropriate?

  1. Fetal ultrasound
  2. Maternal serum AFP
  3. Cordocentesis
  4. Non-invasive prenatal testing
  5. Chorionic villus sampling
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Nervous SystemPhysiologyMediumS1-NR-BQFH

Blocked sodium inactivation

A 30-year-old woman exposed to a toxin that blocks fast sodium channel inactivation has paralysis and prolonged contractions.

What is the most likely effect on the action potential?

  1. Shortened refractory period
  2. Prolonged depolarization
  3. Reduced action potential amplitude
  4. Failure of action potential initiation
  5. Increased conduction velocity
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Nervous SystemAnatomyEasyS1-NR-2FV9

Anterior communicating aneurysm

A 52-year-old woman has a sudden severe headache, stiff neck and photophobia. CSF is xanthochromic, and CT angiography shows an anterior communicating artery aneurysm.

Which structures are most at risk from its rupture?

  1. Hypothalamus and optic chiasm
  2. Hippocampus and fornix
  3. Internal capsule
  4. Caudate nucleus
  5. Corpus callosum only
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Nervous SystemPharmacologyMediumS1-NR-BXWG

MS disease-modifying therapy

A 30-year-old woman with optic neuritis has periventricular MRI lesions and CSF oligoclonal bands. She improves on steroids but relapses 6 months later.

Which medication most effectively prevents relapses?

  1. Interferon beta
  2. Plasma exchange
  3. Cyclophosphamide
  4. IVIg
  5. Chronic corticosteroids
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Renal & UrinaryMicrobiologyEasyS1-RN-NBUN

Staphylococcus saprophyticus

A 25-year-old woman has 2 days of dysuria and frequency without fever or flank pain. Urine grows catalase-positive, coagulase-negative gram-positive cocci that are novobiocin resistant.

What is the most likely organism?

  1. Streptococcus pyogenes
  2. Staphylococcus epidermidis
  3. Enterococcus faecalis
  4. Staphylococcus aureus
  5. Staphylococcus saprophyticus
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Renal & UrinaryPharmacologyMediumS1-RN-AZZS

Anti-GBM disease treatment

A 40-year-old man has 3 weeks of hemoptysis and dyspnea, plus dark urine and oliguria. BUN 65, creatinine 5.2, RBC casts. Chest film shows bilateral alveolar infiltrates. Anti-GBM antibody is high, and biopsy shows crescents with linear IgG along the GBM. Plasmapheresis is started.

Which part of treatment prevents antibody rebound?

  1. Rituximab
  2. Cyclophosphamide
  3. Mycophenolate
  4. Azathioprine
  5. Prednisone
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Renal & UrinaryPathologyEasyS1-RN-BJHD

Wilms BWS

A 6-month-old infant has an abdominal mass and high blood pressure. CT shows a large kidney mass with a claw sign. Histology shows blastemal, epithelial and stromal parts.

Which genetic syndrome has the strongest link among the choices?

  1. Tuberous sclerosis
  2. Beckwith-Wiedemann syndrome
  3. Neurofibromatosis type 1
  4. Von Hippel-Lindau syndrome
  5. Li-Fraumeni syndrome
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Renal & UrinaryPhysiologyMediumS1-RN-3Q6W

Distal RTA

A 40-year-old woman has had bilateral calcium phosphate stones for 5 years, with weakness and bone pain. K+ is 2.9 mEq/L, Cl- 112 mEq/L, HCO3- 16 mEq/L, with a normal anion gap acidosis. Urine pH is always above 7.0, urine calcium is high and citrate low. After ammonium chloride loading, urine pH does not fall below 5.5.

Which diagnosis best explains these findings?

  1. Distal renal tubular acidosis with impaired hydrogen ion secretion
  2. Chronic carbonic anhydrase inhibitor use causing proximal bicarbonate wasting
  3. Milk-alkali syndrome with compensatory renal acid retention
  4. Urease-producing bacterial infection causing alkaline urine
  5. Primary hyperparathyroidism with increased renal calcium excretion
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Renal & UrinaryImmunologyMediumS1-RN-BPRN

BK virus after transplant

On day 45 after an allogeneic marrow transplant for AML, a 55-year-old man has visible blood in his urine, painful urination and suprapubic pain. Urine culture is negative and urine PCR shows a high BK polyomavirus load.

Loss of which immune component mainly allows this virus to reactivate?

  1. Loss of complement-mediated virolysis through the classical pathway activated by anti-viral IgM antibodies
  2. Loss of virus-specific CD8+ cytotoxic T lymphocytes that recognize viral peptides presented on MHC class I molecules
  3. Loss of neutrophil-mediated oxidative burst that generates reactive oxygen species to kill intracellular pathogens
  4. Loss of interferon-gamma-producing CD4+ Th1 helper T cells that activate macrophage-mediated viral clearance
  5. Loss of natural killer (NK) cell surveillance that normally recognizes and destroys virus-infected cells lacking MHC class I
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ReproductiveGeneticsEasyS1-RP-VRXZ

Limits of cell-free DNA testing

At 12 weeks, a 32-year-old woman's cell-free DNA test shows high risk for trisomy 21. She asks if this confirms Down syndrome.

Which statement about this screening test is correct?

  1. It cannot determine fetal sex
  2. Requires amniocentesis confirmation of positive results
  3. It can be performed only after 20 weeks gestation
  4. It has a 50% false positive rate
  5. It only detects trisomy 21 and no other aneuploidies
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ReproductiveBiochemistryMediumS1-RP-BZ4R

Balanced translocation miscarriage

A 28-year-old woman has had several pregnancy losses. Karyotype shows a balanced translocation.

Which meiotic event explains the losses?

  1. Sister chromatid separation
  2. Crossing over
  3. Polar body extrusion
  4. Nondisjunction
  5. Unbalanced segregation
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ReproductivePharmacologyEasyS1-RP-BY6Y

Trichomonas treatment

A 35-year-old woman has had frothy green vaginal discharge and itching for 3 days, with mild dysuria. Her cervix is red with punctate hemorrhages, and a wet mount shows motile flagellated protozoa. She recently took antibiotics for a UTI and has one sexual partner.

What is the treatment of choice?

  1. Metronidazole
  2. Acyclovir
  3. Doxycycline
  4. Fluconazole
  5. Azithromycin
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ReproductivePathologyMediumS1-RP-BXR9

Mediastinal chorio

A 28-year-old man has an anterior mediastinal mass and breast growth. Beta-hCG is high and AFP is normal. Biopsy shows bloody tissue with cytotrophoblasts and syncytiotrophoblasts.

What is the diagnosis?

  1. Choriocarcinoma
  2. Mature teratoma
  3. Seminoma
  4. Yolk sac tumor
  5. Embryonal carcinoma
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ReproductiveMicrobiologyEasyS1-RP-6DKU

Mumps orchitis

An incompletely vaccinated 8-year-old boy has fever and swollen parotid glands after contact with a classmate with the same illness.

Which complication is most common in males past puberty?

  1. Pancreatitis
  2. Orchitis
  3. Deafness
  4. Meningitis
  5. Myocarditis
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RespiratoryMicrobiologyEasyS1-RS-H7SU

Klebsiella pneumonia

A 40-year-old man with heavy alcohol use has fever, pleuritic pain and thick, bloody 'currant jelly' sputum. X-ray shows dense right upper lobe consolidation with a bulging fissure. Gram stain shows plump gram-negative rods with a large mucoid capsule.

What best explains the large amount of exudate?

  1. Biofilm formation in the airways traps inflammatory cells and fluid
  2. A thick mucoid polysaccharide capsule causes copious exudate and resists phagocytosis
  3. Hemolysins destroy pulmonary capillary endothelium leading to hemorrhagic exudate
  4. Lipopolysaccharide activates massive toll-like receptor 4 inflammatory cascade
  5. The organism produces an exotoxin that directly increases vascular permeability
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RespiratoryPharmacologyMediumS1-RS-B462

Inpatient CAP regimen

A woman with severe COPD is admitted with fever, purulent sputum and a lobar infiltrate, SpO2 89 percent. She once had angioedema to TMP-SMX. She has no MRSA or Pseudomonas risk factors.

Which empiric regimen is most appropriate?

  1. Levofloxacin monotherapy
  2. Doxycycline plus metronidazole
  3. Azithromycin monotherapy
  4. Piperacillin-tazobactam plus vancomycin
  5. Ceftriaxone plus azithromycin
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RespiratoryImmunologyEasyS1-RS-KC7T

Bronchiolitis obliterans in chronic GVHD

Eighteen months after an allogeneic marrow transplant, a 38-year-old woman has worsening breathlessness and dry cough. FEV1 has fallen from 95% to 40% with fixed obstruction. HRCT shows air trapping, and biopsy shows small airways blocked by concentric fibrosis. She is diagnosed with bronchiolitis obliterans from chronic GVHD.

Which immune process drives this airway destruction?

  1. Complement-mediated damage
  2. NK cell cytotoxicity
  3. Eosinophilic inflammation
  4. Recipient B cells producing autoantibodies
  5. Donor T cells causing fibrosis
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RespiratoryPathologyMediumS1-RS-BHGZ

Bird fanciers lung

A 50-year-old woman who breeds birds has chronic dyspnea and cough with upper-lobe ground glass and fibrosis.

Which finding is most likely?

  1. Lymphocytic infiltration with germinal centers
  2. Eosinophilic infiltration with Charcot-Leyden crystals
  3. Chronic granulomatous inflammation with giant cells
  4. Neutrophilic infiltration with abscess formation
  5. Plasma cell infiltration with Russell bodies
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RespiratoryBiochemistryMediumS1-RS-BHQ4

Benzo[a]pyrene TP53

A 65-year-old man with 40 pack-years develops lung cancer. Tumor sequencing shows G→T transversions in TP53.

Which carcinogen metabolite most likely caused this?

  1. Vinyl chloride
  2. Aflatoxin B1
  3. Aromatic amines
  4. N-nitrosamine
  5. Benzo[a]pyrene diol epoxide
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