Mixed Deck — All ABIM Topics Flashcards

A 59-year-old man presents with progressive symmetric distal lower extremity weakness, hyporeflexia, and a stocking-glove pattern of sensory loss. He was treated for lymphoma 6 months ago. Nerve conduction studies show axonal sensorimotor neuropathy. What is the most likely cause?

Answer: Vincristine-induced neuropathy

Vincristine causes a length-dependent axonal sensorimotor polyneuropathy that typically manifests during or after chemotherapy for lymphoma.

A 66-year-old man with atrial fibrillation and CHA₂DS₂-VASc score of 4 is on warfarin (INR 2.4). He develops hematuria and hemoglobin drops from 13 to 10 g/dL. What is the most appropriate management of anticoagulation?

Answer: Hold warfarin and reverse with vitamin K; resume after source identified and treated

Significant bleeding warrants holding anticoagulation and identifying the source; warfarin should be resumed once hemostasis is achieved given his high stroke risk.

A 62-year-old smoker presents with a 3.5 cm spiculated lung nodule on CT. PET scan shows hypermetabolic activity. What is the next step?

Answer: CT-guided biopsy or surgical resection

A spiculated >3 cm pulmonary nodule with PET hypermetabolic activity in a smoker is highly suspicious for malignancy and requires tissue diagnosis via biopsy or surgical resection.

A 45-year-old man with chronic hepatitis C (genotype 1a) is started on direct-acting antiviral therapy. Twelve weeks after completing treatment, HCV RNA is undetectable. What does this represent?

Answer: Sustained virological response (SVR) — considered cured

Sustained virological response (SVR) is defined as undetectable HCV RNA 12 weeks after completing therapy and is considered a cure with >99% durability.

What is the preferred treatment for a hemodynamically stable patient with new-onset atrial flutter with a ventricular rate of 140 bpm?

Answer: Rate control with IV diltiazem

For hemodynamically stable atrial flutter with rapid ventricular response, IV diltiazem or beta-blockers provide rapid rate control while anticoagulation and rhythm control are planned.

A 35-year-old woman presents with recurrent episodes of severe abdominal pain, vomiting, and port-wine colored urine precipitated by fasting and oral contraceptive use. Urine porphobilinogen is markedly elevated during attacks. What is the most appropriate acute treatment?

Answer: IV hemin (heme arginate) and glucose loading

Acute attacks of acute intermittent porphyria are treated with IV hemin, which represses ALA synthase, and high glucose loading to suppress the heme biosynthesis pathway.

A 55-year-old man with known alcoholic cirrhosis (Child-Pugh B) presents with acute onset abdominal pain and fever. Diagnostic paracentesis shows PMN count of 350 cells/µL. What is the most appropriate treatment?

Answer: IV cefotaxime (or ceftriaxone) plus IV albumin

Spontaneous bacterial peritonitis (PMN ≥250/µL) is treated with IV third-generation cephalosporin plus albumin infusion (1.5 g/kg at diagnosis, 1 g/kg on day 3) to prevent hepatorenal syndrome.

An occasional burning sensation in the lower extremities has been prevalent in the patient for the past 50 years. The patient routinely exercises and follows a strict vegan diet. The previous medical history is not noteworthy. The physical examination went as expected. The results of pertinent tests are displayed below. Which of the following best represents the evaluation's next phase?

Answer: Serum methylmalonic acid and homocysteine levels

Clinical signs of vitamin B12 insufficiency in this patient include macrocytic anemia, neurological symptoms, a strict vegan diet, and borderline blood B12 levels. Methylmalonic acid and homocysteine levels can be checked in this situation to confirm the diagnosis. Due to their buildup in the setting of vitamin B12 insufficiency, both intermediates will grow. (In folate insufficiency, just homocysteine will be raised). The next step would be to look for the cause of a vitamin B12 insufficiency diagnosis to be made and confirmed. The patient's strict vegan diet is the most likely cause in this case. Even while electromyography and nerve conduction testing would show that neuropathy existed, they would not give the required details to identify the cause. Similarly, if other causes are ruled out, a computed tomography (CT) of the lumbosacral spine can be necessary. However, there are better courses of action than this when enough clinical data points to a vitamin shortage. The best way to define the patient's folate and vitamin B12 levels is borderline. Therefore, there are better courses of action than administering a therapeutic dose of vitamin B12 without first determining what is causing the neurological symptoms. A bone marrow analysis would not be required now because the peripheral blood smear and complete blood count showed no further related cellular abnormalities. The cause is more likely to be discovered by less invasive tests (such as serum metabolite intermediates).

A 60-year-old man with type 2 diabetes has HbA1c of 8.9% on metformin monotherapy. He has CKD stage 3a (GFR 48 mL/min) and no cardiovascular disease. What is the best add-on therapy?

Answer: GLP-1 receptor agonist

GLP-1 receptor agonists have cardiovascular and renal benefits, are effective at all GFR levels (most agents), and reduce HbA1c significantly, making them preferred add-on therapy.

A patient presents with fever, flank pain, and dysuria. Blood cultures grow E. coli. CT scan shows a gas-forming infection within the renal parenchyma. What is the diagnosis?

Answer: Emphysematous pyelonephritis

Emphysematous pyelonephritis is a life-threatening necrotizing infection of the renal parenchyma with gas formation, occurring predominantly in diabetic patients.

A 55-year-old man with known cirrhosis develops confusion, asterixis, and jaundice. His INR is 2.1, bilirubin 8.4 mg/dL, and creatinine 2.8 mg/dL. By which scoring system is he best stratified for transplant priority?

Answer: MELD-Na score

MELD-Na (Model for End-stage Liver Disease with sodium) is the standard scoring system used by UNOS to prioritize liver transplant candidates.

Which statement about DDAVP (desmopressin) is accurate?

Answer: It should not be given chronically to prevent bleeding in patients with moderate von Willebrand disease (vWD).

DDAVP, a vasopressin analog, can increase the ADH axis's activity and result in hyponatremia. Additionally, it has been demonstrated to promote endothelial cell release of von Willebrand factor. However, this medication might cause tachyphylaxis, and its effectiveness usually wears off after two or three consecutive doses. As a result, it cannot be administered again. When von Willebrand factor attaches to glycoprotein 1, related to type IIB vWD, more platelets are cleared from the body. In individuals with type IIB vWD, DDAVP, which increases the release of von Willebrand factor, can result in thrombosis and severe thrombocytopenia and shouldn't be administered in this situation.

A 25-year-old man presents with low back pain and morning stiffness that improves with exercise, positive HLA-B27, and sacroiliitis on imaging. What is the most appropriate initial treatment?

Answer: NSAIDs

NSAIDs are the first-line treatment for ankylosing spondylitis (axial spondyloarthropathy); TNF inhibitors or IL-17 inhibitors are added if NSAIDs provide insufficient relief.

A patient presents with oliguria after surgery. BUN is 42 mg/dL, creatinine is 1.4 mg/dL (BUN:Cr ratio = 30). Urine sodium is 8 mEq/L and FENa is 0.5%. What is the most likely diagnosis?

Answer: Prerenal azotemia

Prerenal azotemia is characterized by elevated BUN:Cr ratio (>20), low urine sodium (<20 mEq/L), and FENa <1%, reflecting intact tubular function with avid sodium reabsorption.

A 45-year-old woman is found to have a serum calcium of 11.2 mg/dL on routine labs. PTH is elevated at 92 pg/mL. She is asymptomatic with a creatinine of 1.0 mg/dL and a DEXA T-score of -1.8. What is the most appropriate management?

Answer: Observation with annual monitoring

Asymptomatic primary hyperparathyroidism without meeting surgical criteria (T-score ≤ -2.5, age 1 mg/dL above normal, creatinine clearance <60) is managed with observation.

A 50-year-old man with Barrett esophagus (non-dysplastic, confirmed on two endoscopies) asks about surveillance. What is the recommended surveillance interval?

Answer: Every 3–5 years

Non-dysplastic Barrett esophagus has a low malignant potential (~0.3% per year), and current guidelines recommend surveillance endoscopy every 3–5 years.

A patient with CKD stage 3b has a hemoglobin of 9.5 g/dL with low reticulocyte count and low iron stores. What is the correct sequence of treatment?

Answer: Replete iron first, then reassess for ESA therapy

Iron deficiency must be corrected before initiating ESA therapy in CKD-related anemia, as functional iron deficiency blunts ESA response.

A 62-year-old man is found to have a 3-cm solid pulmonary nodule on CT. PET scan shows no FDG uptake. Bronchoscopy is non-diagnostic. What is the most appropriate next step according to evidence-based guidelines?

Answer: Video-assisted thoracoscopic surgery (VATS) resection

A solid nodule ≥3 cm with a non-diagnostic bronchoscopy warrants surgical resection (VATS) because malignancy risk is high regardless of PET negativity.

A 53-year-old man presents with confusion and asterixis. His wife notes he has been drinking heavily for 20 years. Labs reveal ammonia 142 µmol/L, total bilirubin 4.2 mg/dL, and INR 2.1. What precipitating factor should be investigated first in hepatic encephalopathy?

Answer: Gastrointestinal bleeding

GI bleeding is the most common precipitant of hepatic encephalopathy in cirrhotics, as blood in the gut is a large nitrogenous load that dramatically raises ammonia.

A 40-year-old man has an incidentally found 2.5 cm adrenal mass. It appears lipid-rich on CT (HU < 10). He is normotensive with normal electrolytes. What should be done?

Answer: Biochemical evaluation for hormonal hypersecretion

All adrenal incidentalomas require biochemical evaluation for pheochromocytoma, subclinical Cushing syndrome, and primary aldosteronism, regardless of imaging characteristics.