SPEX Internal Medicine 3 — Questions and Answers
Question 1: A 48-year-old woman presents with episodic hypertension, headache, palpitations, and diaphoresis. Plasma metanephrines are markedly elevated. What is the definitive treatment?
- Lifelong alpha-blockade with phenoxybenzamine
- Surgical resection of the tumor after alpha-blockade (Correct answer)
- Beta-blockade followed by surgery
- Bilateral adrenalectomy without preoperative preparation
Correct answer: Surgical resection of the tumor after alpha-blockade
Pheochromocytoma requires alpha-blockade (e.g., phenoxybenzamine) for 1–2 weeks before surgical resection to prevent hypertensive crisis intraoperatively.
Question 2: A 30-year-old man with HIV (CD4 count 80 cells/µL) presents with a ring-enhancing brain lesion on MRI and positive Toxoplasma IgG serology. What is the most appropriate initial management?
- Immediate stereotactic brain biopsy
- Empiric pyrimethamine + sulfadiazine + leucovorin (Correct answer)
- IV amphotericin B
- High-dose corticosteroids alone
Correct answer: Empiric pyrimethamine + sulfadiazine + leucovorin
In HIV patients with CD4 <100 and positive Toxoplasma serology, empiric anti-toxoplasma therapy is initiated; response within 2 weeks confirms the diagnosis.
Question 3: A 72-year-old man with heart failure (EF 30%) is started on carvedilol. Which mechanism best explains the benefit of beta-blockers in heart failure with reduced ejection fraction?
- Increased cardiac contractility through positive inotropy
- Reversal of maladaptive cardiac remodeling by blocking sympathetic activation (Correct answer)
- Reduction of preload via venodilation
- Blockade of aldosterone receptors in the kidney
Correct answer: Reversal of maladaptive cardiac remodeling by blocking sympathetic activation
Chronic sympathetic activation in HFrEF causes maladaptive remodeling; beta-blockers reverse this by reducing heart rate and myocardial oxygen demand.
Question 4: A 40-year-old woman presents with amenorrhea, galactorrhea, and visual field defects. MRI shows a 1.8 cm sellar mass. What is the first-line treatment?
- Transsphenoidal surgery
- Bromocriptine or cabergoline (dopamine agonist) (Correct answer)
- Radiation therapy
- High-dose corticosteroids
Correct answer: Bromocriptine or cabergoline (dopamine agonist)
Macroprolactinomas are first-line treated with dopamine agonists (cabergoline preferred), which shrink the tumor and normalize prolactin levels.
Question 5: A patient with chronic liver disease develops worsening confusion, asterixis, and elevated ammonia despite lactulose therapy. Which additional intervention is most evidence-based for reducing hepatic encephalopathy recurrence?
- Neomycin long-term therapy
- Rifaximin 550 mg twice daily (Correct answer)
- Protein restriction to <20 g/day
- Zinc supplementation alone
Correct answer: Rifaximin 550 mg twice daily
Rifaximin, a minimally absorbed antibiotic, reduces intestinal ammonia-producing bacteria and is proven to prevent recurrence of hepatic encephalopathy.
Question 6: A 65-year-old woman with rheumatoid arthritis on methotrexate 15 mg/week presents with macrocytic anemia, oral ulcers, and elevated LFTs. What is the most appropriate intervention?
- Discontinue methotrexate permanently
- Add folic acid 1 mg daily (Correct answer)
- Switch to hydroxychloroquine
- Increase methotrexate dose
Correct answer: Add folic acid 1 mg daily
Folic acid supplementation (1 mg/day) reduces methotrexate toxicity including mucositis, hepatotoxicity, and cytopenias without diminishing its anti-inflammatory efficacy.
Question 7: A 55-year-old man with a long smoking history presents with hyponatremia (Na 122 mEq/L), concentrated urine, and a pulmonary mass on chest X-ray. What is the underlying mechanism of his hyponatremia?
- Cerebral salt wasting
- Syndrome of inappropriate ADH secretion (SIADH) (Correct answer)
- Adrenal insufficiency
- Hypothyroidism-induced hyponatremia
Correct answer: Syndrome of inappropriate ADH secretion (SIADH)
Small cell lung carcinoma is the most common malignancy associated with SIADH, which causes euvolemic hyponatremia with concentrated urine.
SPEX Internal Medicine 3
A 48-year-old woman presents with episodic hypertension, headache, palpitations, and diaphoresis.
Plasma metanephrines are markedly elevated.
What is the definitive treatment?