Inflammation and Immune Pathology USMLE Step 1 Practice Question
A 55-year-old male with a 30 pack-year smoking history presents with a 3-month history of progressive dyspnea and dry cough. He denies fever, night sweats, or weight loss. Vital signs: HR 92/min, RR 22/min, BP 138/86, SpO2 88% on room air, Temperature 37.2°C. Physical examination reveals bilateral hilar lymphadenopathy on chest X-ray. Laboratory studies show serum calcium 11.8 mg/dL (normal 8.5-10.5), ACE level elevated at 68 U/L (normal <30), and normal 24-hour urine calcium. Tuberculin skin test is negative. Lung biopsy demonstrates noncaseating granulomas with multinucleated giant cells. Which of the following best explains this clinical presentation?
Answer choices
- ATuberculosisâcaseating granulomas with acid-fast bacilli would be present on histology
- BHistoplasmosisâfungal elements would be visible on biopsy and caseating granulomas are typical
- CHypersensitivity pneumonitisâwould show lymphocytic infiltration with poorly formed granulomas and requires antigen exposure history
- DChronic beryllium diseaseânoncaseating granulomas present but requires beryllium exposure history and abnormal beryllium lymphocyte proliferation test
- ESarcoidosisânoncaseating granulomas, negative TST, elevated serum ACE, and hypercalcemia are classic findingsCorrect answer
- FAspergillosisâwould show fungal elements on histology and typically cavitary lung lesions rather than hilar lymphadenopathy
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