A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 31 year-old African-American female presents with a painful shin nodules, uveitis, and calcified hilar lymph nodes. A transbronchial biopsy of the lung would most likely show which of the following histologies?
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A
Silica particles (birefringent) surrounded by collagenIncorrect. Silicosis (silica particles with collagen) would be seen in occupationally exposed patients (miners, sandblasters), with eggshell calcification of hilar nodes — but presents differently with progressive dyspnea and isn't associated with erythema nodosum and uveitis in this demographic.
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B
Golden-brown fusiform rodsIncorrect. Golden-brown fusiform rods describe ASBESTOS (ferruginous) bodies — seen in asbestos-related lung disease, which causes pleural plaques and mesothelioma. Not the picture here.
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C
Patchy interstitial lymphoid infiltrate into walls of alveolar unitsIncorrect. Patchy interstitial lymphoid infiltrate describes hypersensitivity pneumonitis or interstitial pneumonia — not the granulomatous, sarcoidosis picture.
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D
Non-caseating granulomasCorrect. Non-caseating granulomas are the histologic hallmark of sarcoidosis. The clinical picture (African-American woman with Löfgren syndrome: erythema nodosum + bilateral hilar adenopathy + uveitis) is classic.
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E
Caseating granulomas with acid-fast bacilliIncorrect. Caseating granulomas with AFB describe pulmonary tuberculosis, which can also cause hilar adenopathy but presents with constitutional symptoms (fever, night sweats, weight loss) and rarely uveitis with erythema nodosum; sarcoidosis shows NON-caseating granulomas.
↑ Tap an answer to reveal the reasoning
Answer: D. A young African-American woman with painful shin nodules (ERYTHEMA NODOSUM), uveitis, and bilateral hilar lymphadenopathy with calcification has SARCOIDOSIS. Transbronchial biopsy of the lung would show NON-CASEATING GRANULOMAS, the histologic hallmark.
Sarcoidosis is a multisystem granulomatous disorder of unknown etiology with a striking demographic predilection for African-American women aged 20–40. Pulmonary involvement (≥90% of cases) produces bilateral hilar lymphadenopathy and parenchymal infiltrates. Other features include:
- LÖFGREN SYNDROME: erythema nodosum + bilateral hilar adenopathy + arthralgia + fever (this patient's presentation)
- Uveitis (anterior or posterior)
- Skin: lupus pernio, plaques, papules
- Cardiac: conduction defects, cardiomyopathy
- CNS: cranial nerve palsies (especially CN VII), neuroendocrine dysfunction
- HYPERCALCEMIA from 1α-hydroxylase activity in granulomas converting 25-OH-D to 1,25-(OH)2-D
- Elevated ACE (in ~60% of patients)
The pathology shows NON-CASEATING granulomas — well-formed collections of epithelioid macrophages and multinucleated giant cells WITHOUT central necrosis. Compare to TB (CASEATING granulomas, AFB-positive). Asteroid bodies and Schaumann bodies may be seen within giant cells.
Treatment: many cases resolve spontaneously; symptomatic disease is treated with corticosteroids, with methotrexate or biologics for refractory cases.
**Why each option:**
**A.** Silicosis (silica particles with collagen) would be seen in occupationally exposed patients (miners, sandblasters), with eggshell calcification of hilar nodes — but presents differently with progressive dyspnea and isn't associated with erythema nodosum and uveitis in this demographic.
**B.** Golden-brown fusiform rods describe ASBESTOS (ferruginous) bodies — seen in asbestos-related lung disease, which causes pleural plaques and mesothelioma. Not the picture here.
**C.** Patchy interstitial lymphoid infiltrate describes hypersensitivity pneumonitis or interstitial pneumonia — not the granulomatous, sarcoidosis picture.
**D.** Correct. Non-caseating granulomas are the histologic hallmark of sarcoidosis. The clinical picture (African-American woman with Löfgren syndrome: erythema nodosum + bilateral hilar adenopathy + uveitis) is classic.