Caplan syndrome is a specific entity seen in coal miners with rheumatoid arthritis. The radiological finding that distinguishes Caplan syndrome from simple progressive massive fibrosis in coal workers is:
- A Bilateral lower-lobe interstitial fibrosis
- B Multiple well-defined rounded nodules (0.5–5 cm) appearing rapidly, often in crops, peripherally ✓
- C Eggshell calcification of hilar nodes
- D Honeycombing pattern with sub-pleural cysts
Correct answer: B. Multiple well-defined rounded nodules (0.5–5 cm) appearing rapidly, often in crops, peripherally
Explanation
Caplan syndrome (rheumatoid pneumoconiosis) refers to the rapid appearance of multiple, well-defined large rounded nodules (usually 0.5–5 cm, sometimes up to 7 cm) throughout the lung parenchyma in coal workers who have rheumatoid arthritis. These nodules appear in crops, may cavitate, and are distributed peripherally/sub-pleurally — quite distinct from the slow, progressive massive fibrosis of simple pneumoconiosis. Eggshell calcification is seen in silicosis, not coal-workers' pneumoconiosis. Honeycombing is a UIP pattern seen in IPF.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.