Caplan lesion

Caplan syndrome

A condition defined by the combination of rheumatoid arthritis and pneumoconiosis linked to mining dusts—e.g., asbestos, coal, silicates.

Clinical findings
Swollen joints, rheumatoid nodules, cough and dyspnoea.

Caplan lesion

Caplan syndrome, rheumatoid pneumoconiosis Pulmonary medicine A large > 4 cm in diameter silicotic nodule, with smooth borders, peripheral palisading of macrophages, concentric internal lamination, and central necrosis; CLs may represent juxtaposition of silicotic and rheumatoid nodules. See Rheumatoid arthritis, Silicosis.