Caplan syndrome in the 21st century: Cavitary nodules and delayed rheumatoid arthritis.

Caplan syndrome, a rare condition characterized by the coexistence of pneumoconiosis and rheumatoid arthritis in individuals exposed to inorganic dust, remains a relevant diagnostic consideration in the 21st century. We present a case of a 41-year-old former coal miner who developed multiple cavitary pulmonary nodules years after leaving the mining sector, initially mimicking pulmonary malignancy. Extensive diagnostic work-up, including positron emission tomography-computed tomography, bronchoscopy and lung biopsy, eventually led to the diagnosis of Caplan syndrome, with seropositive rheumatoid arthritis emerging 8 years after exposure cessation. This case highlights the delayed autoimmune effects of occupational inhalants and underscores the ongoing need for vigilance and improved occupational health measures in high-risk industries.