Pleural vasculitides

A 69‐year‐old man who had been exposed to asbestos for approximately 40 years presented with the complaint of fever and pleuritic chest pain on the right side on deep inspiration. Chest X‐ray films showed pleural effusion in the right side. Initial antibiotic treatment was ineffective. The hyaluronic acid level was high in the pleural effusion but no malignant mesotheliomal cells were seen with blind pleural biopsy. Blood chemistry showed a remarkable high titer of myeloperoxidase anti‐neutrophil cytoplasmic antibody (MPO‐ANCA) and open renal biopsy suggested crescentic glomerulonephritis. The precise pathological examination on the pleura obtained by the open pleural biopsy showed vasculitides and plaque leading to diagnosis of microscopic polyangiitis (MPA). This is a rare case of MPA seen in the pleural arteries.