We describe a case of microscopic polyangiitis manifested as pleuritis confirmed by thoracoscopic biopsy. An 80-year-old man presented with a three-day history of shortness of breath and cough. Chest radiography revealed patchy opacities in the lower fields of the bilateral lung and right-sided pleural effusion. Thoracentesis revealed lymphocytic pleural exudates. Thoracoscopic biopsy specimens were compatible with fibrotic pleuritis. He developed rapidly progressive glomerulonephritis with elevated myeloperoxidase anti-neutrophil cytoplasmic antibody titer in blood and pleural effusion. Although the patient was resistant to two weekly courses of pulse steroid therapy, he was successfully treated with a five-day course of intravenous immunoglobulin.
Keywords: Microscopic polyangiitis; pleuritis; thoracoscopy..