Isolation of Allescheria boydii from pleural fluid.

Allescheria boydii was repeatedly isolated from thoracentesis fluid from a patient with a right pleural effusion. Histological study of methanamine-stained pleural tissue revealed the presence of septate hyphae. After a thoracotomy and decortication, the patient's symptoms cleared, and he has remained asymptomatic over a postoperative period of 13 months.