AIDS-related Pneumocystis carinii pneumonia with disappearance of cystic lesions after treatment.

A 21-year-old hemophiliac with human immunodeficiency virus (HIV) infection was admitted to our hospital because of bilateral pneumothoraces associated with Pneumocysis carinii pneumonia (PCP). He underwent chest tube drainages and intravenous pentamidine therapy, resulting in clinical improvement. Two months after treatment for PCP, cystic lesions that had existed before treatment disappeared on chest computed tomography. We concluded that Pneumocystis carinii infection might be associated with lung destruction and cyst formation, and that inflammatory exudates in the small bronchioles might act as a ball-valve with subsequent spontaneous pneumothoraces.