Atypical radiographic features in Pneumocystis carinii pneumonia.

The chest films in 30 proved cases of Pneumocystis carinii pneumonia were reviewed to determine the incidence of atypical radiographic findings. Seventeen of 30 patients or 56% presented at least one atypical radiographic finding during the course of the disease. Unilateral distribution, lobar involvement, abscess formation, fulminant progression, and atelectatic changes were observed in more than half the patients. A classic radiographic presentation, justifying treatment without biopsy, was seen in only 13 of the 30 patients.