Diagnosis of Pneumocystis carinii pneumonia by cytologic examination of bronchial washings.

During the last three years, bronchial washings from patients in whom Pneumocystis carinii pneumonia was clinically suspected were cytologically examined. These were predominantly cases of suspected or confirmed acquired immunodeficiency syndrome. To determine the effectiveness of cytologic diagnosis by means of a bronchial wash, retrospective analysis of bronchial washings with available simultaneous transbronchial biopsy specimens was carried out in 181 cases. Comparison of the results of both methods revealed an excellent correlation. Pneumocystis carinii was identified in 108 specimens of washes and in 103 specimens of biopsies. Our data indicate that P carinii can be consistently and reliably identified in the smears from bronchial washes, without lung tissue biopsy, thus sparing the patient the latter procedure if contraindications exist.