[Recurrence of atypical pulmonary pneumocystosis treated with pentamidine aerosol]

Two cases are reported of atypical relapses of pneumocystosis in AIDS patients treated with aerosol pentamidine for 14 and 22 months. These pneumopathies are unusual because of their pitted aspect and recurrent spontaneous pneumothoraxes in spite of repeated drainage. They are difficult to diagnose because bronchoalveolar lavage fluid is negative for Pneumocystis carinii, despite their presence in lung biopsies. Histological lesions vary, being granulomatous, necrotizing and invasive, with involvement of the pleura and lymph nodes. Although a highly effective therapy against P. carinii pneumonia, aerosol pentamidine may play a role in these atypical episodes: either by causing bronchial obstructions beyond which the pneumocytotic lesions cannot be reached by lavage and become necrotic, or by favoring the extrapulmonary spread of P. carinii.