Pneumocystis carinii pneumonitis in patients with lung cancer.

Pneumocystis carinii pneumonia was histologically documented in five patients with bronchogenic carcinoma. All patients had been treated with combination antineoplastic chemotherapy. Two patients received no corticosteroids, two received no chest radiotherapy, and one received neither radiotherapy nor corticosteroids. This suggests that as more patients with lung cancer are treated with intensive chemotherapy, pulmonary infection with P carinii may become an important differential diagnostic consideration in the presence of pulmonary infiltrates.