ABSTRACT
Development of diffuse pulmonary infiltrates in patients receiving chemotherapy is a major diagnostic challenge. Diffuse pulmonary infiltrates may be due to infection, pulmonary hemorrhage, pulmonary edema or drug-induced lung injury. Among these, pulmonary toxicity caused by antineoplastic agent is being recognized more frequently. Cyclophosphamide, an alkylating cytotoxic drug, is used widely in the treatment of malignancies including lymphoma. The incidence of pulmonary toxicity is probably less than 1 percent, and its relation with total dosages and schedule of the drug is not yet defined. The typical pictures of cyclophosphamide-induced pulmonary toxicity are non-productive cough, dyspnea, fever, hypoxemia with respiratory alkalosis and interstitial pneumonitis. However, relatively infrequent pulmonary toxicity of cyclophosphamide and frequent development of infectious pulmonary infiltrate in the patients treated with chemotherapy may hamper the early diagnosis of cyclophosphamide toxicity. Interstitial pattern and unresponsiveness to antibiotics of the pneumonitis might be the clues of suspicion. The best ways to treat the patients with cyclophosphamide toxicity are early diagnosis, discontinuation of the drug and early corticosteroid trial, although usefulness of steroid has not been firmly established. Recently, we experienced three cases of interstitial pneumonitis developing during cyclophosphamide-containing chemotherapy for non-Hodgkin's lymphoma in the absence of neutropenia or thrombocytopenia. Early use of corticosteroid in later two cases could resolve the pulmonary complication completely, whereas the pneumonitis failed to improve in spite of the massive use of multiple antibiotics in the first case.