Roentgenographically atypical Pneumocystis carinii pneumonia

Two patients with renal transplants were admitted for evaluation of fever. During the course of hospitalization both had hectic fever and arthralgia. Pulmonary symptoms were absent or minimal. In one patient the admitting chest roentgenogram was entirely normal and in the other only a small focal abnormality was apparent. Hypoxemia occurred even in the presence of normal or nearly normal chest roentgenograms. The diagnosis of Pneumocystis carinii infection was made by bronchoscopic brush biopsy in both patients. Therapy with pentamidine isethionate was successful. It is suggested that in patients with renal transplants and in others with similar immonosuppression, even with a normal chest roentgenogram, Pneumocystis carinii infection be considered as the cause of a fever of unknown origin. This should be evaluated initially with blood gas studies; if these are abnormal, further studies, including biopsy, are justified.