Recurrent Pneumocystis Carinii Pneumonia with Long Interval Showing Disparate Radiographic Findings

: A case of recurrent Pneumocystis carinii pneumonia with a long interval between episodes and each episode showing a different radiographic appearance is reported. The radiographic finding in the initial infectious episode was bilateral, patchy, alveolar infiltrate predominantly in the upper and middle lung zones and that in the second infectious episode, six and a half years later, showed bilateral interstitial infiltrate predominantly in the middle and lower lung zones. T cell immunity expressed by mitogen-induced T cell proliferation was clearly different in the two infectious episodes. These differences in radiographic appearance could be due, at least in part, to altered immunological states between the first and second infectious episodes.