Cavitation and other atypical manifestations of Pneumocystis carinii pneumonia.

In the 1980s, under the impact of the acquired immune deficiency syndrome, Pneumocystis carinii Pneumonia (PCP) has become the prime infectious manifestation of this condition. In addition to the well-recognized "classic" features of this disease, several unusual manifestations are being recognized with increasing frequency. We presently review and illustrate the following "atypical" manifestations of PCP: (1) interstitial lung responses that include diffuse alveolar damage, bronchiolitis obliterans, interstitial fibrosis, and lymphoplasmacytic infiltrates; (2) striking localized processes frequently exhibiting granulomatous features; (3) extensive necrosis and cavitation; and (4) extrapulmonary dissemination of the disease. Close clinico-pathologic correlation and attention to roentgenographic detail are invaluable aids in arriving at the correct diagnosis.