[Pneumocystis carinii infections in patients with neoplasms and AIDS--clinical-pathologic changes in the lungs].

Pneumocystis carinii (PC) has been documented as a cause of pneumonia in a broad range of immunocompromised patients. The presentation of disease will very based on the underlying predisposing condition but a confirmation depends upon the identification of organisms in a bronchial aspiration or lung biopsy specimen. This retrospective study based on autopsies of 15 patients (pts) with AIDS and 12 non AIDS pts with neoplastic diseases. Pneumocystis carinii pneumonia (PCP) was confirmed by histologic examination. The clinico-pathological analysis emphasizes a spectrum of morphologic variation of the disease in relation to the clinical course of a principal disease. A distinction was made between the microscopical diagnosis of PC infection in AIDS and non AIDS pts; the burden of organisms in infected AIDS pts appeared greater than that of neoplastic diseases (mostly with small cell lung carcinoma). Nonspecific features of diffuse alveolar damage associated with PC organisms were identified in 67% of non AIDS pts and 13% of AIDS pts. Various degree of interstitial fibrosis was more prominent in AIDS pts (67%) than in non AIDS pts. The high frequency of atypical changes in lung might be the result of various chemotherapeutic agents used in managing these pts or repeated pulmonary infections.