A histopathologic study was performed to evaluate the distribution and evolution of pulmonary lesions associated with Pneumocystis carinii infection in children dying with cancer. Of 520 lungs examined at autopsy, 37 harbored P. carinii. In 19 of the 37 patients the terminal event was Pneumocystis carinii pneumonitis. P. carinii was found in the lungs of 18 children who died from causes other than P. carinii pneumonitis. Evaluation of the clinicopathologic data indicates the following sequence of events in the histopathogenesis of this disease: (1) an initial asymptomatic infestation phase during which cyst forms of P. carinii are visible within alveolar cell cytoplasm; (2) a clinically symptomatic phase during which time parasitic replication is at a maximum; and (3) a final phase in which P. carinii is destroyed by the host. Pulmonary alveolar septal fibrosis may develop following recovery from the acute phase of this disease. Patients with lymphoreticular malignant disease incur a higher risk of developing P. carinii pneumonitis than those with solid tumors or non-neoplastic diseases.
ASJC Scopus subject areas
- Pathology and Forensic Medicine