Abstract
In 300 cases of leukemia and malignant lymphoma, the overall incidence of P. carinii infestation was 5% as compared to a 1% incidence in 110 infants and 0% in 245 consecutive autopsies (excluding newborns and patients with leukemia or lymphoma). Gomori'' s methenamine silver staining is recommended as a routine procedure in the examination of lung tissue in all cases of leukemia and malignant lymphoma. The recognition of P. carinii infestation will increase significantly with this technique.