Giant cell pneumonia is an atypical fatal measles infection affecting children with altered immunologic status and is usually diagnosed postmortem by demonstration of multinucleated giant cells. Seven pediatric cases of Hecht's pneumonia, which account for 3% of all pneumonia cases in the ten-year Hacettepe pediatric necropsy series, have been diagnosed by light microscopic examination. In addition, in one case, the measles antigen was demonstrated in a direct immunofluorescent study. In three cases there was no clinical evidence of measles. As an underlying disease and/or associated condition, there was thymic dysplasia in four patients, tuberculosis in two and one case each of diabetes mellitus and Hodgkin's disease (in remission under heavy chemotherapy). Clinical features and pertinent histopathologic findings of the lungs and the lymphoid tissues of the patients are mentioned. The increasing frequency of giant cell pneumonia in patients with altered immunologic status is stressed, the literature concerning the cytopathologic changes specific for measles is briefly summarized, and suggestions for the prevention of this fatal disease are made.

Keywords: diabetes mellitus, giant cell pneumonia, Hecht's pneumonia, Hodgkin's disease, measles, thymic dysplasia, tuberculosis, Warthin-Finkeldey giant cells