Primary Tumors and Adenomatosis Of The Lung In Untreated and In Irradiated Guineá Pigs

Abstract

The morphology of alveologenic tumor, hemangiosarcoma, lymphangioma, intrabronchial papilloma and adenomatosis observed in the lung of guinea pigs is described. Electron micrographs revealed alveologenic tumor to consist of Type II pneumocytes and the lesion of adenomatosis to consist of distended alveoli lined with ciliated bronchial type epithelial cells. A relationship between the dose of gamma or X-ray irradiation received and the frequency of guinea pigs with lung tumors could not be established. In guinea pigs, which survived over 20 months, the frequency of alveologenic tumors in the inbred strains was 23/107 in irradiated and 11/79 in untreated guinea pigs; this difference was statistically not significant. The frequency of tumor bearing inbred males (11/60) was significantly lower than of tumor bearing noninbred males (23/65). In the irradiated guinea pigs alveologenic tumors occurred earlier and tumor nodules in the lung were more numerous than in the untreated guinea pigs. Primary hemangiosarcoma involved the lung of one untreated and one irradiated strain 2 guinea pig. A single lymphangioma was found in an untreated inbred guinea pig. Intrabronchial papillomas were observed twice in irradiated and once in untreated guinea pigs. Adenomatosis was present in the lung of 2 untreated inbred and 5 irradiated noninbred guinea pigs.