Abstract
A classification and morphologic description of primary splenic tumors of guinea pigs is presented for the first time. Twenty glomerate vascular tumors, 15 sinusoidal hemangioendotheliomas, 4 hemangiosarcomas, 2 chondromatous and 5 lipomatous tumors with or without fibrous or vascular components were encountered in the spleen of male and female guinea pigs of 2 inbred strains and one noninbred stock. Foci of cellular arrangements distinctive for splenic tissues were observed in every tumor. In 2 additional guinea pigs, hemangiosarcomas were found disseminated in the spleen, liver, lung and kidney; since the splenic origin of these tumors was uncertain, they were not included in this group of primary splenic tumors.
At all levels used, whole body irradiation with X-or gamma rays increased the rate of occurrence and the number of splenic tumors. A significantly greater number of splenic tumors developed in the irradiated than in the untreated inbred guinea pigs after the age of 30 months. In the irradiated noninbred guinea pigs significantly fewer splenic tumors occurred than in the guinea pigs of the inbred strains.