Cancer Induction in Mice Methylformylhydrazone of With Acetaldehyde the False Morel Mushroom 1,2,3,4

which occurs up to 0.3 % in one of the edible false morel mush-rooms, Gyromitra escu/enta, was administered to noninbred Swiss mice in propylene glycol in 52 weekly intragastric instilla-tions as 100 J.lg/g body weight. The treatment induced tumors of the lungs, preputial glands, forestomach, and clitoral glands. The tumor incidences in these four tissues in treated females were 70, 0, 16, and 12%, respectively, whereas in the treated males they were 40, 90, 0, and 0%. The corresponding tumor incidences in the solvent control females were 26, 0, 0, and 0%, whereas in the solvent control males they were 22, 0, 0, and 0%, respectively. Histopathologically, the neoplasms were classified as adenomas and adenocarcinomas of the lungs; squamous cell papillomas and carcinomas, adenocarcinomas, undifferentiated carcinomas, an-giosarcomas, and fibrosarcomas of the preputial glands; squamous cell papillomas and carcinomas of the forestomach; and squa