Tumors induced in mice by N-methyl-N-formylhydrazine of the false morel Gyromitra esculenta

formylhydrazine (MFH) in drinking water to 6-week-old outbred Swiss mice for Iife produced tumors of the Iiver, lung, gallbladder, and bile duct. The incidences of tumors in these four tissues were 33, 50, 9, and 7%, whereas in the untreated controls they were 1, 18, 0, and 0%, respectively. The higher dose (0.0156% MFH) given under identical conditions had no tumorigenic effect, since it proved too toxic for the animals. Histopathologically, the lesions were classifled as benlgn hepatomas, Iiver cell carcino-mas, adenomas and adenocarcinomas of the lungs, adenomas of the gallbladder, cholangiomas, and cholanglocarclnomas. Since the edible false morel Gyromitra esculenta contains a high amount of MFH, the human population should be dissuaded from consumption of this dangerous mushroom.-J Natl Cancer Inst 60:201-204,1978. One of the often-sought, desirable, edible wild mush