Carcinogenesis study in mice by 3-methylbutanal methylformylhydrazone of Gyromitra esculenta.

3-Methylbutanal methylformylhydrazone (3-MBMFH) was given to Swiss mice by intragastric instillations at weekly intervals 53 or 2 times at 50 micrograms/g body weight. The treatments induced tumors of the lungs, liver, gallbladder, preputial glands and thyroid. The tumor incidences in the group treated 53 times were 84, 32, 10, 0 and 0% in females, and 76, 38, 6, 48 and 0% in the males, respectively. In the group treated twice the incidences were 38, 0, 4, 0 and 10% in females, and 30, 0, 2, 0 and 6% in males, respectively. The corresponding tumor incidences in the untreated controls were 26, 0, 0, 0 and 0% in females, and 26, 0, 0, 0 and 0% in males, respectively. The light microscopic examination of these neoplasms showed adenomas and adenocarcinomas of lungs, hepatomas and liver cell carcinomas, adenomas and adenocarcinomas of gallbladder, squamous cell papillomas and carcinomas of preputial glands; and, adenomas and adenocarcinomas of thyroid. Gyromitra esculenta mushroom contains 3-MBMFH along with the other hydrazine derivatives. Because at least five ingredients of this fungus exhibit carcinogenic properties, the health hazard implications should be considered.