Cancer induction in mice by feeding the raw false morel mushroom Gyromitra esculenta.

One of the false morel mushrooms, Gyromitra esculenta, was administered p.o. to Swiss mice that were 6 weeks old at the beginning of the experiment. The mushrooms were fed to the mice for 3 days and were followed by a semisynthetic diet for 4 days each week for life. The treatment induced tumors in the lungs, nasal cavity, blood vessels, forestomach, glandular stomach, cecum, and liver in the following incidences: 80, 10, 50, 16, 4, 28, and 6% in females, and 70, 12, 32, 18, 20, 22, and 12% in males. In the untreated controls, the corresponding tumor incidences were 28, 0, 14, 0, 0, 8, and 0% in females and 38, 0, 6, 0, 0, 8, and 2% in males. The light microscopic examination revealed the typical appearance of adenomas and adenocarcinomas of lungs, adenomas and adenocarcinomas of nasal cavities, hemangiomas and hemangiosarcomas of blood vessels, squamous cell papillomas and carcinomas of the forestomach, adenomas and adenocarcinomas of the glandular stomach, polypoid adenomas and adenocarcinomas of the cecum, and hepatomas. The work demonstrates the carcinogenic action of the raw G. esculenta mushroom.