CHRONOLOGICAL OBSERVATION OF MOUSE ENDOMETRIAL CARCINOGENESIS INDUCEDBY N-METHYL-N-NITROSOUREA AND 17-BETA-ESTRADIOL

Chronological observation of the neoplastic endometrial lesions induce d by N-methyl-N-nitrosourea (MNU) and 17 beta-estradiol (E(2)) were st udied. E(2) induced cystic glandular hyperplasia, but adenomatous hype rplasia was induced predominantly by MNU. Atypical hyperplasia and ade nocarcinoma were induced cooperatively by E(2) and MNU, and first foun d at week 12; the incidence of adenocarcinoma increased in accordance with the week-course. Some atypical hyperplasia might be changed to ad enocarcinoma. Mean AgNORs numbers in (pre)neoplastic lesions increased in accordance with neoplastic changes. This model was useful for clar ifying histogenesis of human endometrial carcinogenesis.