Vaginal tumors in mice from methylcholanthrene and prenatal exposure to diethylstilbestrol.

To test the hypothesis that mice exposed prenatally to diethylstilbestrol (DES) develop adenocarcinomas due to sensitivity of vaginal and cervical adenosis to carcinogens, sponges impregnated with methylcholanthrene (MCA) were lodged against the cervix and vaginal fornices of 6-month-old strain CD-1 mice exposed prenatally to DES. Only squamous cell carcinomas developed in these mice, but at a significantly higher rate than in MCA-treated mice not exposed prenatally to DES. An adenosquamous carcinoma and a precursor of adenocarcinoma developed in DES-exposed mice with control sponges.