A morphologic classification and incidence of spontaneous ovarian neoplasms in three strains of mice.

Ovarian tumors were reviewed and classified in 5,404 control inbred BALB/c, C57BL/6, and C3H mice. In descending order of frequency, the most common types in the C3H mice were the tubular mesothelioma (adenoma), thecoma, luteoma, granulosa cell tumor, and cystadenoma. In descending order the most common types in the BALB/c mice were the luteoma, tubular mesothelioma, granulosa cell tumor, thecoma, and cystadenoma. The tubular mesothelioma was the only ovarian tumor of significance in the C57BL/6 mice. Most of the ovarian tumors were rare before 1 year of age, but they increased with age after 1 year.