Spontaneous ovarian neoplasms of the laboratory rat.

A wide range of spontaneous tumors of the ovary are reported in a group of 5903 aged female Sprague-Dawley rats of the CD and CFY strains examined since 1978 in this laboratory. The most commonly observed tumor was the tubular adenoma. Others recorded were tubular adenocarcinoma, papillary cystadenoma, papillary cystadenocarcinoma, a Sertoli's cell tumor, benign and malignant granulosa cell tumors, benign thecal cell tumors, and classical mesotheliomas of ovarian origin. A system of classification and nomenclature of the ovarian tumors from this group is advanced.