BILATERAL GRANULOSA/THECA CELL TUMOR IN AN AGED RAT

A malignant granulosa cell tumor and a benign granulosa/theca cell tumor were found in a 124-week-old Sprague-Dawaley female rat. These ovarian tumors were deemed to be estrogenically active because of the presence of severe adrenal peliosis. Pituitary prolactinoma and mammary adenocarcinoma were also found. Sex hormones were not measured, but the concomitant occurrence of ovarian, pituitary, and mammary tumors suggested that estrogen derived from ovarian tumors could have induced prolactinoma and that prolactin derived from the pituitary tumor could have been an important factor in producing the mammary adenocarcinoma.