Sex cord-stromal (granulosa cell) tumor in an ovotestis from a cow

Development of gonadal tumors within an ovotestis is rare in mammals and this disturbance was not reported in cows. We report herein a gonadal stromal (granulosa cell) tumor in an ovotestis of a 15-month-old heifer from which the reproductive tract was obtained from a local slaughterhouse. Histopathological evaluation revealed that the gonads were ovotestis, but also a coincidental sex cordstromal (granulosa cell) tumor. The sex chromosome type was determined to be XX, suggesting an XX ovotesticular disorder of sexual development with uterus and a female phenotype. Key clinical message: Disorders of sexual development are common in mammals. Gonadal tumors in disorders of sexual development are rarely reported and have not been reported in cows.