RESUMO
Virilizing tumors during pregnancy are extremely rare. This case of a 33 year old, gravid 3 para 2, presented with hirsutism and clitoromegaly at 5 months age of gestation. Her past medical and menstrual histories were non-contributory. Ultrasound done during her prenatal check-up at 34 weeks age of gestation revealed an ovarian new growth on the left ovary features suggestive of a benign nature. On her 38th week of pregnancy, LTCS III with right tubal ligation and left salpingooophorectomy were performed and a baby boy weighing 3000 grams without any gross abnormalities was delivered. Histopathologically, the tumor proved to be a benign mucinous cystadenoma. This paper presented an ovarian mucinous cystadenoma with virilizing features that are transient and reversible. Therefore, an ovarian neoplasm should always be considered as a differential diagnosis for causes of virilization during pregnancy.