Granulosa cell tumor presenting with ovarian torsion and de novo borderline mucinous ovarian tumor in the contralateral ovary.

The authors report a case of 25-year-old women with a rare acute presentation of granulosa cell tumor (GCT) as an ovarian torsion. Right salpingoo-ooferectomy was performed. The pathological diagnosis was GCT One month after the surgery there was a three-cm ovarian cyst in the contralateral ovary and the tumor size increased to six cm in diameter in the following month. Serum inhibin-B levels progressively increased. Cystectomy was performed to contralateral ovary as frozen-section examination indicated mucinous tumor. Final histopathological examination revealed borderline mucinous tumor. Regarding her request, the patient was reoperated again and unilateral oophorectomy and hysterectomy were performed. Clinicians must be aware of the possibility of an underlying malignancy associated with adnexal torsion even in young patients. Frozen section will be helpful in order to avoid incomplete surgeries. Cyst rapidly growing in the ovary in young women should raise the suspicion of a de novo malignancy.