A rare case of extraovarian granulosa cell tumor presenting as a retroperitoneal mass.

Introduction: Granulosa cell tumors (GCT) are the most common malignant sex cord—stromal tumors of the ovary . Rarely, they can occur at extraovarian site with very few cases mentioned in literature. Case history: A 45 yr old lady presented with pain abdomen and on ultrasonography, bilateral ovarian cyst was found. Patient underwent total abdominal  hysterectomy with bilateral salpingoophorectomy and during surgery, a retroperitoneal mass was discovered which was excised. On gross examination, the mass measured 7x5x5cms, was solid with areas of hemorrhage and focal areas of necrosis . Microscopy showed solid sheets of cells with round to ovoid nuclei and scanty cytoplasm. Some of the cells showed nuclear grooves. A diagnosis of extraovarian adult granulose cell tumor was madeand immunostaining with inhibin was positive. Conclusion : Extraovarian granulosa cell tumor needs to be kept in mind in a female patient with a retroperitoneal mass. This case is presented due to its rarity and also to emphasise the fact that these tumors are often missed in the pre operative evaluation of patients and need histopathology for proper diagnosis.