Abstract
Endometrioid Stromal Sarcoma (ESS) is an uncommon tumour that occurs in women over wide age range of 11 years to 76 years accounting for only 0.2% of all uterine malignancies and for 15%-26% of primary uterine sarcomas. These tumours arising from ovary are extremely rare. Most of them are associated with nulliparous or perimenopausal women. It is commonly associated with endometriosis of the ovary. Here we present this rare case to emphasize on the uniqueness and histomorphology of ovarian ESS in patients with endometriosis.