Extra-uterine low grade endometrioid stromal sarcoma arising from ovarian endometriosis: a case report and review of the literature

BACKGROUND: Endometrial stromal sarcoma (ESS) is a rare neoplasm accounting for only 0.2% of female genital tract tumors. The primary extra-uterine location of ESS is an extremely uncommon occurrence. CASE PRESENTATION: We present a case of a 64-year-old woman presenting with abdominopelvic and bilateral ovarian tumors with misleading clinical presentation and diagnostic challenge. The histopathological examination of the resected specimens disclosed the diagnosis of primary extra-uterine ESS arising from ovarian endometriosis. Adjuvant therapy with an aromatase inhibitor drug was prescribed for the patient, and she is still alive with no evidence of disease 7 months after surgery. CONCLUSION: The awareness of the potential extra-uterine location of ESS should lead to correct diagnosis as this tumor has histopathological features and clinical behavior similar to its uterine counterpart.