Endometriosis Malignant Transformation Review: Rhabdomyosarcoma Arising From an Endometrioma

Background: Endometriosis is a widely known benign disease, but 0.5%-1% of cases are associated with malignancy. It has been linked with ovarian neoplasms, particularly endometrioid and clear cell adenocarcinoma histology. Rhabdomyosarcomas are rarely associated with endometriosis.

Case: A 35-year-old patient underwent surgical management of endometriomas to optimize infertility treatment. She later developed abdominal pain with rapid recurrence of ovarian masses. This prompted additional surgery with biopsies diagnosing ovarian rhabdomyosarcoma. Retroactive review of pathologic specimens from her prior surgery demonstrated the neoplasm originated from her prior endometrioma. Focal areas suggested possible underlying ovarian adenosarcoma with stromal overgrowth.

Discussion: The incidence of rhabdomyosarcoma arising from endometriosis is exceedingly rare. The accuracy of diagnosing endometriosis and ruling out neoplasm requires coordinated efforts of a multidisciplinary team, involving radiologists, pathologists, oncologists, and gynecologic surgeons.