The Many Faces of Endometriosis-Related Neoplasms in the Same Patient: A Brief Report.

Introduction: Endometriosis is a common benign gynecological condition that can be associated with a slightly increased risk of developing a wide range of malignancies.

Case Presentation: We herein report a singular case of a 62-year-old woman with a history of pelvic endometriosis, referred to our institution for chronic pelvic pain and uterine bleeding, with clinical and radiological evidence of left ovarian mass of 18 cm in largest diameter and multiple nodular mural lesions of the uterine cavity. The patient underwent exploratory laparotomy followed by hysterectomy, bilateral salpingo-oophorectomy, and omentectomy with pelvic lymph-node sampling. The histological examination of the ovarian mass revealed a clear-cell ovarian carcinoma arising from an endometriotic cyst. The microscopic examination of the uterine cavity showed multiple conventional leiomyomas, diffuse foci of adenomyosis, and a 1.5-cm yellow nodule diagnosed as low-grade endometrial stromal sarcoma associated with glandular atypical differentiation and with extension into parametrial and omental tissues. Following the diagnosis, the patient was treated with chemotherapy, radiation therapy, and hormonal therapy and after 9 months of follow-up is alive without local recurrences and distant metastases.

Discussion/conclusions: To the best of our knowledge, the present case represents the first evidence of the simultaneous occurrence of clear-cell carcinoma and low-grade endometrial stromal sarcoma arising within ovarian and uterine endometriotic foci, respectively.