High-grade serous carcinoma arising in postmenopausal ovarian endometrioma: A rarely encountered case

Abstract

Epithelial ovarian serous cancer arising in endometrioma is an uncommon phenomenon. Here, we present a case of postmenopausal ovarian high-grade serous carcinoma associated with ovarian endometrioma. A 64-year-old woman attended the clinic with pelvic pain and persistent vaginal discharge. Ultrasonography revealed an endometrial thickness and 37*23 mm left cystic adnexal mass. During the operation, solid pelvic mass grossly located in the cul-de-sac infiltrating rectum and left ovarian cysts were observed. At the intraoperative frozen section, benign left adnexal mass, benign pelvic lymph nodes, and the morphological findings of adenocarcinoma with undetermined-site of the origin were detected in the uterus and rectosigmoid colon. Final pathology revealed a high-grade ovarian serous carcinoma arising in ovarian endometrioma from two microscopic focuses. In sum, when we encounter postmenopausal endometrioma with increased biomarkers, it is crucial to consider the possibility of malignant transformation to ovarian cancer.