EP23.22: Endometriosis related carcinoma: a case report of a mesonephric adenocarcinoma of the ovary

Mesonephric adenocarcinoma is a rare cancer of the female genital tract that comprises less than 1% of all gynecological malignancies and it's typically located in the uterine cervix. According to literature when this tumour occurs in the ovary, it is often associated with endometriosis. We present the case of a 76 years old woman, referred to our ultrasound clinic for pelvic pain, with a long history of endometriosis followed up by a private gynecologist. A transvaginal ultrasound showed in the right adnex a unilocular-solid cyst of 59x54x54 mm, with a solid component of 41mm with irregular margins and moderate vascularization (colour score 3). The cyst was attached to the right uterosacral ligament. Oncological marker levels were: CA125 98.2 U/ml, HE4 208 pmol/L. On subjective evaluation and considering the patient's medical history, an initial diagnosis of endometriod carcinoma of the ovary was made. In January 2024 a hysterectomy with bilateral adnexectomy was performed with recto-sigma resection, due to the presence of massive adhesions between the right adnex, the right uterosacral ligament and the bowel. Final pathology reported multiple foci of deep endometriosis within the uterus. The right ovary showed glandular growth and the molecular features of mesonephric adenocarcinoma. The patient is now undergoing chemotherapy with 6 cycles of carboplatin and paclixatel. Currently, there are no guidelines defining the ultrasound characteristics of ovarian mesonephric carcinoma and the differential diagnosis with other epithelial tumours is based only on morphological and immunohistochemical features; we therefore need to collect more reports to define the ultrasound features of this rare cancer and remember to consider this rare variant as a possible differential diagnosis when a endometrioid cancer is suspected. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.