LAUSR

BACKGROUND Well-differentiated papillary mesothelioma (WDPM) is a rare tumor of unknown malignant potential. It is typically diagnosed incidentally during benign gynaecologic surgery. We report the first published case of WDPM in a woman with synchronous serous carcinomas of the gynaecologic tract and highlight lessons learned for general gynaecologists and gynaecologic oncologists alike. CASE A 62-year-old woman was referred for assessment and management of a pelvic mass. Intraoperatively, metastatic high-grade carcinoma was identified and the patient underwent a successful debulking procedure that identified 3 synchronous tumors: ovarian high-grade serous carcinoma, endometrial serous carcinoma, and 2 foci of pelvic WDPM. CONCLUSION This case of WDPM with 2 synchronous serous gynaecologic tumors is a novel addition to the reported literature and offers many learning points about the disease. Gynaecologic surgeons should be familiar with WDPM, as it is predominantly found in reproductive-aged women undergoing benign gynaecologic surgery, may be linked with endometriosis, and has an unclear malignant potential. Multidisciplinary care is essential for accurate diagnosis. Further research is needed to clarify the optimal management and surveillance of WDPM.