Case Report: A patient with lynch syndrome with vaginal endometriosis-associated malignancy and synchronous colonic tubulovillous adenoma.

Endometriosis is a common gynecological condition. However, endometriosis-associated malignancies occur in up to 1% of women with endometriosis. Most cases of endometriosis-associated malignancy occur in the ovary, whereas 20% of cases occur at extragonadal sites. Herein, we report the case of a patient with an incidental finding of vaginal endometriosis-associated malignancy who was later diagnosed with Lynch syndrome due to MSH6 deletion with loss of protein expression and was subsequently found to have a high-grade colonic tubulovillous adenoma. The patient was a 50-year-old (Para 2 + 2) woman without any previous history suggestive of adenomyosis or endometriosis, who was examined at a local hospital and was found to have swelling in the posterior vaginal fornix. Colposcopy was performed, and the mass was biopsied, revealing endometrial adenocarcinoma. She was then transferred to our hospital, where, after a series of assessments, she underwent surgery (including total hysterectomy, double adnexectomy, partial vaginal hysterectomy, and lymph node dissection). A postoperative pathological examination indicated a diagnosis of vaginal endometriosis-associated malignancy. A paclitaxel/carboplatin (TC) regimen (paclitaxel 175 mg/m