Endometrioid adenocarcinoma in urethrovaginal septum: a diagnostic pitfall

Primary endometrioid adenocarcinoma developed at urethrovaginal septum has not been reported. A 61-yr-old woman presented with recurrent urinary tract infection. She had received hormone replacement treatment with estrogen and progesterone for 5 yr. A pinpoint ulceration at slightly elevated anterior vaginal wall was found and biopsy revealed endometrioid adenocarcinoma. Magnetic resonance imaging showed the 4.3 cm sized mass in urethrovaginal septum. She has undergone anterior pelvic exenteration, pelvic lymph node dissection, and urostomy with ileal conduit. Microscopic finding of the pathology revealed endometrioid adenocarcinoma. Co-existence of endometriosis was not identified. Tumor at urethrovaginal septum was difficult to be detected till growing to be bulky, because of vaginal axis, misunderstanding of the tumor as symphysis pubis, no definitive symptom, and its rarity. This is the first reported case of extraovarian endometrioid adenocarcinoma developed at the urethrovaginal septum. Understanding normal functional anatomy and meticulous physical examination are essential to detect this rare tumor in the urethrovaginal septum.