Endometrioid adenosarcoma of the bladder arising from endometriosis

Vesical endometriosis is an uncommon entity characterized by the deposition of benign, hyperplastic endometrial tissue in the bladder. To date, only about 160 cases have been reported in the world literature. More uncommon, however, are case reports of extrauterine malignancies arising from pre-existing endometriosis. We report a case of a large endometrial adenosarcoma in a patient who had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy 10 years previously for endometriosis. To our knowledge this malignancy has never been reported previously to involve the bladder. We review the pathological findings, possible mode of entry into the bladder and current concepts in its treatment.