Malignant transformation in endometriosis of the urinary bladder: case report of clear cell adenocarcinoma.

Clear cell adenocarcinoma of the urinary bladder is a very rare neoplasm. This mullerian tumor frequently arises from ovarian endometriosis. We present a case of clear cell adenocarcinoma arising from endometriosis in the bladder; this is only the third such case report in the English language literature. Endometriosis involves the bladder in only approximately 1% of patients with this disease. The patient is a 40 year-old woman who has a history of adenocarcinoma arising from endometrial tissue in the bladder. Her tumor invaded the rectum, necessitating an anterior resection of the rectum as well as a partial cystectomy and a right oophorectomy. This case confirms that the relationship between endometriosis and clear cell adenocarcinomas of the female genital tract extends to the urinary bladder. Carboplatin chemotherapy was initiated in this patient.