1402 terus didelphus is one of the anomalies that may occur as a result of Mullerian duct non-fusion. When complete, the patient has 2 uteri, 2 cervices but the vagina may be single or double. Its incomplete forms may present with varying symptoms and signs. When vaginal septum is incomplete, menstrual efflux may be blocked either at the introitus or at any level up to the cervix. We present a case whose main characteristic is a transverse vaginal septum, which caused most of the presenting symptoms. Case Report. A 15-year-old girl presented to King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia, complaining of intermittent left loin pain of 10-months duration with increased severity during menstruation. She reached menarche at 13- years-old. She experienced severe disabling dysmenorrhea, whose intensity increased progressively with each cycle. Her menstrual cycles were regular, bleeding for 7 days out of 28 on examination, she was found to be a well developed U Uterine didelphus with obstructed hemivagina Malak M. Al-Hakeem, MD, ABOG, Samir A. Ghourab, MD, FRCOG, Mohammed R. Gohar, MD, FRCOG, Tariq Y. Khashoggi, MD, ABOG. ABSTRACT young lady. Her secondary sexual characteristic was normally formed. There were no abnormalities in her respiratory and cardio vascular systems, abdominal examination did not reveal any palpable masses, inspection of the introitus did not reveal any bulge as one would expect in most cases of hematocolpus this turned out to be due to the fact that the obstructing septum was transverse and high in the left lateral aspect of the vagina. Ultrasound scan was performed, this suggested the presence of bicornuate uterus with a hematocolpus in the left cornua. Later, magnetic resonance imaging (MRI) was performed with (T1 and T2 WI obtained in the sagittal, coronal T1 fat- saturated post Gadolinium) and this showed double uterus with 2 cervices and duplication of the vagina. It also revealed left hematocolpus. Intravenous pyelogram revealed normal right kidney and absent left kidney. With collection of the history, physical examination and radiological investigations, a provisional diagnosis of uterus didelphus with 2 cervices and 2 vaginas was made, we felt that the From the Department of Obstetrics & Gynecology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia. Received 26th March 2002. Accepted for publication in final form 8th June 2002. Address correspondence and reprint request to: Dr. Malak M. Al-Hakeem, Assistant Professor and Consultant, Department of Obstetrics & Gynecology, King Khalid University Hospital, PO Box 8413, Riyadh 11662, Kingdom of Saudi Arabia. Tel. +966 (1) 4670818. Fax. +966 (1) 4679347. E-mail: kmmtmm@hotmail.com Complex congenital anomalies of the mullerian ducts can occur in isolation or in association with other developmental disorders. They result from non-development or non-fusion of the mullerian ducts or the failure of reabsorption of the uterine septum. Early diagnosis is necessary to relieve symptoms, optimize preservation of the genital organs and prevent the development of endometriosis. We present a case report to highlight this phenomenon. Saudi Med J 2002; Vol. 23 (11): 1402-1404 Case Reports