Indian Pediatrics 2001; 38: 1317  

Urorectal Septum Malformation Sequence

A 12-hour term baby weighing 2 kg born of a non-consanguineous marriage, was brought because of abdominal distension and abnormal genitalia. The external genitalia consisted of a flat well-circumscribed globular structure with no openings. A normal anal opening was present (Fig. 1). The abdomen was hugely distended, with a palpable mass in the hypogastrium, arising from the pelvis, smooth, firm, 10 × 13 cm size. Systemic examination was otherwise normal; there were no dysmorphic features. Abdominal sonogram showed a midline mass with fluid levels and hypo-echoic areas; the echotexture and cortico-medullary pattern of the kidneys were altered. The radiologist suspected a dermoid or meconium cyst with dysplastic kidneys. An emergency laparotomy was done to make a bladder outlet and to explore the abdomen. Per-operatively, the baby was found to have urethro-vaginal agenesis, a recto-uterine fistula, and a huge distended uterus filled with meconium. The baby’s karyotype was 46XX.

Urorectal Septum Malformation Sequence is mostly found in females. In the 6th week of intrauterine development the urorectal septum fuses with the cloacal membrane, dividing the cloacal cavity into a urogenital sinus anteriorly and a rectum posteriorly. The membrane then breaks down, leaving an open urogenital sinus and rectum. The urorectal septum malformation sequence occurs when the urogenital septum fails to unite with the cloacal membrane; the absence of a proper urogenital sinus thus blocks subsequent development of normal external genitalia. There is striking ambiguity of the external genitalia; the vaginal, urethral and anal openings are absent; vaginal, bladder and rectal fistulae are common. An unusual variation in this case was the presence of a normal anal opening.

M.S. Sudheer,
Philomena Pereira D’souza,
Goa Medical College, Bambolim,
Goa 403 202, India.
E-mail: [email protected]

Fig. 1. Note the distension of the abdomen, ambiguous genitalia and normal anal opening.