Urorectal septum malformation sequence: a report of seven cases.

Urorectal septum malformation (URSM) sequence is an extremely uncommon anomaly. We report herein seven cases of URSM sequence that were identified after reviewing all autopsies conducted at our hospital over a period of 26 years (1981-2006). The URSM spectrum includes partial and full URSM sequences. Absent perineal and anal openings with ambiguous genitalia are included under 'full URSM sequence', and a single perineal or anal opening draining a common cloaca with an imperforate anus is called 'partial URSM sequence'. Of our seven cases of URSM, three were full URSM sequence and four were partial URSM sequence. Associated renal anomalies were found in all of the cases. Three cases had unilateral renal agenesis and one each had bilateral renal agenesis and bilateral renal dysplasia, respectively. The remaining two cases had unilateral renal agenesis with contralateral kidney showing features of cystic dysplastic kidney and renal hypoplasia, respectively. Congenital anomalies involving other organs were also found in some of the cases. The longest survival period in our series was 10 days, in accordance with the short survival period usually associated with URSM. Five of the patients were females, one was male, and the sex of one neonate could not be ascertained. One of the neonates was from a twin pregnancy; the other twin was normal.