Anal protrusion of an ileo-colic intussusception in an adult with persistent ascending and descending mesocolons: a case report

BACKGROUND: Intussusception is one of the less common causes of intestinal obstruction among adults. It is usually covert (concealed) in its clinical presentation. The ileo-colic type with accompanying anal protrusion is extremely rare. The case at hand is that of both an ileo-colic intussusception with anal protrusion, in the presence of a persistence of both the ascending and descending mesocolons; a case possibly yet to be documented in literature. CASE PRESENTATION: A 32 year-old African-Ugandan woman presented with complaints of a mass protruding per anus for 2 weeks. It was reducible and associated with colicky abdominal pain, loose stools, and bloody-mucoid discharge per anus. She had previously had a one and a half month’s history of abdominal pain; periodically continuous, while other times colicky in character. Examination and investigations revealed an intussusception with a partial intestinal obstruction. At laparotomy she was found to have an ileo-colic intussusception with a freely mobile colon throughout its length. There were persistent ascending and descending mesocolons, and absent hepatocolic and splenocolic ligaments. The intussusceptum was ‘milked’ but not completely reducible. A right hemicolectomy was done, with ileo-transverse colonic anastomosis. Histopathological examination revealed no preexisting pathologic lesion as a lead point. CONCLUSION: The persistence of the ascending and descending mesocolons (azygosis) best explains the anal protrusion of an ileo-colic intussusception with partial obstruction. In this case zygosis (normal retroperitoneal ascending and descending colonic positioning) failed embryologically. This experience is particularly beneficial to general surgeons, radiologists, gastroenterologists, colorectal surgeons and pathologists.