Teaching Case

Fleshy inflamed bud of the umbilicus associated with a permeable orifice.

The patient had a 2cm2 fleshy bud of the umbilicus, which became red and swollen. A little orifice was detected within the umbilicus. An iodine investigation of this umbilical anomaly was requested. Water-soluble contrast material was easily injected via a thin probe introduced into an umbilical opening.
The diagnosis of a patent omphalomesenteric duct (POMD) was established, when contrast injection opacified the ileum and the caecum (Figs 1a,b).
When the probe was withdrawn, a later film demonstrated upstream from the vitelline (omphalomesenteric) duct, a small out-pouching of the ileum, filled with contrast material. Diagnosis was made of an associated Meckel's diverticulum (Fig. 1c).
The most likely diagnosis was a POMD of the Meckel's diverticulum.
A contrast material-enhanced gastrointestinal study, performed immediately after fistulography, did not find any other mid-gut abnormalities.
A transumbilical resection of the Meckel's diverticulum and the omphalomesenteric duct was performed. The postoperative course was excellent.

Umbilical remnant malformations result from incomplete closure of either the allantois or the vitelline duct. In cases of incomplete obliteration of the omphalomesenteric duct, several abnormalities have been reported (1), such as an umbilical polyp, a vitelline sinus, a vitelline cyst or fistula and a Meckel's diverticulum.
Meckel's diverticulum is a persistence of the proximal end of the vitelline duct, which normally regresses between the 5th and the 8th embryonic weeks. It has a frequent occurrence (found in 2% of the population) and it is often sought radiologically, but seldom found. Yamaguchi et al. report only 6% of preoperative diagnoses among 600 Meckel's case reports (2). The Meckel's diverticulum represents more than 80% of all omphalomesenteric duct abnormalities. The differential diagnosis of Meckel's diverticulum on small bowel enema is midgut duplication, which is recognised by its mesenteric border implantation, while Meckel's diverticulum is located on the antimesenteric border of the ileum (2).
The most frequent complications of a these diverticula are bleeding, inflammation and small bowel obstruction (2). Neoplasms may be discovered within the diverticulum.
This is a rare case of a Meckel's diverticulum open at both umbilical and ileal ends, the POMD representing the link between the umbilicus and the ileum via the diverticulum. The POMD occurs in 15% of omphalomesenteric duct anomalies (3). Faecal fistulas through the umbilicus, umbilical tumefaction, small intestinal obstruction (4), inflammation and intussusception of the ileum at the umbilicus are the most common clinical features of the POMD (3). If the contrast material had filled the bladder of this newborn instead of its ileum, the diagnosis would have been a patent urachus (5), which is the main differential diagnosis of a POMD.
Cross-sectional imaging like CT or US scan, may reveal umbilical remnant abnormalities, but none of these imaging modalities have been used in this newborn.