Patent omphalomesenteric duct of the vermiform appendix in a neonate: congenital appendicoumbilical fistula.

Umbilical anomalies arise from fetal structures such as the omphalomesenteric duct (OMD) or urachus or from failure of closure of the umbilical fascial ring. Persistence of the OMD may lead to several anomalies including umbilical sinus, umbilical cyst, Meckel's diverticulum, or patent OMD (POMD). A POMD is usually associated with the ileum, but rarely may be with the caecum or appendix. We describe a POMD of the vermiform appendix and discuss the possible pathogenesis and management.