Background: It is quite unusual for a fistula to communicate directly with the surface of the hernia sac, and associated prolapse of the ileum through a patent omphalomesenteric duct is also extremely rare.
Objectives: We report a unique case of a fetus exposed to methimazole in utero, with a hernia of the umbilical cord and associated ileal prolapse through a patent omphalomesenteric duct.
Methods and results: In this case, the umbilical cord was attached to a small unruptured omphalocele, to the right of which a small everted loop of the ileum had evaginated. The hernia sac measured 2.5 cm and contained only ileum. The ileal prolapse was T shaped and had two visible mucosal ostia, and meconium was discharging from the ostium on the oral side. We confirmed that this loop of small bowel had prolapsed through a patent omphalomesenteric duct, which had a fistulous communication with the surface of the hernia sac. This resulted in the misleading prenatal findings on ultrasound and MRI, which were suggestive of a gastroschisis. Such a case with prenatal ultrasound and MRI findings has not been reported previously.
Conclusion: The observed congenital anomaly in our fetus might be associated with prenatal exposure to methimazole.
(c) 2009 S. Karger AG, Basel.