title: Hernia of the umbilical cord and associated ileal prolapse through a patent omphalomesenteric duct: prenatal ultrasound and MRI findings.
abstract: 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.
  
  
  OBJECTIVE
  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.
  
  
  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.
  
  
  CONCLUSIONS
  The observed congenital anomaly in our fetus might be associated with prenatal exposure to methimazole.
authors.affiliation: Department of Obstetrics, Center for Perinatal Medicine, Nagano Children's Hospital, Nagano, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ono
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Keiko Miyachi
authors.initials: KM
authors.lastname: Takikawa
authors.forename: Takehiko
authors.initials: T
authors.lastname: Hiroma
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yoshizawa
authors.forename: Sorahiro
authors.initials: S
authors.lastname: Sunagawa
authors.forename: Kimiyo
authors.initials: K
authors.lastname: Takagi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Momose
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D020139:Gastroschisis / Q000000981:diagnostic imaging; D006554:Hernia, Umbilical / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D007077:Ileal Diseases / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D011391:Prolapse; D016216:Ultrasonography, Prenatal; D014816:Vitelline Duct / Q000002:abnormalities* / Q000000981:diagnostic imaging