[Congenital duodenal diaphragm in an adult associated with an abnormal location of Vater's ampulla: a case report and review of the literature].

Web-related duodenal obstruction in the adult is rare, so is the anomalous location of the ampulla of Vater in the third part of the duodenum. A woman who harboured both anomalies is described and the literature reviewed. The diagnosis, often made at laparotomy, mandates an exploratory duodenotomy. The best treatment consists of partial excision of the web and transverse closure of the duodenum. A duodenojejunostomy or duodenoduodenostomy, or both, are acceptable therapies. The anomalous location of the ampulla of Vater in the third part of the duodenum does not require treatment.