[Perforated duodenal diverticulum: report of a case].

After the colon, the duodenum is the most common site of diverticula. Duodenal diverticula can be divided into two types: intraluminal or extraluminal. The latter are more frequent, with a prevalence ranging from 0.6 to 27% in relation to the diagnostic methods utilized. Females are more often affected than males. About 70-75% of extraluminal duodenal diverticula are located in a circular area centred around the ampulla of Vater within a radius of 2-3 cm; these are defined as periampullary or juxtapapillary. Perforation is the rarest type of complication and can simulate different clinical conditions. CT plays a fundamental role in diagnosis also in relation to the different diverticular topography. Perforation is an indication for emergency surgery. The authors describe the clinical case of a duodenal diverticulum containing the outlet of the papilla, complicated by perforation; CT showed retroduodenal fluid and free air. Emergency surgery with an external biliary drainage, naso-biliary probe, and a diverticulo-jejunostomy on a Roux-en-Y defunctionalised loop, resolved the condition.