[A case of lipoma of the stomach prolapsing into the duodenal bulb and causing a duodenal ulcer].

We report a case of lipoma in the antrum of the stomach which prolapsed into the duodenal bulb and caused a duodenal ulcer, which was speculated to have been induced by the friction of its tip against the duodenal mucosa. Although the duodenal ulcer healed after the administration of a proton pump inhibitor, the symptoms of epigastric discomfort continued, which was suggested to be due to the prolapse. Therefore, a laparoscopic operation was conducted. The incidence of lipoma of the stomach is rare, and cases of its prolapse into the duodenum are few. Furthermore, it is extremely rare for it to cause a duodenal ulcer. Because these features made this case clinically interesting, we report it here.