Gastric outlet obstruction caused by a heterotopic pancreas in a pregnant woman: report of a case.

A 26-year-old Japanese woman who was 23 weeks pregnant presented with nausea, vomiting, and abdominal pain. Gastroduodenal endoscopic examination revealed an oval-shaped submucosal tumor obstructing the gastric outlet at the prepyloric area in the stomach. Magnetic resonance imaging showed a 5-cm cystic tumor and we suspected a degenerated gastrointestinal stromal tumor. No other radiological tests were done because of the associated risks to the fetus. Distal gastrectomy was performed and a histological diagnosis of heterotopic pancreas was confirmed. The patient had an uneventful postoperative course and was discharged 19 days after her operation. She delivered a healthy, full-term male infant 3 months later. This case of an ectopic pancreas obstructing the gastric outlet in a pregnant woman is reported and discussed due to its rarity.