Rare Causes of Gastrointestinal Hemorrhage: A Case Series of Adult Duodenal and Jejunal Gastric Heterotopia.

Gastric heterotopia (GH) is a rare cause of gastrointestinal bleeding. GH of the small bowel is rare, and the duodenum is more commonly involved than the jejunum. Here, we present five cases of GH involving the duodenum and jejunum, with presentations including gastrointestinal bleeding, symptomatic anemia, and no symptoms. A 63-year-old man presented with melenic stools but could not identify an obvious bleeding source during endoscopy. He was ultimately diagnosed with jejunal GH. A 70-year-old woman with melena and severe anemia had a duodenal bulb mass detected during endoscopy, which was histopathologically diagnosed as GH. A 54-year-old woman experienced nausea, vomiting, and dysphagia. Endoscopy revealed esophagitis and a duodenal GH without malignancy. A 69-year-old woman incidentally had duodenal GH during evaluation for a lung mass, which was later diagnosed as an aggressive neuroendocrine tumor. The fifth patient was an 83-year-old woman who was admitted for profound significant anemia. Upper endoscopy showed a round, 0.3 cm ulcer in the duodenum and a duodenal polyp with a tiny ulcer, and her histopathology was consistent with GH. The exact mechanism of the action of GH remains unknown. Its clinical presentation is variable, gastrointestinal bleeding is rare, and diagnosis is based on histopathology only. Our case series emphasizes the need to include GH in the differential diagnosis of patients presenting with gastrointestinal bleeding, with or without other associated symptoms.