Heterotopic gastric mucosa of the ileum.

A 70-year-old woman with a history of breast cancer underwent colonoscopy because of a positive fecal blood test. Her physical examination was unremarkable, but her hemoglobin level was 9.9g/dL (normal range 13.5–17.5g/dL). The colonoscope reached to 8cm above the ileocecal valve. In addition to internal and external hemorrhoids, several polypoid lesions measuring 0.3–0.8cm, with surface ulceration, were found in the terminal ileum (●" Fig.1). Histopathological examination of the biopsy specimens taken from these polypoid lesions revealed mucinous glands in the lamina propria that resembled the pyloric glands of the stomach (●" Fig.2). A diagnosis of heterotopic gastric mucosa (HGM) of the ileum was made on the basis of the histological findings. Because of the patient’s poor overall condition and the fact that she had no major complications from the HGM, further observation alone was recommended. Although HGM may occur throughout the alimentary tract, especially in the proximal esophagus, duodenum, and in a Meckel’s diverticulum, it is rarely found in the jejunum and ileum; most cases of jejunal and ileal HGM are diagnosed on the basis of histological results from surgical specimens [1]. HGM usually appears as an “inlet patch” in the upper third of the esophagus, as nodular masses in the duodenum, or as polypoid masses in other parts of the small intestine [2,3]. HGM may be congenital or acquired, but the mechanism remains unknown. Acquired HGM represents replacement of the native mucosa by gastric epithelium because of various inflammatory or peptic processes [1]. HGM is usually clinically silent and does not require treatment; however, surgical intervention can be considered in patients with complications such as bleeding or intestinal obstruction [1]. Therefore, although HGM of the ileum is extremely rare, it should be considered in the differential diagnosis of ileal polypoid lesions.