Heterotopic fundic and pyloric-type gastric mucosa in the rectum presented as a foveolar hyperplastic polyp

Abstract

Heterotopic gastric mucosa has been identified in all levels of the gastrointestinal (GI) tract. However, the finding of heterotopic gastric mucosa in the rectum is rare. We report a rare case of a 48-year old male with heterotopic fundic and pyloric-type gastric mucosa in the rectum incidentally found by sigmoidoscopy. A sessile polyp measuring 1.3 cm in diameter is surrounded by whitish discolored area measuring 3.0 cm in diameter. Histologic examination of the biopsy from the whitish discolored area demonstrated fragments of rectal mucosa with heterotopic fundic and pyloric-type gastric mucosa, whereas histologic examination of the biopsy from the rectal polyp showed fragments of heterotopic pyloric-type gastric mucosa with foveolar hyperplasia, which can explain the polypoid appearance. No intestinal metaplasia or Helicobacter pylori are identified. Our case is unique in that the lesion appeared as a polyp due to the foveolar hyperplasia.