Gastric Hyperplastic Polyp Associated with Proliferation of Xanthoma Cells Observed by Magnification Narrow-Band Imaging Endoscopy

A case of gastric hyperplastic polyp with proliferation of xanthoma cells is reported. The patient was a 69-year-old man who visited our hospital for further evaluation of gastric polyps. Endoscopic examination of the upper digestive tract revealed multiple hyperplastic polyps in the gastric antrum. There was a pedunculated polyp with whitish yellow granules, 7 mm in diameter, arising from the greater curvature of the antrum. Magnification narrow-band imaging endoscopy (GIF-H260Z, Olympus) revealed long microcapillaries in the polyp but did not reveal disappearance of the mucosal microstructure or irregular branched capillaries. Endoscopic mucosal resection (EMR) was performed. Histological examination of the specimen revealed the lengthened gastric foveolae in the superficial portion and tight sheet of foamy histiocytes in the lamina propria. Diagnosis of gastric hyperplastic polyp with proliferation of xanthoma cells was made. There was no evidence of malignancy. It is necessary to know that a gastric hyperplastic polyp may associate with gastric xanthoma, although such association is very rare.