Xanthoma of the Duodenum

A 55-year-old Japanese man without dyslipidemia underwent esophagogastroduodenoscopy screening. He was diagnosed with reflux esophagitis, atrophic gastritis, and multiple gastric ulcers. In addition, scattered white villi were seen in the superior duodenal angle. No white villi were seen in any other parts of the duodenum. Esophagogastroduodenoscopy performed three months after Helicobacter pylori eradication showed the white villi to still be present in the duodenum (Picture A and B). Close-up observation with narrow-band imaging revealed the presence of slightly swollen, white villi (Picture C). The margin of each white villus could be clearly visualized. A histological examination showed foamy cells in the duodenal mucosa (Picture D, × 20, arrow; Picture E, ×40) that were positive for CD68 (Picture F, ×20, arrows), suggesting they were histiocytes. As a result, a diagnosis of duodenal xanthoma was made. Xanthoma, also known as xanthelasma, is generally seen in the stomach in association with H. pylori infection. Conversely, xanthoma is quite rare at extragastric sites (1-3). Although the distinct pathogenesis, biological significance, and clinical characteristics of extragastric xanthoma have not yet been fully determined, unlike cutaneous xanthoma, no association with congenital and acquired hyperlipidemia has so far been identified (4).