Esophageal xanthoma with nearby coexistent squamous cell carcinoma observed using magnifying endoscopy with narrow-band imaging

We report the case of a 63-year-old man who underwent annual surveillance esophagogastroduodenoscopy, during which a small squamous cell carcinoma and a tiny yellowish granular lesion were found in the middle esophagus, slightly apart from each other. Magnifying endoscopy with narrow-band imaging of the yellowish granular lesion showed yellowish spots and blots scattered within an approximately 2-mm area. The larger spots appeared nodular and were overlaid with tortuous microvessels. Subsequently, both the lesions were excised en masse via endoscopic submucosal dissection, and the yellowish lesion was determined to be xanthoma. Histologically, an aggregated nest of foam cells surrounded by intrapapillary capillary vessels filled the intraepithelial papillae; the foam cells also extended inferiorly, below the rete ridges, and were sparsely distributed through the lamina propria mucosae. To our knowledge, the latter finding is the first to be described in literature, which leads us to postulate that the number of foam cells in the lamina propria mucosae may affect how thick and yellow a xanthoma appears on endoscopy. We believe that this case that presents a highly detailed comparison between endoscopic and histologic findings improves our understanding of the endoscopic appearance of esophageal xanthomas and may facilitate a precise diagnosis of this rare disease.