Introduction
Lanthanum carbonate is one of the widely used phosphate binders, which are orally taken to reduce serum phosphate levels in dialysis patients with chronic kidney disease.1Lanthanum carbonate binds to dietary phosphate and forms insoluble complexes and is excreted in feces, but recently lanthanum carbonate deposition in the gastric and duodenal mucosa has been reported in patients taking them.2-8 In previous studies, the findings of lanthanum deposition with endoscopy in gastric mucosa, white lesions, elevations, erosions, and ulcerations have been usually described in the gastric mucosa. Pathologically, lanthanum depositions usually appear as subepithelial collections of histocytes or small foreign body granulomas, accompanied by intestinal metaplasia, regenerative changes, and foveolar hyperplasia.1,9-11Although some studies have reported that lanthanum deposition and subsequent mucosal changes potentially induce neoplastic lesions, the relationship between lanthanum deposition and carcinogenesis is unknown.11,12
There are few reports of gastric cancer concurrent with lanthanum deposition2,12-14 and surgical resection of gastric cancer concurrent with lanthanum deposition.2,12Furthermore, unlike past resected cases, in this case, it was difficult to clearly distinguish gastric adenocarcinoma from mucosal changes because of its confusing appearance following lanthanum deposition.