Lanthanum deposition of the gastric mucosa in a dialysis patient.

A 49-year-old man presented for a screening esophagogastroduodenoscopy (EGD) as part of his registration for a donated kidney transplant. He had been on hemodialysis for 4 years for end-stage renal disease (ESRD) due to diabetic nephropathy. He was taking lanthanum carbonate (LaC) for hyperphosphatemia. A plain abdominal radiograph and CT showed the radiopaque appearance of LaC. EGD disclosed whitish spots resembling xanthomas in the stomach. Biopsies showed deposition of granular crystalline-like material and phagocytosis of these by multinucleated giant cells on HE staining. These histiocytes were positive for CD68. La deposition was suspected because of the long-term oral administration of LaC. LaC is commonly used to treat hyperphosphatemia in patients with ESRD. La deposition on the gastric mucosa presents with various endoscopic findings, including whitish spots, annular whitish mucosa, and diffuse whitish mucosa. The gastric endoscopic findings of La deposition reflect the infiltrated histiocytes and not the LC deposition itself. Our case highlights the importance of recognizing the rare but characteristic imaging findings of gastrointestinal La deposition in hemodialysis patients who are taking LaC.