Lanthanum deposition disease as a cause of gastrointestinal bleeding in a dialysis patient: a case report

Abstract Background Lanthanum carbonate (LC) is a calcium-free phosphate binder widely used in patients with chronic kidney disease, including those undergoing dialysis. Although generally considered safe, rare gastrointestinal side effects, such as lanthanum deposition disease (LDD), have been reported. Case presentation We report the case of a 59-year-old patient undergoing hemodialysis (HD) with diabetic kidney disease who presented with recurrent anemia and melena. Despite extensive gastrointestinal evaluations, including multiple endoscopies and imaging studies, with only gastric erosion detected, the source of bleeding remained undetermined. The patient had been taking LC (1500 mg/d) for 3 years. Upon pathological examination of the gastric biopsies, histiocyte clusters with light-brown granular deposits were identified, which were consistent with gastric LDD. After discontinuation of LC, the anemia resolved, and hemoglobin levels improved. There was no recurrence of gastrointestinal bleeding. Based on these results, we identified gastric erosion associated with LDD as the source of bleeding. Conclusions Clinicians should consider gastric LDD in the differential diagnosis of unexplained anemia in patients taking LC, even in the absence of specific endoscopic findings. Interdisciplinary collaboration and histopathological evaluations are critical for diagnosis and management. Continued vigilance and long-term monitoring are warranted because of the uncertain long-term effects of lanthanum deposition.