Clinical Characteristics of Seven Patients with Lanthanum Phosphate Deposition in the Stomach

Abstract

Objective To analyze the clinical characteristics and endoscopic features of patients with lanthanum deposition in the stomach. Patients We retrospectively reviewed seven patients with lanthanum deposition in the stomach who were diagnosed at Okayama Saiseikai General Hospital. We investigated the patient sex, age at diagnosis, medical and medication histories, gastrointestinal symptoms, complications, presence or absence of gastric atrophy, and outcome. We also investigated any changes in the endoscopic features if previous endoscopic images were available. Results Seven patients (six males and one female) had lanthanum deposition. The median age was 65 years (range, 50-79 years). All patients had been undergoing dialysis (continuous ambulatory peritoneal dialysis in one patient, hemodialysis in six patients). The dialysis period ranged from 16 to 73 months (median, 52 months). The patients had all been taking lanthanum carbonate for a period ranging from 5 to 45 months (median, 27 months). Gastric atrophy was noted in 6 patients (85.7%). One patient had difficulty swallowing, and 1 other patient had appetite loss. The other 5 patients were asymptomatic. Endoscopic features included annular whitish mucosa (n = 4), diffuse whitish mucosa (n = 3), and whitish spots (n = 2). Five patients underwent multiple esophagogastroduodenoscopy. The endoscopic features were unchanged in 2 patients, whereas the whitish mucosa became apparent and spread during the course in 3 patients. Conclusion We identified 7 patients with lanthanum deposition in the stomach. All patients showed whitish lesions macroscopically. Although the pathogenicity of gastric lanthanum deposition is uncertain, lanthanum-related lesions in the stomach progressed during continuous lanthanum phosphate intake in several patients.

Keywords: chronic kidney disease; hyperphosphatemia; lanthanum carbonate.

Figure 1.

Pathological images of lanthanum deposition in the stomach. Hematoxylin and Eosin staining shows fine, amorphous, eosinophilic material (A). CD68 staining confirms the existence of histiocytes in all cases (B). On scanning electron microscopy, the deposited material appears bright (C). Energy-dispersive X-ray spectroscopy shows that lanthanum (D) and phosphate (E) distribution is identical to that of the bright areas.

Figure 2.

Endoscopy images. Representative endoscopy images of whitish spots (A, B), an annular whitish mucosa (C, D), and a diffuse whitish mucosa (E). Case 3 has whitish spots (A, arrow), which resemble gastric xanthoma, in addition to a diffuse whitish mucosa (Fig. 5). Similar whitish spots are seen in case 7 (B, arrow). An annular whitish mucosa is seen in case 4 (C, arrow) and case 5 (D, arrow). Case 1 has a diffuse whitish mucosa (E).

Figure 3.

Endoscopic images of case 1. Esophagogastroduodenoscopy performed four months before the start of lanthanum carbonate administration shows no whitish lesions (A, B). After lanthanum carbonate intake for 20 months, a diffuse whitish mucosa appeared in the gastric cardia (C). Round, slightly elevated areas with a reddish part in its center and a whitish part in its periphery are also identified in the antrum (D). Thirty-eight months after the start of lanthanum phosphate prescription, a diffuse whitish mucosa appears to have spread (E) and annular whitish lesions are evident (F).

Figure 4.

Endoscopic images of case 2. Esophagogastroduodenoscopy performed 36 months after the start of lanthanum carbonate intake shows a whitish mucosa in the lesser curvature of the gastric body (A). A diffuse whitish mucosa is more apparent 56 months after lanthanum carbonate intake (B).

Figure 5.

Endoscopic images of case 3. Intestinal metaplasia is seen in the posterior wall of the gastric body (A). Whitish lesions emerged 32 months after lanthanum carbonate intake (B).