Possibility of lanthanum absorption in the stomach

Lanthanum Gastropathy in Gastrectomy Specimen: A Case Report

Lanthanum carbonate (LC) is a phosphate binder used in end-stage renal disease (ESRD) with few adverse effects due to poor systemic absorption. Gastrointestinal deposition is likely due to alterations in epithelial permeability from inflammation in ESRD. It is challenging to detect in cases with minimal deposition and may be missed on endoscopy and biopsy. A 36-year-old with ESRD who was evaluated for gastrectomy was found to have LC deposition histologically. Years later, the excised portion had similar findings. This case allows for evaluation of LC gastropathy in a resection specimen, providing the opportunity to showcase its unique pathology features.

The Effect of Lanthanum (III) Nitrate on the Osteogenic Differentiation of Mice Bone Marrow Stromal Cells

To study the species of lanthanum (III) nitrate (La[NO3]3) dispersed in cell media and the effect on the osteoblast differentiation of bone marrow stroma cells (BMSCs). Different La-containing precipitations were obtained by adding various concentrations of La(NO3)3 solutions to Dulbecco's modified Eagle medium (DMEM) or DMEM with fetal bovine serum (FBS). A series of characterisation methods, including dynamic light scattering, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and protein quantification were employed to clarify the species of the different La-containing precipitations. The primary BMSCs were isolated, and the cell viability, alkaline phosphatase activity, and the formation of a mineralised nodule of BMSCs were tested when treated with different La-containing precipitations. The La(NO3)3 solutions in DMEM could form LaPO4, which exits in the particle formation, while the La(NO3)3 solutions in DMEM with FBS could form a La-PO4-protein compound. When treated with La(NO3)3 solutions in DMEM, the cell viability of the BMSCs was inhibited at the concentrations of 1, 10, and 100 μM at 1 day and 3 days. Meanwhile, the supernatant derived from the La(NO3)3 solutions in DMEM did not affect the cell viability of the BMSCs. In addition, the precipitate derived from the La(NO3)3 solutions in DMEM added to the complete medium inhibited the cell viability of the BMSCs at concentrations of 10 μM and 100 μM. When treated with La(NO3)3 solutions in DMEM with FBS, the derived precipitate and supernatant did not affect the cell viability of the BMSCs, except for the concentration of 100 μM La(NO3)3. The La-PO4-protein formed from the La(NO3)3 solutions in DMEM with FBS inhibited the osteoblast differentiation of BMSCs at the concentration of 1 μM La(NO3)3 (P < 0.05) but had no effect on either the osteoblast differentiation at the concentrations of 0.001 and 0.1 μM or on the formation of a mineralised nodule at all tested concentrations of La(NO3)3. Overall, La(NO3)3 solutions in different cell culture media could form different La-containing compounds: La-PO4 particles (in DMEM) and a La-PO4-protein compound (in DMEM with FBS). The different La-containing compounds caused different effects on the cell viability, osteoblast differentiation, and the formation of a mineralised nodule of the BMSCs. The La-containing precipitation inhibited the osteoblast differentiation by inhibiting the expression of osteoblast-related genes and proteins, providing a theoretical basis for clinical doctors to apply phosphorus-lowering drugs such as lanthanum carbon.

Novel case of laparoscopically resected gastric adenocarcinoma concurrent with lanthanum deposition

A 73-year-old man taking lanthanum carbonate for hemodialysis showed progressing gastric mucosal changes with lanthanum deposition. Regular examination revealed concurrent gastric carcinoma. The extent and depth of its invasion were ambiguous because of the surrounding lanthanum deposition. Furthermore, there could be other potent carcinomas, and curative laparoscopic gastrectomy was performed.

Gastric lanthanosis (lanthanum deposition) in an immunosuppressed patient that discontinued lanthanum carbonate seven years ago

A 72-year-old female patient used the oral phosphate binder lanthanum carbonate for 6 years, before discontinuing it after receiving a pancreas and kidney transplant. Now, 7 years after discontinuation, the patient developed bilious emesis. An upper gastrointestinal endoscopy showed an unspecific gastritis. Biopsies showed subepithelial crystalline deposits consistent with gastric lanthanosis.

Early gastric cancer with lanthanum deposition mucosa by endoscopic submucosal dissection: a case report and literature review

Lanthanum carbonate is used to prevent hyperphosphatemia in dialysis patients with chronic renal failure and generally recognized as poorly absorbed by the gastrointestinal tract. However, some clinical cases of lanthanum deposition in the stomach have been shown. In addition, few endoscopic images of lanthanum deposition have been reported, particularly with respect to early-stage gastric cancer. A 64-year-old man with 22 years history of dialysis was treated with lanthanum carbonate for 3 years. With screening esophagogastroduodenoscopy, he was diagnosed with intramucosal gastric cancer, surrounded by the specific endoscopic images of the lanthanum deposition, and underwent endoscopic submucosal dissection. Histopathologically, massive accumulations of macrophages containing fine, granular, eosinophilic materials were observed in the lamina propria. These eosinophilic depositions were present in the lamina propria of the non-tumor region, but not in that of the tumor region. The histological features were further identified as lanthanum phosphate deposition by scanning electron microscopy. This case indicates the clinical significance of lanthanum deposition associated with gastric cancer. It is further required to evaluate more endoscopic images of the gastric mucosa, especially intramucosal cancer, with lanthanum deposition.

Gastropathy associated with lanthanum phosphate deposition that was endoscopically tracked for 3 years. A case report

Background

With the recent increased use of lanthanum carbonate, several cases of lanthanum phosphate deposition to gastric mucosa in dialysis patients have been reported. However, the endoscopic appearance of the early-stage lesion and the over-time alterations of endoscopic findings due to the progression of lanthanum phosphate deposition remain unclear.

Case presentation

An 80-year-old man receiving dialysis and taking lanthanum carbonate as a phosphate binder over a 4-year period underwent upper gastrointestinal endoscopy four times beginning 1 year after initiation of treatment. The first endoscopic examination (after 1 year of exposure to lanthanum carbonate) revealed rough mucosa with a few areas of white granular mucosa. Over the 3 years of endoscopic follow-up, the white granular mucosa spread and multiple erosions appeared. Histopathological findings of biopsy specimens from an erosion showed extensive infiltration by histiocytes containing deposits. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) revealed that the presence of the deposits containing phosphorus and lanthanum in the gastric mucosa.

On the basis of these results, the patient was diagnosed with gastropathy associated with lanthanum phosphate deposition.

Conclusions

Over a 3-year period, endoscopic findings associated with lanthanum deposition gradually changed and expanded from the early stage.

Lanthanum Deposition in the Gastroduodenal Mucosa of Dialysis Patients

Lanthanum (La) carbonate (LC) is one of the most popular phosphate binders used in dialysis patients with end-stage renal disease. Only a small amount of LC is believed to be absorbed from the gastrointestinal (GI) tract because LC strongly binds to dietary phosphate and forms insoluble complexes. La deposition in the gastroduodenal mucosa has been recently identified. Endoscopically, La deposition is demonstrated as whitish lesions of varying sizes and shapes in the gastroduodenal mucosa. Microscopically, La deposition is characterized by histiocytic reaction or small foreign body granulomas containing gray or brown materials mainly in the lamina propria of the GI mucosa. Some histiocytes containing La can migrate into regional lymph nodes via the lymphatic flow. The amount of La deposition in the gastroduodenal mucosa is correlated with the total dose of LC administration, and La deposition is almost consistently observed in LC-treated dialysis patients. Although the detailed mechanism of La deposition in the GI tract is still unclear, several factors, such as gastric pH and metaplastic change of the mucosal epithelium, may be involved in the La deposition in the gastroduodenal mucosa. Here we present an overview of the feature of La deposition in the GI tract.

Review of the diagnosis of gastrointestinal lanthanum deposition

Lanthanum carbonate is used for treatment of hyperphosphatemia mostly in patients with chronic renal failure. Although lanthanum carbonate is safe, recently, lanthanum deposition in the gastrointestinal mucosa of patients has been reported in the literature. This review provides an overview of gastroduodenal lanthanum deposition and focuses on disease’s endoscopic, radiological, and histological features, prevalence, and outcome, by reviewing relevant clinical studies, case reports, and basic research findings, to better understand the endoscopic manifestation of gastrointestinal lanthanum deposition. The possible relationship between gastric lanthanum deposition pattern and gastric mucosal atrophy is also illustrated; in patients without gastric mucosal atrophy, gastric lanthanum deposition appears as diffuse white lesions in the posterior wall and lesser curvature of the gastric body. In the gastric mucosa with atrophy, lanthanum-related lesions likely appear as annular or granular whitish lesions. Moreover, these white lesions are probably more frequently observed in the lower part of the stomach, where intestinal metaplasia begins.

Case report of lanthanum deposition in the esophagus

A 69-year-old woman had received hemodialysis for chronic renal failure and was taking lanthanum carbonate since 63 years of age. She presented with appetite loss and nausea. We performed esophagogastroduodenoscopy, which revealed multiple longitudinal white plaques in the esophagus. Lesion biopsies showed lanthanum deposition, and lanthanum carbonate was found histologically by energy-dispersive X-ray spectroscopy. The plaques of this patient appeared like those of dabigatran-induced esophagitis, and may have occurred due to long-term contact of the esophageal epithelium with lanthanum carbonate because patient spent time in lying state. Although a few studies regarding lanthanum deposition in the stomach have been conducted, there are no reports on lanthanum deposition in the esophagus. This case suggests that the presence of longitudinal white plaques in the esophagus may indicate lanthanum deposition.

Utility of Scanning Electron Microscopy Elemental Analysis Using the 'NanoSuit' Correlative Light and Electron Microscopy Method in the Diagnosis of Lanthanum Phosphate Deposition in the Esophagogastroduodenal Mucosa

BACKGROUND

We have recently developed the correlative light and electron microscopy of hematoxylin and eosin (H&E)-stained glass slides using the 'NanoSuit' method. The aim of this study is to explore the utility of the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy elemental analysis for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides.

METHODS

Nine H&E-stained glass slides of the upper gastrointestinal tract mucosa containing the brown pigmented areas by light microscopic observation, which were suspected as lanthanum phosphate deposition, were observed and analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy using the NanoSuit-correlative light and electron microscopy method.

RESULTS

In all nine slides, the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy revealed the accumulation of both lanthanum and phosphorus in the tissue area corresponding to the brown pigment deposition. In addition to the existence of lanthanum phosphate in the stomach and duodenum, known target organs, we observed deposition in the esophagus for the first time. Furthermore, we observed lanthanum phosphate deposition in the background mucosa of stomach containing primary adenocarcinoma.

CONCLUSIONS

Scanning electron microscopy-energy dispersive X-ray spectroscopy analysis using the NanoSuit-correlative light and electron microscopy method is useful for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides. Lanthanum phosphate deposition occurs not only in the stomach and duodenum but also in the esophagus.

Distribution of lanthanum carbonate in the gastric mucosa confirmed by electron microscopy with a magnified endoscopy: a case report and literature review

We describe the case of a 70-year-old man with diabetic nephropathy undergoing hemodialysis. Four years following hemodialysis, he started taking lanthanum carbonate 1500 mg/day and lansoprazole 30 mg/day. Nine years following hemodialysis, he underwent screening esophagogastroduodenoscopy, which demonstrated the presence of the whitish cobblestone-like mucosa in the gastric corpus and multiple reddish depressed lesions with annular whitish mucosa in the antrum. With magnified narrow-band imaging endoscopy, a yellowish–white substance was observed in the villous structure, and subepithelial vessels were observed on the yellowish–white substance. Biopsies were taken from the whitish cobblestone-like mucosa of the upper corpus, a reddish depressed part of the antrum. Histologically, aggregates of cells containing amphophilic fine granular material were found in the mucosal interstitium. These cells stained positive for CD68 and were identified as histiocytes. Since he had been taking lanthanum carbonate for 5 years, we considered the possibility of histiocyte-mediated phagocytosis of lanthanum. Digital mapping via scanning electron microscopy with energy-dispersive X-ray spectrometry showed the presence of lanthanum and phosphorus in the interstitium and cytoplasm of histiocytes. The white, rough mucosa in the gastric body appeared 6 months following the commencement of lanthanum administration and still exists 3 years and 5 months after discontinuation of lanthanum.

Frequent Involvement of the Duodenum with Lanthanum Deposition: A Retrospective Observational Study

Objective This study aimed to investigate the endoscopic features of lanthanum-associated duodenal lesions and the prevalence of duodenal involvement among patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Methods We retrospectively reviewed 24 patients with pathologically proven lanthanum deposition in the gastrointestinal tract. Patients were subdivided into three groups: Group A, patients with pathologically-proven lanthanum deposition in the duodenum; Group B, patients without lanthanum deposition in the duodenum; and Group C, patients without a biopsy of the duodenum. Results A biopsy examination of the duodenum was performed in 19 patients, and lanthanum deposition was detected in 17 patients (17/19, 89.5%). In group A (n=17), whitish duodenal villi were detected in 15 patients during esophagogastroduodenoscopy (15/17, 88.2%). While the other two patients showed no whitish villi, a biopsy of the duodenal mucosa revealed lanthanum deposition. The deposition of a white substance showing a clear margin was visible within multiple villi under magnified observation in some patients of group A. Group B patients (n=2) also showed whitish villi. However, the whitish color was faint in one case and sparse in the other case. Conclusion Lanthanum deposits in the duodenum may resemble white villi. However, in some cases, these deposits may be unrecognizable during esophagogastroduodenoscopy due to the subtle degree of deposition. Endoscopists should biopsy the duodenum as well as the stomach, regardless of the presence or absence of white villi, for an accurate determination of lanthanum deposition in the gastrointestinal tract.

Case of early-stage gastric cancer identified in the gastric mucosa with lanthanum phosphate deposition

Background and study aims  A 78-year-old man with Helicobacter pylori infection had been undergoing hemodialysis for chronic renal failure and receiving lanthanum carbonate preparations for 3 years. Endoscopy revealed fine white granular discoloration throughout the stomach, a moderately reddish depression on the lesser curvature of the gastric angle, and white granular discoloration in the surrounding area. A magnified image using narrow-band imaging showed that the depressed part had irregular vascular and pit structures. We established a diagnosis of intramucosal gastric cancer and performed endoscopic submucosal dissection. Histopathological examination revealed a well-differentiated adenocarcinoma that was confined to the mucosa of the depressed area. Moreover, using an electron probe microanalyzer-equipped electron microscope, we found that the degree of lanthanum deposition was lower in the tumor region than in the non-tumor region. Thus, the current case can help in understanding the relationship between lanthanum deposition and early-stage gastric cancer. Because gastric cancers can occur in lanthanum deposit-containing mucosa, esophagogastroduodenoscopy should be used carefully after understanding the characteristics of early- stage gastric cancer in such cases.

Lanthanum-Induced Mucosal Alterations in the Stomach (Lanthanum Gastropathy): a Comparative Study Using an Animal Model

Lanthanum (La) carbonate (LC) is one of the most potent phosphate binders that prevents the elevation of serum phosphate levels in patients with end-stage renal diseases undergoing dialysis. LC binds strongly to dietary phosphate and forms insoluble complexes that pass through the gastrointestinal tract. La deposition in patients treated with LC is a recently documented finding particularly observed in gastric mucosa. We herein describe the detailed gastric mucosal lesions in 45 LC-treated patients and address the potential underlying pathologic mechanism using oral LC administration in rats. Microscopically, La deposition, as shown by subepithelial collections of plump eosinophilic histiocytes or small foreign body granulomas containing coarse granular or amorphous inclusion bodies, was found in the gastric mucosa of 44 (97.8%) of the 45 dialysis patients in the study cohort, which was most frequently associated with foveolar hyperplasia (37.8%). Using oral administration of rats with 1000 mg/day LC for 2 or more weeks, La deposition was consistently detectable in the gastric mucosa but not in other organs examined. In addition, various histologic alterations such as glandular atrophy, stromal fibrosis, proliferation of mucous neck cells, intestinal metaplasia, squamous cell papilloma, erosion, and ulcer were demonstrated in the rat model. Thus, orally administered LC can induce mucosal injury, designated here as La gastropathy, which may alter the local environment and result in La deposition in the gastric mucosa, thereby potentially inducing abnormal cell proliferation or neoplastic lesions.

Lanthanum deposition corresponds to white lesions in the stomach

OBJECTIVE

Although lanthanum deposition in the stomach has been most frequently reported to occur as white lesions, no study has investigated whether the white lesions observed during esophagogastroduodenoscopy are truly lanthanum-related. Here, we retrospectively investigated the amount of lanthanum in endoscopic biopsy specimens.

METHODS

We reviewed four patients showing gastric white spots or annular whitish mucosa in the gastric white lesions (Bw) and peripheral mucosa where the white substance was not endoscopically observed (Bp) during biopsy. We also reviewed three patients with diffuse whitish mucosa and three patients with no whitish lesions. We performed scanning electron microscopy and energy dispersive X-ray spectrometry to quantify the lanthanum elements (wt%) in the biopsy specimens.

RESULTS

The amount of lanthanum in the Bw ranged from 0.15-0.31 wt%, whereas that of Bp was 0.00-0.13 wt%. The difference was statistically significant (P < 0.05). The amount of lanthanum in the Bw, endoscopically presented with white spots or annular whitish mucosa, was significantly higher than that of no whitish lesions (0.05-0.14 wt%, P < 0.05). The amount of lanthanum was also higher in the diffuse whitish mucosa (0.21-0.23 wt%) compared with no whitish lesions (P < 0.01).

CONCLUSIONS

This study is the first to reveal that pathological lanthanum deposition corresponds to the endoscopically observed white lesions in the gastric mucosa. Therefore, during esophagogastroduodenoscopy, physicians should pay attention to possible presence of white lesions in patients treated with oral lanthanum carbonate to ensure prompt identification of associated issues.

Lanthanum Deposition in the Stomach in the Absence of Helicobacter pylori Infection

In this case report, we describe two patients who showed a diffusely whitish mucosa in the posterior wall and the lesser curvature of the gastric body. The patients were serologically- and histopathologically-negative for Helicobacter pylori. Random biopsy specimens from the stomach revealed no regenerative changes, intestinal metaplasia, and/or foveolar hyperplasia in either of the patients. Although lanthanum deposition in the gastric mucosa has been reported to occur in close association with H. pylori-associated gastritis, our patients tested negative for H. pylori. These cases suggest that lanthanum deposition presents as whitish lesions in the gastric body in H. pylori-negative patients.

Pharmacotherapy in chronic kidney disease hyperphosphatemia – effects on vascular calcification and bone health

Hyperphosphatemia (HP) in patients with chronic kidney disease (CKD) leads to complications such as renal osteodistrophy, cardiovascular calcification and hemodynamic abnormalities, all of them having a serious impact on the survival rate and quality of life. Also, HP is a key pathogenic factor in the development of secondary hyperparathyroidism (SHPT) in CKD. Having in regard the significance of controlling serum phosphorus levels (Pi), in this paper, the needs and obstacles to successful pharmacological management of HP in CKD are presented, with an overview of major classes of phosphate binders (PBs) and other drugs affecting Pi level, such as active vitamin D sterols and calcimimetics (CMs). In addition, their effects on progression of cardiovascular calcification and bone health are elaborated. In this regard, a PubMed search was carried out to capture all abstracts and articles relevant to the topic of CKD, HP and mineral metabolism, bone disorders and vascular/valvular calcification (VC), published from January 2007 to August 2017. The search was limited to English language, with the search terms including drug name AND hyperphosphatemia or cardiovascular calcification or bone disorder. Comparative studies, clinical studies/trials and meta-analyses related to different classes/representatives of PBs, vitamin D analogues and CMs were reviewed and research data related to their efficacy and safety compared. Keywords: chronic kidney disease, hyperphosphatemia, phosphate binders, active vitamin D sterols, calcimimetics, bone disorders, cardiovascular calcification

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

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.

Correlation of lanthanum dosage with lanthanum deposition in the gastroduodenal mucosa of dialysis patients

Lanthanum (La) deposition has been observed in gastrointestinal mucosa of dialysis patients treated with La carbonate to treat hyperphosphatemia in the 6 years since its authorization in Japan. We investigated gastrointestinal biopsies from 112 dialysis patients, and found 15 cases of histiocytic aggregation with crystalloids and one case of duodenitis with histiocyte aggregation without crystalloids in the 30 patients treated with La carbonate. No histiocytic lesions were observed in the 82 patients without La carbonate administration. So far in total 70 cases of La deposition in the alimentary tract have been reported, including our 16 cases. Neither clinical nor histological findings other than histiocytic aggregation were specific in the patients with La deposition. We also compared the groups with and without La deposition, revealing that the daily and total doses of La carbonate showed statistically significant correlations with La deposition. However the causality with their histologic features, e.g. intestinal metaplasia and degree of inflammation, were inconclusive between the two groups. Although no critical symptoms have been reported, it is necessary to accumulate more cases to clarify the mechanism of La deposition, because dialysis patients must take phosphate buffers for a long period.

A Combined Deposition of Lanthanum and β2-Microglobulin-Related Amyloid in the Gastroduodenal Mucosa of Hemodialysis-Dependent Patients: An Immunohistochemical, Electron Microscopic, and Energy Dispersive X-Ray Spectrometric Analysis

Lanthanum carbonate (LC) is a new type of phosphate adsorbent used to treat patients with hyperphosphatemia caused by chronic kidney diseases. Recent studies have pointed out that lanthanum deposition can be found in the cytoplasm of histiocytes in the gastroduodenal mucosa of these patients. On the other hand, it is well known that patients on long-term hemodialysis can develop deposition of β2-microglobulin-related amyloid (Aβ2M) mainly around joints. However, involvement of the gastrointestinal tract by hemodialysis-associated amyloidosis has been thought to be rare, and therefore only Aβ2M, if any, has been reported to accumulate in the vascular walls of the submucosa and muscularis propria. Thus, in contrast to AA amyloid, biopsy from gastrointestinal mucosa has long been considered to have little significance in detecting amyloid. We present unusual histologic findings on biopsy specimens taken from the gastroduodenal mucosa of 7 hemodialysis-dependent patients taking LC for more than a year. These findings were due to a combined deposition of lanthanum and β2-microglobulin-related amyloid in the cytoplasm of histiocytes. The deposition of amyloid was confirmed by conventional histochemistry, immunohistochemistry, and transmission electron microscopy, and that of lanthanum by transmission electron microscopy and scanning electron microscopy/energy dispersive X-ray spectrometry. This is the first report of such a peculiar combined deposition of lanthanum and amyloid in the gastroduodenal mucosa of hemodialysis patients. Although the exact mechanism of combination and pathogenesis is unclear, we believe that histologic examination of the gastrointestinal mucosa should be considered in the careful follow-up and observation of hemodialysis patients taking LC.

Lanthanum deposition from oral lanthanum carbonate in the upper gastrointestinal tract

AIMS

Lanthanum carbonate is used as an alternative to calcium-based phosphate binders to manage hyperphosphataemia in patients with renal failure. The deposition of lanthanum within gastroduodenal mucosa of patients treated with the medication has been described, but given the relative novelty of this entity, the histiocytic deposits in the gastroduodenal mucosa can be confused with a variety of other processes, including infections and other drug-induced forms of injury.

METHODS AND RESULTS

We describe five cases of lanthanum phosphate deposition in upper gastrointestinal (GI) tract biopsies. Three cases were confirmed with scanning electron microscopy and energy dispersive X-ray analysis, including one unique patient, status post-renal transplant for polycystic kidney disease, who had last taken lanthanum 7 years prior to biopsy.

CONCLUSION

Lanthanum deposition in the upper GI tract is a mimic of other drug-related forms of GI injury, including iron pill-related gastropathy. The key to making this diagnosis is a thorough drug history and awareness of the histological features.

Gastric mucosal status susceptible to lanthanum deposition in patients treated with dialysis and lanthanum carbonate

Lanthanum carbonate is a popular chemical which is administered for patients with end-stage kidney disease to reduce the absorption of phosphate, and lanthanum deposition in the gastroduodenal mucosa has recently been reported. The aim of this study was to assess whether any histologic changes of the gastric mucosa are related to the deposition of lanthanum. Twenty-four patients who revealed the histology of lanthanum deposition on gastroduodenal biopsy between 2011 and 2014 were included in the study, and their clinical records and gastroduodenal biopsies obtained from 2011 to 2015 were reviewed, adding the review of gastroduodenal biopsies before 2011 if possible. Analysis of the deposited materials by scanning electron microscopy-energy dispersive x-ray spectroscopy was performed for a representative gastric biopsy. All patients were diagnosed as having renal insufficiency due to chronic kidney disease and treated with dialysis for more than 5 years, with confirmation of lanthanum carbonate use for 22 patients. Of 121 gastric biopsies and 10 duodenal ones between 2011 and 2015, 86 gastric biopsies (71.1%) and 3 duodenal biopsies (30%), respectively, revealed histology consistent with lanthanum deposition, which was confirmed by scanning electron microscopy-energy dispersive x-ray spectroscopy analysis for a representative case. The deposition tended to occur in the gastric mucosa with regenerative change, intestinal metaplasia, or foveolar hyperplasia (P<.05). Such mucosal changes were observed in about half of the gastric biopsy samples obtained prior to 2010, in which no lanthanum deposition was identified irrespective of the gastric mucosal status. Although direct association between lanthanum deposition and clinical symptoms is not clear, the evaluation of the gastric mucosal status (prior to administration) seems to be important to predict lanthanum deposition when lanthanum carbonate is administered for patients with chronic kidney disease treated with dialysis.

Lanthanum deposition in the gastrointestinal mucosa and regional lymph nodes in dialysis patients: Analysis of surgically excised specimens and review of the literature

Lanthanum carbonate (LC) is one of the most potent phosphate binders currently used to reduce serum phosphate levels in dialysis patients with end-stage renal disease (ESRD). LC forms insoluble complexes with dietary phosphate that pass through the gastrointestinal (GI) tract with little absorption. GI lesions due to lanthanum deposition in biopsy specimens or those in endoscopic submucosal dissection (ESD) in dialysis patients have been recently identified. Here, we describe more detailed histopathological findings in the gastroduodenal mucosa and regional lymph nodes in three patients with gastric cancer. Three patients with ESRD, two elderly women and one man, underwent dialysis and were treated with LC for 3-36 months. The patients underwent laparoscopic distal gastrectomy and lymph node dissection due to gastric cancer. Many subepithelial histiocyte aggregates or small foreign body granulomas, which contained gray or brown pigments or crystal-like structures, were mostly present in non-neoplastic areas of the upper GI. Lanthanum accumulation was noted in the duodenal mucosa and the antral and body mucosae of the gastric lesser curvature. Lanthanum was also deposited in the regional lymph nodes of the three patients. Electron microscopy with energy dispersive X-ray spectroscopy confirmed lanthanum and phosphorus deposits in histiocytes. Long-term prognosis of patients and the excretion or the metabolic pathway of accumulated lanthanum remain unclear.