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

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CONTEXT.—

With the increasing development and use of iatrogenic agents, pathologists are encountering more novel foreign materials in retrieved gastrointestinal specimens. These colorful and unusual-appearing foreign materials can pose a diagnostic dilemma to those unaware of their morphology, especially if the relevant clinical history is lacking.

OBJECTIVE.—

To discuss the histopathologic features, clinical scenarios and significance, and differential diagnosis of relatively recently described, yet quickly expanding, family of iatrogenic agents that can present as foreign materials in gastrointestinal specimens-pharmaceutical fillers (crospovidone and microcrystalline cellulose), submucosal lifting agents (Eleview and ORISE), lanthanum carbonate, hydrophilic polymers, OsmoPrep, yttrium 90 microspheres (SIR-Sphere and TheraSphere), and resins (sodium polystyrene sulfonate, sevelamer, and bile acid sequestrants).

DATA SOURCES.—

We collate the findings of published literature, including recently published research papers, and authors' personal experiences from clinical sign-out and consult cases.

CONCLUSIONS.—

Correct identification of these iatrogenic agents is important because the presence of some novel agents can explain the histopathologic findings seen in the background specimen, and specific novel agents can serve as diagnostic clues to prompt the pathologist to consider other important and related diagnoses. Awareness of even biologically inert agents is important for accurate diagnosis and to avoid unnecessary and expensive diagnostic studies.

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.

Investigation of the clinical significance and pathological features of lanthanum deposition in the gastric mucosa

Background

There are often specific endoscopic findings caused by deposition of lanthanum (La) in the gastric mucosa of patients taking lanthanum carbonate (LaC), a novel phosphate binder for patients on hemodialysis. We conducted a retrospective study to investigate the clinical significance of La deposition in the gastric mucosa, and the association between endoscopic features and histologic findings in the same population.

Methods

We compared background factors in patients taking LaC with and without La deposition in their gastroscopic biopsy specimen. We also investigated the relationship between gastric endoscopic biopsy specimens with La deposition and the concurrent endoscopic images.

Results

There was a significant difference in the total dose of LaC between the La-positive and La-negative groups (990 g [180–3150 g] vs. 480 g [225–1328 g]; p = 0.013). In 27 biopsy specimens with specific whitish mucosa, 10 showed mild histiocytic infiltration and 17 showed severe infiltration. In contrast, among 24 specimens with non-whitish mucosa, 5 showed no histiocytic infiltration, 10 showed mild infiltration, and 9 showed severe infiltration. There was a significant relationship between endoscopic features and the degree of histiocytic infiltration (p = 0.026).

Conclusions

We demonstrated that La deposition in the gastric mucosa depended on the total dose of LaC and was not affected by background factors. The specific endoscopic features of La deposition are associated with the infiltration of histiocytes, which represents the body’s normal response to foreign bodies.

Trial registry The protocol was registered in the University Hospital Medical Information Network Clinical Trial Registry (UMIN000038929, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000044393).

Quantitative Visualization of Lanthanum Accumulation in Lanthanum Carbonate-Administered Human Stomach Tissues Using Mass Spectrometry Imaging

Platinum, a transition metal that is widely used in anti-cancer agents, also results in the development of nephropathy due to severe adverse reactions caused by platinum-induced nephrotoxicity. Reports on imaging with metals other than platinum remain are limited, even in preclinical studies. Furthermore, most of these are case reports, and the relationship between the distribution of the metal and clinical observations in human samples is not well understood. Here we report on visualizing lanthanum (¹³⁹La), a component of Fosrenol, which is usually used for the treatment of hyperphosphatemia. Gastric inflammation, also known as hemorrhagic gastritis, is the main adverse event caused by Fosrenol. To conduct this study, ¹³⁹La was visualized in gastric biopsy samples obtained from a patient using quantitative laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). We also compared the distribution of ¹³⁹La in tissue and histochemical results. The areas where ¹³⁹La accumulated corresponded to the macrophage-positive areas observed in immunohistochemistry studies using an anti-CD68 antibody. In contrast, we observed a debris-like crystal morphology in hematoxylin and eosin staining tissues. The debris was also associated with ¹³⁹La accumulation. The abnormal accumulation of ¹³⁹La crystals caused the observed inflammation. This phenomenon was previously characterized, but this is the first report in which ¹³⁹La distribution and histochemical results are compared using LA-ICP-MS.

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.

Review of Drug-induced Injury in Mucosal Biopsies From the Tubular Gastrointestinal Tract

The use of prescription and over-the-counter medications is on the rise in the US population, especially among those aged 65 and over, with over 46% of the population taking at least 1 prescription medication. Given the frequency of medication use, and that the majority of these medications are taken orally, it has become increasingly relevant for pathologist examining endoscopically obtained gastrointestinal tract mucosal biopsies to consider and recognize patterns of mucosal injury associated with various drugs. Reports on injuries associated with certain classes of drugs can be scattered among different sources, making a comprehensive view of various injury patterns and the drugs known to cause them difficult to obtain. Herein, we provide a comprehensive overview of the drugs known to cause mucosal injuries in the tubular gastrointestinal tract organized by the organ involved and the prominent pattern of injury.

Lanthanum phosphate binder-induced iron deficiency anaemia

Lanthanum carbonate is a phosphate binder that is used to reduce serum phosphate levels in patients with end-stage renal disease (ESRD). Lanthanum forms insoluble lanthanum phosphate complexes that are supposed to pass through the gastrointestinal (GI) tract unabsorbed. Phosphate binders have been reported to deposit in the GI tract and can cause mucosal injury. There are few case reports of GI bleeding associated with phosphate binder deposits. This case report presents a patient with iron deficiency anaemia secondary to biopsy-proven lanthanum deposits in the upper GI tract. There were no overt signs of active GI bleeding. Patient's anaemia improved with discontinuation of the phosphate binder. Lanthanum could be a hidden cause of resistant anaemia among patients with ESRD through asymptomatic GI blood loss.

M2-polarized macrophages relate the clearance of gastric lanthanum deposition

Previous reports have suggested that mucosal barrier failure allows lanthanum to stray into the lamina propria, and macrophages play an important role for the clearance. However, there is no report to analyze the polarity of phagocytizing macrophages. We suggested that M2 macrophage potentially played a major role in the clearance of lanthanum.

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