Iron deposition in gastric black spots: Clinicopathological insights and NanoSuit-correlative light and electron microscopy analysis

Objectives

Black spots (BSs) are lentiginous findings observed in the gastric body and fundus during upper gastrointestinal endoscopy and are predominantly seen in patients undergoing Helicobacter pylori eradication treatment. However, the detailed patient background and exact composition are poorly understood. This study aims to clarify the clinicopathological features of BSs, examine patient demographics, and use the NanoSuit-correlative light and electron microscopy (CLEM) method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy for elemental analysis.

Methods

Patients who underwent upper gastrointestinal endoscopy between 2017 and 2022 were included. Data on age, medications, blood tests, and H. pylori infection status were retrospectively gathered from medical records. Univariate analysis was conducted to examine BS presence, with results then used in a multivariate model to identify associated risk factors. Additionally, pathological specimens from patients with BSs were analyzed for elemental composition using the NanoSuit-CLEM method combined with scanning electronmicroscopy-energy dispersive X-ray spectroscopy.

Results

An analysis of 6778 cases identified risk factors for BSs, including older age and using proton pump inhibitors, statins, corticosteroids, and antithrombotic drugs. Endoscopically, BSs correlated with higher gastric atrophy and lower active H. pylori infection. Iron deposition at BS sites was specifically identified using NanoSuit-CLEM.

Conclusions

BSs on gastrointestinal endoscopy may indicate an absence of active H. pylori inflammation. The discovery of iron deposition within BSs using the NanoSuit-CLEM method has offered new insights into the possible causative factors and advances our understanding of the etiology of BSs, bringing us closer to unraveling the underlying mechanisms of their formation.

Endoscopic findings and outcomes of gastric mucosal changes relating to potassium-competitive acid blocker and proton pump inhibitor therapy

Gastric mucosal changes associated with long-term potassium-competitive acid blocker and proton pump inhibitor (PPI) therapy may raise concern. In contrast to that for PPIs, the evidence concerning the safety of long-term potassium-competitive acid blocker use is scant. Vonoprazan (VPZ) is a representative potassium-competitive acid blocker released in Japan in 2015. In order to shed some comparative light regarding the outcomes of gastric mucosal lesions associated with a long-term acid blockade, we have reviewed six representative gastric mucosal lesions: fundic gland polyps, gastric hyperplastic polyps, multiple white and flat elevated lesions, cobblestone-like gastric mucosal changes, gastric black spots, and stardust gastric mucosal changes. For these mucosal lesions, we have evaluated the association with the type of acid blockade, patient gender, Helicobacter pylori infection status, the degree of gastric atrophy, and serum gastrin levels. There is no concrete evidence to support a significant relationship between VPZ/PPI use and the development of neuroendocrine tumors. Current data also shows that the risk of gastric mucosal changes is similar for long-term VPZ and PPI use. Serum hypergastrinemia is not correlated with the development of some gastric mucosal lesions. Therefore, serum gastrin level is unhelpful for risk estimation and for decision-making relating to the cessation of these drugs in routine clinical practice. Given the confounding potential neoplastic risk relating to H. pylori infection, this should be eradicated before VPZ/PPI therapy is commenced. The evidence to date does not support the cessation of clinically appropriate VPZ/PPI therapy solely because of the presence of these associated gastric mucosal lesions.

White Spot, a Novel Endoscopic Finding, May Be Associated with Acid-Suppressing Agents and Hypergastrinemia

White globe appearance (WGA) is defined as a microendoscopic white lesion with a globular shape underlying the gastric epithelium and is considered a marker of gastric cancer. We recently reported that endoscopically visualized white spot (WS) corresponding to WGA appeared on the nonatrophic mucosa of patients with acid-suppressing agents (A-SA) use. We evaluated patients undergoing routine esophagogastroduodenoscopy and divided the patients into an A-SA group (n = 112) and a control group (n = 158). We compared the presence of WS in both groups. We also compared WS-positive- (n = 31) and -negative (n = 43) groups within the A-SA group regarding these patients’ backgrounds and serum gastrin concentrations. Comparing the A-SA group with controls, the prevalence of WS was significantly higher (31/112 vs. 2/158; p < 0.001). The number of patients with high serum gastrin concentrations was significantly higher in the WS-positive group (18/31) vs. the WS-negative group (5/43) (p < 0.001). Within the A-SA group, the prevalence of WS was also significantly higher in patients taking potassium-competitive acid blockers vs. proton-pump inhibitors (21/31 vs. 10/31, p < 0.001). The WS-positive group had a significantly greater percentage of patients, with a high serum gastrin level (p < 0.001). WS may be associated with hypergastrinemia and potassium-competitive acid blockers.

Marked reduction in the number of white globe appearance lesions in the noncancerous stomach after exchanging vonoprazan for esomeprazole treatment: a follow-up case report

Recently, an association has been suggested between development of white globe appearance lesions in the noncancerous stomach and treatment with a potassium-competitive acid blocker or a proton pump inhibitor. We previously reported two cases with development of white globe appearance lesions after vonoprazan treatment, suggesting a similar association. Here, we present the follow-up report of one of those two cases, concerning a 68-year-old woman who developed multiple white globe appearance lesions 1 year after starting vonoprazan treatment for severe gastroesophageal reflux disease leading to esophageal stricture. The patient refused to continue vonoprazan treatment after the lesions developed, and esomeprazole was initiated instead. Three months later, most of the white globe appearance lesions had disappeared, without worsening of her gastroesophageal reflux disease. Histologically, mucosal structural changes induced by vonoprazan, such as parietal cell protrusion with oxyntic gland dilatation, remained unchanged, whereas the gastric glands became less packed and a small calcification in the concentrated eosinophilic material was observed in a remaining white globe appearance cyst after esomeprazole treatment. Here, we discuss possible pathogenic mechanisms of these dramatic gastric mucosal changes observed in the present case, based on our endoscopic and histological findings.

Ultrastructural intestinal mucosa change after prolonged inhibition of gastric acid secretion by omeprazole in male rats

Omeprazole is a potent inhibitor of gastric acid secretion. It was reported that omeprazole induced dramatic gastric mucosa morphologic changes from the resting state to the stimulated state. However, the effect of omeprazole administration on the ultrastructure and absorptive function of small intestines was largely unknown. Here, male Sprague-Dawley rats were daily treated with a single dose of omeprazole for 12 or 24 weeks. Ultrastructure intestinal mucosal change in duodenum, jejunum, and ileum was observed. We also determined small intestine inflammation, using intraepithelial lymphocytes activation. Finally, magnesium levels were measured in plasma, urine, feces, muscle, and bone to determine systemic magnesium balance. Omeprazole-treated rats had significantly decreased the width of tight junction, villous length, and absorptive area of duodenum, jejunum, and ileum compared to control rats. The small intestine of the omeprazole-treated group showed significantly higher intraepithelial lymphocytes activation levels compared with the control group. Lower secretory granules of Paneth cells at the base of the crypts were showed in omeprazole-treated rats. They also had significantly lower plasma, urinary, bone, and muscle Mg2+ contents indicating hypomagnesemia with systemic magnesium deficiency. In conclusion, prolonged omeprazole treatment-induced small intestinal inflammation and villous atrophy, which led to decrease small intestinal magnesium absorption in the condition of proton pump inhibitor-induced hypomagnesemia.

Development of white globe appearance lesions in the noncancerous stomach after vonoprazan administration: a report of two cases with a literature review

White globe appearance has recently been identified as a novel endoscopic marker useful in the diagnosis of early gastric cancer. Recently, this lesion has also been reported in the noncancerous stomach, including cases with autoimmune atrophic gastritis, although the clinical significance remains unclear. We present the details of a 68-year-old woman who began vonoprazan therapy for severe gastroesophageal reflux disease causing esophageal stricture. On follow-up endoscopy 1 year after beginning vonoprazan, multiple white globe appearance lesions developed in all sections of her stomach, except for the antrum. We also detected lesions during a yearly follow-up in the noncancerous stomach of a 70-year-old man who had received vonoprazan for 3 years. Lesions in both cases constituted cystic gland dilatations containing eosinophilic material. There was no evidence of accompanying autoimmune atrophic gastritis in either patient. This report is the first to our knowledge describing newly developed white globe appearance lesions in the noncancerous stomach during follow-up in two cases who received vonoprazan. Our findings suggest that these lesions in the noncancerous stomach might be associated with vonoprazan treatment. We investigated the two cases endoscopically and histologically, and we report our findings with a literature review.

Gastric mucosal cracked and cobblestone-like changes resulting from proton pump inhibitor use

BACKGROUND AND AIM

Use of proton pump inhibitors (PPI) is histologically associated with oxyntic gland dilatations. Two interesting mucosal changes are often detected endoscopically in patients who use PPI: gastric cracked mucosa (GCM) and gastric cobblestone-like mucosa (GCSM). The aim of the present study was to clarify the relationship between PPI use and these mucosal changes.

METHODS

This was a single-center observational study. All successive subjects who underwent a routine esophagogastroduodenoscopy (EGD) between August and November 2014 in Hokkaido University Hospital were enrolled. Endoscopists carried out the assessment blinded to the use of PPI and checked for GCSM and GCM using original diagnostic criteria for GCM and GCSM. Subjects were divided into two groups: those who used PPI (PPI group) and those who did not (control group). Endoscopic findings and backgrounds were compared between the two groups.

RESULTS

A total of 538 patients were analyzed (control group: 374 patients, men/women: 204/170, median age: 65.2 years; PPI group: 164 patients, men/women: 89/75, median age: 67.1 years). GCM was detected in 54 (10.0%) subjects, and GCSM was detected in 18 (3.3%) subjects. There was a significant difference in the prevalence rate of GCM between the control group (14/374, 3.7%) and the PPI group (40/164, 24.4%) (P < 0.01). GCSM was significantly more prevalent in the PPI group (15/164, 9.1%) than in the control group (3/374, 0.8%) (P < 0.01).

CONCLUSION

Novel GCM and GCSM endoscopic findings in the corpus area seem to be strongly associated with PPI use.

Twelve-year natural history of a gastric adenocarcinoma of fundic gland type

A 77-year-old woman underwent an upper gastrointestinal (UGI) endoscopy screening examination, and a 10-mm reddish, submucosal tumor-like lesion was found on the posterior wall of the fornix. Biopsy was performed, but there was no evidence of malignancy, so annual follow-up by UGI endoscopy was decided upon. After 12 years, examination of another biopsy specimen revealed an adenocarcinoma of the fundic gland type. There had been no significant change in the size or shape of the lesion over the long follow-up period. Endoscopic submucosal dissection (ESD) was performed, and en bloc resection was achieved. Histopathologically, the tumor appeared as a flat elevated lesion measuring 11 × 10 mm. It was composed of irregularly shaped glands and invaded the submucosa up to 300 µm. Immunohistochemical examination involving specific antibodies to pepsinogen I, MIST-1, MUC6, and H⁺/K⁺-ATPase confirmed the fundic gland differentiation of the irregularly shaped glands together with a very low Ki-67 labeling index. Thus, gastric adenocarcinoma of the fundic gland type (GAFG) was diagnosed. Four years have passed since the ESD, and there has been no recurrence. To the best of our knowledge, this is the first report of the long-term natural history of GAFG. Over the 12 years, no morphologic changes were observed; the tumor remained within the submucosal layer. Our observations in this case strengthen the notion that GAFG is a specific type of gastric adenocarcinoma of low-grade malignancy.