Gastric enterochromaffin-like cell changes in multiple endocrine neoplasia type 1

BACKGROUND

Gastric enterochromaffin-like cell (ECL) tumours can occur in patients with multiple endocrine neoplasia type 1 (MEN1), especially in those affected by Zollinger Ellison syndrome (ZES). Since the prevalence of ECL lesions is not well defined yet, the present study evaluated the presence and extent of ECL lesions in MEN1 patients with and without ZES.

METHODS

Multiple endocrine neoplasia type 1 patients being part of a regular screening program (2014-2018) underwent gastroduodenoscopies with biopsies of the stomach and determination of serum gastrin and chromogranin A levels. Haematoxylin- and immunostaining with chromogranin A, gastrin and VMAT I and II (vesicular monoamine transporter I and II) of the biopsies were performed.

RESULTS

Thirty-eight MEN1 patients, of whom 16 (42%) were diagnosed and treated earlier for ZES, were analysed. In ten of 16 (62.5%) ZES patients, a locally scattered, mixed image of diffuse, linear and micronodular mild hyperplasia was present. In addition, two of these patients (13%) showed small (max 1.5 mm in size) intramucosal ECL tumours. Neither ECL changes, nor tumours were found in MEN1 patients without ZES (n = 22). In MEN1/ZES patients, the median serum gastrin level was significantly elevated compared to MEN1 patients without ZES (206 pg/ml vs. 30.5 pg/ml, p < .001). A subgroup analysis of the serum gastrin and chromogranin A levels of MEN1/ZES patients with or without ECL hyperplasia did not show significant differences (gastrin level: p = .302, chromogranin A: p = .464).

CONCLUSION

Enterochromaffin-like cell hyperplasia and gastric carcinoids occur only in MEN1 patients with ZES, but less frequently than reported.

Spontaneous ECL cell carcinomas in cotton rats: natural course and prevention by a gastrin receptor antagonist

In our inbred strain of cotton rats (Sigmodon hispidus) 50% of the females develop spontaneous ECL cell-derived tumors in the acid-producing part of the stomach due to hypergastrinemia secondary to gastric hypoacidity. Although the mechanism behind the hypoacidity is unknown, the female cotton rat is an excellent model for studying ECL cell-related tumorigenesis. In this study we wanted to explore the malignancy potential of these tumors and the ability of a gastrin receptor antagonist (YF476) to prevent their development. First, nine hypergastrinemic female cotton rats (10 months of age) were diagnosed by laparotomy as having gastric tumors. They were killed 6 months later. Second, 18 female cotton rats (2 months of age) were dosed monthly for 6 months with YF476 (500 micro mol/kg body wt) by s.c. injection, while 21 age-matched animals received vehicle. Samples from each stomach were collected for histology, immunohistochemistry and northern blot analysis. The gastric tumors harbored cells with immunohistochemical features of ECL cells. The tumors were found at times to invade and penetrate the stomach wall and to metastasize to perigastric sites. ECL-derived tumor cells were discovered in peritoneal fluid. At death only 1 out of 18 animals given YF476 displayed carcinomas (invasive growth), compared with 7 out of 21 in the vehicle dosed control group (P = 0.048). The spontaneous gastric tumors in cotton rats derived from ECL cells. The tumors were able to penetrate the stomach wall and to metastasize by intracavital seeding. Gastrin receptor blockade lowered the incidence of such tumors. We propose that the tumors are ECL cell carcinomas and that gastrin is the driving force behind the transformation from normal to malignant ECL cells.

[Fundic endocrine tumors and atrophic gastritis: the value of antrectomy]

We report two cases of fundic endocrine tumors associated with fundic atrophic gastritis-related hypergastrinemia and treated by antrectomy. About twenty infracentimetric tumors were observed in each patient and restrictively involved fundic mucosa. Antrectomy induced normalization of gastrinemia and the disappearance of fundic tumors, as soon as the 4(th) and 7(th) month. No recurrence was observed during the 5-year and 18-month follow-up time, respectively. We therefore consider that antrectomy may be regarded as a useful alternative treatment in the management of atrophic gastritis-related fundic endocrine tumors.

Are current textbooks good enough for physiology education? For example, the ECL cells are missing

Current textbooks are believed to provide an updated knowledge. Medical students usually read the textbooks but not the literature that contain the original research articles and reviews. Here, we examined the gap between the current textbooks and literature with the enterochromaffin-like (ECL) cells as an example. A total of 70 textbooks that were published for medical education during the last 10 yr was examined. The literature has been searched mainly from the Internet. We found that most textbooks (59 of 70) fail to mention the ECL cells. Due to the lack of information on the ECL cells, the mechanisms behind gastric acid secretion are described variously from book to book. However, up to the year 2000, 574 research articles and reviews have been published on the various aspects of the ECL cells. The role of the ECL cells in the regulation of the acid secretion has been well demonstrated for more than 20 years. The fact that the textbooks are out of date cannot be explained by the time required to write and publish them. Therefore, we question whether or not the current textbooks are good enough for physiology education and suggest both teachers and students read not only the textbooks, but also utilize the other sources such as the Internet to find and fill the gaps between the textbooks and literature. This is one of the approaches of problem-based learning.

Changes in gastric mucosa and luminal environment during acid-suppressive therapy: a review in depth

Acid-suppressive therapy and subsequent changes in gastric mucosa and luminal environment rank highly amongst the investigated issues in gastroenterology over the past two to three decades. Herewith, we present an overview of these intragastric changes, particularly during long-term administration of acid-suppresive medication and concurrent infection with Helicobacter pylori. Current evidence indicates that: i) Long-term acid suppression facilitates the development of fundic ECL cell hyperplasia, especially in the presence of Helicobacter pylori. No neoplastic changes directly attributable to acid suppression have so far been demonstrated in humans. ii) Acid-suppressive therapy increases the risk of enteric infections. iii) Acid-suppressive therapy does not alter fat and mineral bioavailability, but may decrease the absorption of protein-bound vitamin B12. iv) Acid suppression invariably results in intragastric overgrowth of non-Helicobacter pylori bacterial species. The concurrent infection with Helicobacter pylori may promote this bacterial overgrowth and the intragastric formation of N-nitrosamines. v) Acid-suppressive therapy alters the natural course of Helicobacter pylori gastritis, transforming the antral-predominant pattern into a body-predominant pattern, which in turn may progress to body gland atrophy. The pathophysiology of this phenomenon is currently under investigation. vi) In view of the potential adverse effects of acid suppression in the presence of Helicobacter pylori, the screen-and-treat strategy is advocated for Helicobacter pylori in subjects considered for long-term treatment.

First endoscopic-histologic follow-up in patients with body-predominant atrophic gastritis: when should it be done?

BACKGROUND

Body-predominant atrophic gastritis is considered a risk factor for gastric cancer and carcinoid. Timing of follow-up for patients with this disorder has not been defined. This study was undertaken to determine the optimal time for the first endoscopic/histologic follow-up in patients with body-predominant atrophic gastritis.

METHODS

Forty-two patients with body-predominant atrophic gastritis were randomly assigned to 1 of 2 follow-up intervals: group A (n = 22) at 24 months and group B (n = 20) at 48 months. At baseline and follow-up patients underwent gastroscopy at which biopsies were obtained from the antrum and body for histopathology and evaluation for enterochromaffin-like cells.

RESULTS

In group A patients, 2 antral hyperplastic polyps (9.1%) were present at baseline and 4 antral hyperplastic polyps (18.2%) were found at follow-up. In group B patients, baseline gastroscopy revealed 2 antral hyperplastic polyps (10%) and follow-up 2 antral hyperplastic polyps (10%) and 1 carcinoid tumor (5%) in the body. Atrophy and intestinal metaplasia scores in gastric body and antral mucosa in both groups did not change significantly between baseline and follow-up, except an increase in antral mucosa atrophy in group B patients (p = 0.02) was revealed.

CONCLUSIONS

The results of this study indicate that performing the first follow-up in patients with body-predominant atrophic gastritis need not be earlier than at 4 years after diagnosis. This interval is satisfactory for detection of potential neoplastic lesions.