Gastric adenocarcinoma of the fundic gland type: clinicopathological features of eight patients treated with endoscopic submucosal dissection

Abstract

Background Gastric adenocarcinoma of the fundic gland type (GA-FG) has been added to the 2019 edition of the World Health Organization’s list of digestive system-associated cancers. This lesion differentiates toward the fundic gland and mostly involves chief cell-predominant differentiation with low-grade cytology. Clinicians and pathologists are still unaware of this rare disease; consequently, some cases are incorrectly diagnosed. This study aimed to investigate the clinicopathological features of GA-FG using retrospective analyses of endoscopic and pathological findings. Materials and methods Samples were collected from patients diagnosed with GA-FG. The clinical courses of all patients were monitored prospectively and reviewed retrospectively. Available clinical information, endoscopic features, pathological appearance, and follow-up data were assessed. Immunohistochemistry [mucin (MUC) 2, MUC5, MUC6, P53, CDX2, Ki67, SYN, CD56, CGA, β-catenin, and pepsinogen-I] was examined using Envision two-step method. Results Eight cases of endoscopic submucosal dissection (ESD) were obtained from our institution. Patient age ranged from 48 to 80 years (mean, 65 years). Some patients were on acid-suppressing medication. Most lesions were located in the upper third (n = 7) and one was in the middle third of the stomach. Six lesions were of the superficial flat type, whereas two were of the superficial elevated type. Narrow-band imaging using magnifying endoscopy showed irregular microvascular patterns (MVPs) in four cases and regular MVPs in the remaining cases. All lesions were primarily solitary and ~ 6 mm in diameter (largest, 12 mm). The main body of the tumors were localized in the mucosal layer, of which six cases invade into the submucosal layer. Well-formed glands of chief cells were predominant. Tumor cells were positive for pepsinogen-I, MUC6, SYN, and CD56. Lymphatic and vascular infiltration and metastatic and recurrent disease were not observed in any case. Conclusion GA-FG, a well-differentiated adenocarcinoma with mild atypia, can be completely removed using ESD, with a favorable prognosis in patients.

Gastric adenocarcinoma of the fundic gland: A review of clinicopathological characteristics, treatment and prognosis

“…7 Most lesions are located in the middle and upper third of the stomach. 8 According to previous studies, the ratio of male to female patients with GA-FG is approximately 1.4 9 ; however, based on our analysis, the ratio is approximately 2.2. The GA-FG tumor volume is usually small, approximately 1 cm.…”

“…10 Most GA-FG patients do not have intestinal metaplasia, atrophic glands, or Helicobacter pylori (H. pylori) infection. 8,11 However, in our study, according to the available data, 19 of 67 GA-FG patients had H. pyloripositive infection, and 11 of 48 GA-FGnegative patients experienced H. pylori eradication therapy. Therefore, we think that the H. pylori infection should be given more attention as a factor in GA-FG pathogenesis.…”

“…Although most tumor lesions show submucosal invasion, lymphatic and vascular invasion is very rare. 7,8,15 According to our analysis, among 163 cases of GA-FG, 119 cases had submucosal infiltration (73%), and only two cases had subserosal infiltration. Although tumor submucosal involvement has been identified in most reports, thin wisps of muscularis mucosae with the absence of desmoplasia were identified throughout the lesions.…”

“…GA-FG is a welldifferentiated and low malignant potential tumor. Lymphatic and vascular invasion rarely occurs, 8,11,12 according to the Japanese classification of gastric carcinoma. Our current analysis shows that only 10 (6.3%) of 159 GA-FG cases with available relevant data had lymphatic invasion, and only 8 (5.0%) of 160 GA-FG cases had vascular invasion, which is similar to previous studies.…”

Long-term Observation of Gastric Adenocarcinoma of Fundic Gland Mucosa Type before and after Helicobacter pylori Eradication: a Case Report

“…The atypical cells of GA-FG are localized to the deep layer of the gastric mucosa, and the surface of GA-FG is covered by non-cancerous foveolar epithelium [ 2 ]. Reflecting the pathological features, the morphology typically presents as a submucosal tumor on conventional endoscopy, with a regular microsurface pattern without a demarcation line on magnifying endoscopy with narrow-band imaging (ME-NBI) [ 3 ]. GA-FG reportedly shows low-grade malignancy and slow growth [ 2 ].…”