Gastric adenocarcinoma of the fundic gland (chief cell-predominant type): A review of endoscopic and clinicopathological features

Abstract

Gastric adenocarcinoma of the fundic gland (chief cell-predominant type, GA-FG-CCP) is a rare variant of well-differentiated adenocarcinoma, and has been proposed to be a novel disease entity. GA-FG-CCP originates from the gastric mucosa of the fundic gland region without chronic gastritis or intestinal metaplasia. The majority of GA-FG-CCPs exhibit either a submucosal tumor-like superficial elevated shape or a flat shape on macroscopic examination. Narrow-band imaging with endoscopic magnification may reveal a regular or an irregular microvascular pattern, depending on the degree of tumor exposure to the mucosal surface. Pathological analysis of GA-FG-CCPs is characterized by a high frequency of submucosal invasion, rare occurrences of lymphatic and venous invasion, and low-grade malignancy. Detection of diffuse positivity for pepsinogen-I by immunohistochemistry is specific for GA-FG-CCP. Careful endoscopic examination and detailed pathological evaluation are essential for early and accurate diagnosis of GA-FG-CCP. Nearly all GA-FG-CCPs are treated by endoscopic resection due to their small tumor size and low risk of recurrence or metastasis.

Gastric adenocarcinoma of fundic gland type spreading to heterotopic gastric glands

“…According to Ueyama et al[ 10 ], endoscopic properties of GA-FG include no intestinal metaplasia or atrophic change in the surrounding mucosa, faded or whitish color, submucosal tumor shape with a soft appearance, and dilated vessels with branching architecture. Although the pathogenesis of GA-FG is unclear, GA-FG tends to arise from the normal gastric mucosa of the fundic gland region without atrophic change or intestinal metaplasia[ 2 ]. Therefore, H. pylori infection is not considered to contribute to the development of GA-FG, unlike for the regular histological type of gastric cancer.…”

“…Until recently, GA-FG has been recognized as cancer arising from gastric mucosa without atrophic change[ 2 ]. However, cases of GA-FG arising from gastric mucosa with atrophic change have now been reported[ 13 ].…”

“…Gastric adenocarcinoma of fundic gland type (GA-FG) is a new histological type of gastric cancer proposed by Ueyama et al[ 1 ] in 2010. As the concept of GA-FG has spread since then, new findings have been reported[ 2 ]. GA-FG tends to invade the submucosal layer while it is still small because it arises from the deep layer of the lamina propria mucosae[ 1 ].…”

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

“…Previously published reviews showed that the average tumor diameter was 7.5 mm. Approximately 80% of all tumors were less than 10 mm in diameter at the time of diagnosis 6 and the diameter of the largest reported tumor was 85 mm 8 . Our observations were consistent with those of previous reports (Table 1).…”

Gastric Adenocarcinoma of the Fundic Gland Type: Clinicopathological Features of Eight Patients Treated With Endoscopic Submucosal Dissection

“…The histological appearance of GA-FG is often that of a well-differentiated neoplasm, with a tumor-bearing resemblance to that of the fundic glands. Furthermore, at low magni cation, GA-FG, especially of the mixed cell type, can mimic a fundic gland polyp or a pyloric gland neoplasm 6 . It is necessary to differentiate GA-FG from fundic gland adenoma when a subset of GA-FG lacks the ability to invade or metastasize 4 .…”