Gastric Adenocarcinoma of the Fundic Gland Type: Update and Literature Review.

Objectives: Gastric adenocarcinoma of the fundic gland type (GA-FG) is a newly described entity with a lack of awareness amongst general surgical pathologists and this review highlights the key features and controversies associated with this uncommon neoplasm.

Methods: A literature search through PubMed using synonyms for GA-FG was conducted to obtain 111 cases.

Results: GA-FG is a well-differentiated neoplasm of oxyntic mucosa, that is comprised of chief cells and parietal cells. Chief cell differentiation is highlighted with Muc-6, RUNX3, and pepsinogen. Parietal cells are highlighted with H+/K+ ATPase and PDGFRA-α. Association with Helicobacter infection, chronic gastritis, intestinal metaplasia, or gastric atrophy is not seen. Most GA-FGs are confined to the mucosa. Deeper invasion, lymphovascular invasion, nodal metastasis, and extragastric spread are uncommon.

Conclusions: GA-FGs are rare lesions that typically follow a benign course. However, despite features of malignancy in some cases, complete surgical excision, sometimes with endoscopic mucosal resection, seems adequate treatment.