Anatomically, the microvascular architecture is formed by the capillaries and collecting venules (CVs). The morphology of each capillary is that of a dark brown polygonal closed loop. These loops anastomose repeatedly with each other, forming a regular honeycomb-like subepithelial capillary network (SECN) pattern. In the normal fundic glandular epithelium, almost 100 % of the time, regularly arranged cyan-colored collecting venules (CVs) can be identified. We can see the regular SECN draining into CVs in the superficial mucosal layers [1, 2].

Anatomically, the mucosal surface is made up of the marginal crypt epithelium (MCE), crypt openings (COs), and the intervening part (IP) in between. The epithelial morphology is visualized as semitransparent white belt-like structures, showing a circular or oval shape. In the center we see brown oval COs, surrounded by MCE.

The VS (relationship between the microvascular architecture and microsurface structure) is an epithelium within vessel pattern, with oval areas of epithelium seen within polygonal subepithelial capillaries (SECs). For convenience’s sake, we refer to this pattern of oval epithelial areas inside blood vessel closed loops as “VS of gastric body type.”

Anatomically, the microvascular architecture is formed by the capillaries and CVs, but the latter are rarely observed from the mucosal surface [3, 4]. The morphology of each capillary is that of dark brown coil-shaped open loops. Although it has been shown anatomically that these loops anastomose repeatedly with each other under the epithelial surface, subepithelial anastomoses are not often visualized. Only rarely do the capillaries anastomose together to form a subepithelial reticular pattern.

Anatomically the mucosal surface is made up of the MCE and the IPs surrounded by the MCE. As described in earlier chapters, we rarely observe dark brown COs in the antral mucosa. The MCE morphology is usually polygonal but may be curved or linear.

The VS is a vessel within epithelium pattern, with coil-shaped SECs within polygonal MCE. For convenience’s sake, we refer to this pattern as “VS of gastric antral type.”