II. Gastroscopic Classification

II. Gastroscopic Classification

Early gastric cancer endoscopically can be divided into three types.

Type I (protruding type): Accounts for 13.6% of early gastric cancer. The affected gastric mucosa slightly protrudes, resembling small polyps without stalks or with short stalks. The surface is uneven, edges are unclear, and bleeding may occur; if larger than 2 cm, malignancy should be strongly suspected.

Type II (superficial type): Accounts for 76.8%. Has three subtypes:

Type IIa (protruding superficial type): Lesion slightly bulges above the mucosal surface, height not exceeding 5 mm, small area, smooth surface.

Type IIb (flat superficial type): Lesion is level with the mucosa, hardest to detect, with uneven size and shape of the lesser curvature, and rough, granular texture of the affected mucosa.

Type IIc (depressed superficial type): Most common, with superficial depression, uneven base, visible aggregated mucosa, but aggregation lines may be disrupted.

Type III (ulcerative type): Accounts for 9.6% of early gastric cancer. Depth of depression is greater than Type IIc, with ulceration and fine cancer infiltration around the edges. Ulcers can resemble benign gastric ulcers.

Types I and IIa are also called polypoid types, while Types IIc and III are collectively referred to as ulcerative types. Types I and II affect only the mucosa, whereas Type III has already invaded the submucosal layer.