Fig. 2

Endoscopic and histologic findings of case 1. a: Colonoscopy displayed a 10 mm laterally spreading tumor in the ascending colon. Most of the area of the polyp showed a flat-elevated surface with a mucous covering while the central portion displayed a depressed appearance (black arrows). b and c: Endoscopic images after the spraying of indigo carmine dye revealed a type II pit pattern in both the elevated and depressed areas (black arrows). d: A microscopic image showed typical histologic features of an SSA/P, such as dilatation and branching of basal crypts except for a central depression (H&E staining, x40)