Fig. 5
Radiographic, endoscopic and histologic features of a protruding lesion in the ascending colon. a: Barium enema (BE) examination shows a protruding lesion with an irregular depression. Wall rigidity under the BE profile view is present (arrow). b: High-power view of Fig. 5a. Horizontal rigidity is 4 mm (black arrow) and vertical rigidity is 0.4 mm (white arrow). c: Conventional colonoscopy shows a protruding lesion with a depression. d: Magnifying narrow-band imaging (NBI) colonoscopy for the area indicated in the box in Fig. 5c reveals an irregular surface structure and vessels. These findings are compatible with type 2B of the Japan NBI expert team classification. e: Magnifying chromoendoscopy with crystal violet solutions for the same area reveals an irregular surface structure, regarded as type VI high-irregularity of the pit pattern classification. f: Histologic examination of the resected specimen shows a well-differentiated adenocarcinoma invading the deep submucosal layer (invasion depth; 1.7 mm), lympho-vascular invasion-negative, budding grade 1, lymph metastasis-negative