Cases of invasive pattern. (a) Endoscopic examination demonstrates a small (7 mm) flat elevated lesion in the sigmoid colon. (b) Chromoscopy with indigo carmine demonstrates a definite central depression. (c) Magnification with crystal violet staining demonstrates an invasive pattern in a demarcated area. Based on these findings, the tumor was diagnosed as an early colon cancer with deep submucosal invasion, and surgical resection was recommended. Histopathological examination of the resected specimen demonstrated well differentiated adenocarcinoma, invasive to the submucosa (sm deep; 4000 μm). (d) A sessile lesion Is(+IIc), 15 mm in diameter, identified in the upper rectum. (e) Chromoscopy with indigo carmine: reddish change and slight depression are observed on the surface of the tumor. (f) Magnification with crystal violet staining demonstrates an invasive pattern. Histopathological examination of the resected specimen demonstrated well differentiated adenocarcinoma (sm deep; 4500 μm).
