Small invasive colon cancer with adenoma observed by endocytoscopy: A case report

Figure 1 The colonoscopy. A: Colonoscopy revealed a 12-mm reddish polyp in the sigmoid colon; B: Indigo carmine staining revealed a depression on the left and a flat area on the right side.

Figure 2 Endocytoscopy of the lesion. A: On the left side of the lesion (depression), unclear gland formation and agglomeration of distorted nuclei strongly stained by methylene blue were visible with endocytoscopy, suggesting a submucosal invasive cancer; B: On the right side of the lesion (flat area), slit-like smooth lumens and a regular pattern of fusiform nuclei were found, suggesting an adenoma.

Figure 3 Final histological diagnosis: Adenocarcinoma (well to moderately differentiated tubular adenocarcinoma) with adenoma, with 2407 μm depth of invasion (T1); negative for lymphovascular invasion, grade 1 budding, and negative horizontal and vertical margins.