Colonic adenomas over 2cm are not necessarily malignant, and the determination of malignancy needs to be based on pathological examination results rather than tumor size. Colonic adenomas are common intestinal tumors. Colonic adenomas can be divided into tubular adenomas, tubular choriocarpous adenomas and choriocarpous adenomas, which are mostly benign, with higher malignant rate of choriocarpous adenomas and tubular choriocarpous adenomas. Therefore, when a colonic adenoma grows to 2 cm, it is not necessarily malignant. For malignant tumors, it is usually necessary to characterize them based on pathological findings. In addition, preliminary diagnosis can be made from the texture of the tumor, the border situation, and the appearance and morphology. If the tumor has hard texture, unclear border and irregular morphology, it can be initially diagnosed as malignant tumor. Therefore, the size of the tumor is not a judgment indicator of malignancy. When colonic adenoma is present, tissue biopsy and pathological examination should be carried out as early as possible to clarify the benignity and malignancy as early as possible and to carry out surgical treatment.