If endoscopic histology confirms that the adenoma is cancerous, the entire polyp should be removed for histological examination whenever possible (unless it is difficult to remove it completely by endoscopy or if it is diagnosed as an invasive carcinoma), so that the pathologist can provide complete histological information to the clinic, because it is blind to perform invasive surgical treatment with only a biopsy of a part of the polyp, especially if the tumor is located in the rectum and the treatment is directly related to This is especially true if the tumor is located in the rectum and treatment is directly related to anal function. Frozen sections assist in making immediate treatment decisions. A correct pathologic diagnosis is essential in determining the treatment of a cancerous polyp. Therefore, the surgeon needs to work closely with the endoscopist and pathologist to determine whether the adenoma is completely excised and to understand its size, pathologic classification, histologic type, degree of differentiation of cancer cells, depth of infiltration, presence of cancer at the cut edge, and presence of infiltration of lymphatic vessels and veins in order to make the correct judgment. The factors that determine the treatment plan are as follows: a. Depth of cancer infiltration Carcinoma in situ confined to the mucosa has no metastatic ability, so if complete adenoma resection has been performed, resection is not necessary. For invasive carcinoma that has infiltrated into the mucosal muscle layer, bowel resection including the lymph nodes at station 1 should be performed for those with wide base. Cooper emphasized the significance of the length of the tip when deciding whether to perform further surgical treatment, and he classified polyps as long tip (≥3 cm), short tip (<3 mm), and no tip. Those whose carcinoma was confined to the head of long-tipped or short-tipped polyps had no lymph node metastasis or local recurrence; those whose carcinoma was in short-tipped polyps at the cut edge or in non-tipped polyps near the cut edge had 6/24 (25%) metastasis or recurrence. The current controversy in the treatment of adenoma carcinoma is actually a disagreement on whether early infiltrating carcinoma with a tipped, well- or moderately differentiated cell, and uninvolved lymphatic vessels and vasculature requires further management; Colacchio concluded that it is not possible to accurately predict the circumstances in which lymphatic metastasis may occur and recommended bowel resection for all adenomas with carcinoma, including early infiltrating carcinoma. Eckardt et al. compared the recurrence rate and 5-year survival rate after endoscopic polypectomy for simple polyps, polyps with severe atypical hyperplasia, and polyps with infiltrating carcinoma, and there were no statistical differences, indicating that endoscopic resection is also safe and reliable. Histology of carcinoma 1. tubular adenoma: When the carcinoma invades the submucosa, there is a theoretical possibility of metastasis because of the rich lymphatic vessels and blood vessels in the submucosa, however, clinical experience has confirmed that the lymphatic metastasis rate is very low when tubular adenoma invades the submucosa, generally less than 5%. Therefore, if the invasive carcinoma is limited to the head of tubular adenoma or mixed adenoma with tip, resection of the tumor is sufficient. If the cancer is positive at the cutting edge or very close to the cutting edge, the pathological examination shows that the lymphatic vessels or blood vessels are invaded or there is cancer embolism, and the cancer is low-differentiated or undifferentiated cancer, then it should be treated according to the principles of colorectal cancer treatment. 2.Villous adenoma: infiltration occurs in 30% of carcinoma cases, and once infiltrative carcinoma occurs, lymph node metastasis can account for 16-39% of all carcinoma cases, therefore, villous adenoma with infiltrative carcinoma on biopsy should be treated according to the principles of colorectal cancer. 3.Mixed adenoma: The treatment of mixed adenoma with invasive carcinoma should be based on: (1) Tip: for those with a tip, the treatment principle is the same as that of tubular adenoma; for those without a tip, they should be treated according to the principle of carcinoma of villous adenoma. (2) The proportion of villous components: If there are more villous components, the treatment should be based on the principle of carcinoma of villous adenoma. (3) Differentiation degree and vascular invasion Lowly differentiated carcinoma or lymphatic or vascular infiltration confirmed in tissue section is prone to metastasis and local recurrence, and should be surgically removed according to colorectal cancer. In 1983, Cooper reported 56 cases of cancerous polyps resected by fiberoptic colonoscopy, including those with cancer on the cutting edge and those with cancer near the cutting edge (within 0.8 cm). 34 cases were re-excised and 5 cases (14.7%) were found to have lymph node metastasis and 2 cases had liver metastasis. V. Patient's age and systemic condition According to the patient's age and systemic condition, the risk of radical surgery and the possibility of recurrence were weighed, and individual evaluation was performed to decide the treatment plan. In conclusion, the treatment of adenoma carcinoma should be "individualized" and "multi-parameter" in order to minimize treatment errors.