Most polyps can be removed through the endoscope. They are then examined under the microscope. It is important to determine whether or not they contain cancer, if they are of a type that has malignant potential, and if they have characteristics that make them more likely to be associated with cancer, either in another polyp at the same time or in polyps that may form in the future (for example, are villous or serrated).The results of the colonoscopy and histologic examination are important because they determine the need for increased frequency of screening colonoscopy in the future (for example, adenomatous polyps). If there is cancer already present in the polyp it is important to determine how deep into the wall of the colon the cancer has spread. If it extends deeply, it is more likely that the cancer has spread to lymph nodes further away. If there is deep extension of the cancer, it may be necessary to do additional endoscopic resection of the area of colon where the polyp was or to surgically remove the section of colon, in order to be certain that all of the cancer has been removed. Nearby lymph nodes also may be removed and examined to identify any spread of the cancer beyond the colon.If a genetic mutation is suspected, it is looked for by genetic testing on a portion of the biopsy, and, if present, relatives should be screened for the same mutation. If present, the relatives should undergo screening colonoscopy and more frequent surveillance colonoscopy.It is recommended that patients with FAP and other polyp syndromes consider having their colons removed prophylactically to prevent the development of cancer.