5. Management of malignant polyps

Malignant polyp is a term that is used when a polyp is removed by colonoscopy that appears grossly benign but has adenocarcinoma identified histologically (Fig. 1). The clinical issues in this setting are more difficult than in a patient who has had a surgical resection because of a large sessile polyp or suspected malignancy where a surgical specimen and adjacent lymph nodes are available for staging. The management of patients with malignant polyps has assumed increased importance in recent years as a result of more widespread screening in the general population, and especially with introduction of colonoscopy as a screening option [1,2]. A decision must be made in each of these patients whether to consider the colonoscopic polypectomy curative or refer the patient for surgery. This decision is compounded when an asymptomatic person has been induced to have a screening test that uncovers the unsuspected pathology. Management decisions require an assessment of the pathology, risk of adverse outcome, risk of surgery and colonoscopic follow-up, and the available surgical options. There are additional considerations in high-risk patients, e.g. those with a family history suggesting hereditary non-polyposis colorectal cancer (HNPCC), long-standing inflammatory bowel disease, and familial polyposis. This chapter deals primarily with the average risk patient.