The adenomatous
colonic polyp, a neoplastic lesion, is the precursor of most if not all
carcinomas of the colon and rectum. Confirmatory evidence is derived from epidemiological, histological and clinical data demonstrating a close parallelism between
adenomas and
cancer of the colon. Based on current knowledge, all
colonic polyps should be removed to prevent the development of
colonic cancer. However, since the risk of
malignancy within an
adenoma is related to its size, histology and the degree of dysplasia, practical considerations dictate that all
polyps 1 cm in diameter or larger should be removed upon their detection by barium enema or colonoscopy since such
adenomas are the ones most likely to contain
malignancy. The endoscopic removal of colon
polyps can be efficiently and safely accomplished when established principles of colonoscopy and
electrosurgery are followed. This technique requires the proper equipment, a skilled endoscopy assistant, and an experienced endoscopist with the ability to adeptly perform colonoscopy, an understanding of the basic concepts of
electrocautery and knowledge of the various structural configurations of
colonic polyps. Colonoscopic polypectomy will avoid the need for surgical resection in most instances. Management of the malignant
colonic polyp remains controversial. The patient with a sessile or pseudo-pedunculated
polyp containing invasive
cancer should undergo colonic resection. Surgery is not necessary for the majority of patients whose pedunculated
adenomas contain invasive
cancer, unless the
malignancy is poorly differentiated, the
cancer invades lymphatics or vascular channels, or tumour is seen at or near the
resection margin. Surveillance colonoscopy after endoscopic polypectomy should be performed in most instances within one year to look for recurrent tumour, missed
polyps or a metachronous
adenoma. Subsequently, colonoscopy should be performed every two years in patients with multiple index
polyps, and every three years after removal of a single index
adenoma.