Indications for colorectal resection for adenoma before and after polypectomy.

Adenomas presenting in colon and rectum require different strategies. Those in the rectum are accessible to local endoanal excision while those in the colon can be removed by endoscopic polypectomy. Essentially the decision in both cases centres around the risk of malignancy. Does the tumour itself contain a focus of malignancy? Where invasion has been demonstrated in the tumour, are the regional lymph nodes involved? Rectal adenomas can be assessed by clinical examination, rectal ultrasound and magnetic resonance imaging. Colonic adenomas on the other hand, are assessed by endoscopic appearances amplified by chromo- and zoom-endoscopy techniques and by endoscopic endosonography. In both locations the decision for surgical resection may be necessary in two clinical circumstances: the preoperative assessment of invasion and following the histopathology report where invasion has been demonstrated. With any adenoma with malignant change, a surgical opinion should be obtained. The decision for surgery depends on the risk of failure of the local excision balanced by the risk of morbidity and mortality following major surgery. Patients' wishes in the light of discussion of clinical and pathological prognostic factors are crucial in making the decision. Surgery is more frequently applied for early colonic than rectal cancers. This is due to two main factors: resective colonic surgery has less complications and mortality than anterior resection and transanal local excision may be more radical than endoscopic colonic polypectomy because it excises the full-thickness rectal wall.