[Malignant polyps of the colon and rectum]

It is important for the general surgeon to have a clear idea of what is a malignant polyp and factors determining its clinical management. A malignant polyp is either sessile or pedunculated and harbors an invasive carcinoma which means that malignant cells have penetrated into or through the muscularis mucosae. Carcinoma in situ, intramucosal carcinoma, superficial carcinoma, carcinoma within the the mucosa or lamina propria are terms commonly used that must be distinguished from true invasive malignancy. These polyps should be treated by complete polypectomy and followed up as in a benign polyp. A polyp with invasive carcinoma requires careful evaluation to make a decision if simple polypectomy is sufficient treatment or whether surgical treatment is indicated. This decision is based on the risk factors such as a residual/recurrent tumour and the risk of lymph node metastases. We present a current review of the literature on the subject.