Colorectal Polyps PDF
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This document provides an overview of colorectal polyps and polyposis syndromes, including their definitions, types, classification, malignant potential, investigations, and management strategies. It delves into the histologic patterns, sizes, degrees of dysplasia, and the adenoma-carcinoma sequence involved in the progression of these polyps to cancer.
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Colorectal polyps and polyposis syndromes What is the meaning of a polyp? A polyp is a lesion arising from the mucosa and protrudes into the lumen of a viscus. (GIT polyps: oral., pharyngeal, esophageal, gastric, small intestinal, colorectal & anal). Other polyps: nasa...
Colorectal polyps and polyposis syndromes What is the meaning of a polyp? A polyp is a lesion arising from the mucosa and protrudes into the lumen of a viscus. (GIT polyps: oral., pharyngeal, esophageal, gastric, small intestinal, colorectal & anal). Other polyps: nasal. Urinary bladder……… GIT polyps may be sessile or pedunculated. Extended Modular Program 2 Polypoid lesions are not true polyps but Some polyp-like lesions may arise from the submucosa like the lipoma or GIST and these are not polyps. They are usually sessile lesions elevating the overlying mucosa. So all polyps are polypoid lesions and not all polypoid lesions are polyps. Polyposis syndromes are inherited diseases associated with multiple polyps of the gastrointestinal tract together with extracolonic pathology. The most famous inherited polyposis syndromes are familial adenomatous polyposis (FAP), hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome) and Peutz-Jegher syndrome. 3 Neoplastic Polyps (Adenomas) Adenomas are benign tumours of the colorectal mucosa They can be sessile or pedunculated, solitary or multiple. There are three histologic types of adenomas: - Tubular adenomas (75%): The cells organize themselves into tubular structures - Villous adenomas (15%): The cells organize themselves into finger like structures. - Tubulovillous adenomas (10%): Mixture of arrangement into tubular and finger like structures. Adenoma- carcinoma sequence Adenomas are premalignant and can turn into colorectal cancer by passing through the following stages: normal colonic mucosa mucosal hyperplasia adenoma formation & growth dysplasia invasive cancer. This process is known as adenoma- carcinoma sequence. It takes about 5 to 15 years for adenoma carcinoma sequence to be completed and normal mucosa change to cancer. The malignant potential of adenomas is related to - Histologic pattern: Villous adenomas are more likely to turn malignant (35-40%), tubular adenomas are less likely to turn malignant (
