Intestinal polyp

A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer.Microvesicular hyperplastic polyp. H&E stain.Microvesicular hyperplastic polyp. H&E stain.Traditional serrated adenoma. H&E stain.Gross appearance of a colectomy specimen containing two colorectal polyps and one invasive colorectal carcinomaMicrograph of a tubular adenoma, the most common type of dysplastic polyp in the colon.Micrograph of a sessile serrated adenoma. H&E stain.Micrograph of a Peutz-Jeghers colonic polyp – a type of hamartomatous polyp. H&E stain.Micrograph of a tubular adenoma – dysplastic epithelium (dark purple) on left of image; normal epithelium (blue) on right. H&E stain.Micrograph of a villous adenoma. These polyps are considered to have a high risk of malignant transformation. H&E stain. A colorectal polyp is a polyp (fleshy growth) occurring on the lining of the colon or rectum. Untreated colorectal polyps can develop into colorectal cancer. Colorectal polyps are often classified by their behaviour (i.e. benign vs. malignant) or cause (e.g. as a consequence of inflammatory bowel disease).They may be benign (e.g. hyperplastic polyp), pre-malignant (e.g. tubular adenoma) or malignant (e.g. colorectal adenocarcinoma). Colorectal polyps are not usually associated with symptoms. When they occur, symptoms include rectal bleeding, bloody stools, abdominal pain and fatigue. Due to chronic blood loss from rectal bleeding and bloody stools, they sometimes present with iron deficiency anemia. Another symptom might be increased mucous production especially those involving villous adenomas. Copious production of mucous causes loss of potassium that can occasionally result in symptomatic hypokalemia. A change in bowel habits may occur including constipation and diarrhoea. Occasionally, if a polyp is big enough to cause a bowel obstruction, there may be nausea, vomiting and severe constipation. Polyps are either pedunculated (attached to the intestinal wall by a stalk) or sessile (grow directly from the wall). In addition to the gross appearance categorization, they are further divided by their histologic appearance as tubular adenoma which are tubular glands, villous adenoma which are long finger like projections on the surface, and tubulovillous adenoma which has features of both. Several genes have been associated with polyposis. These include GREM1, MSH3, MLH3, NTHL1, RNF43 and RPS20.