Tumours of the large intestine
done by Dr layth QBenign: Polyp,is protrusion of the mucosa. Classification of intestinal polyps: Inflammatory. Inflammatory polyps ( pseudopolyposis in ulcerative colitis) Meta plastic. Meta plastic or hyperplastic polyps Hammartomatous. Peutz- jet hers polyp Juvenile polyp Neoplastic. Adenoma. Tubular,tubulovillous,villus Adenocarcinoma,carcinoid tumour
Adenomatous polyp: Varies from tubular to villus.may be solitary and the cause of rectal bleeding or sometimes villous and the cause of hypo Kalaemia and Hypoalbuminaemia .the risk of malignancy increases with their size .
Adenomatous polyp: Varies from tubular to villus.may be solitary and the cause of rectal bleeding or sometimes villous and the cause of hypo Kalaemia and Hypoalbuminaemia .the risk of malignancy increases with their size
Familial adenomatous polyposis: defined to have more than 100 polyps and multiple extra intestinal manifestation like endodermal( adenomas of duodenum,stomach) or ectodermal like epidermoid cysts ,brain tumours . And mesodermal like desmoid,dental problems,or osteomas.
Gardener's syndrome: familial polyps with epidermoid cyst and desmoid tumours.
Features of familial adenomatous polyposis: Autosomal dominant More than 100 colonic adenomas Prophylactic surgery Polyps and malignant tumours can develop in the duodenum and small bowel.:: Treatment Colectomy with ileorectal anastamosis Restorative proctocolectomy with ileal pouch Total removal with end ileostomy.Lynch syndrome: characterised by increased risk of colorectal cancer and also cancer of endometrium,ovary,stomach and small intestine.
Malignant: Epidemiology in UK colorectal cancer is the second most common cause of cancer death . Aetiology: the accepted model arises from adenomatous polyps after genetic mutation influenced by environmental factors . The p53 gene mutated in carcinomas. Linkage between diet and colon cancer Ulcerative colitis Suggested after cholecystectomy increase risk Also increased risk after ureterosigmoidostom
Pathology: Macroscopic Four types; annular,tubular,ulcer,cauliflower. Microscopic It is adenocarcinoma originating in the colonic epithelium