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Forth stage
Surgery
Lec-4
د
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ليث
الحرباوي
4/18/2016
Tumors of the large intestine
Benign:
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.
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.
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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:
Characterized 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