Transcript 幻灯片 1

Tumours of the large intestine
done by
Dr layth Q
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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 .
• 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: 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