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Tumors of Intestine s

Tumors of Intestine s. Introduction. Overall, colorectal cancer ranks second only to bronchogenic carcinoma among the cancer killers. Adenocarcinomas constitute the vast majority of colorectal cancers and represent 70% of all malignancies arising in the gastrointestinal tract. T erminology.

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Tumors of Intestine s

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  1. Tumors of Intestines

  2. Introduction • Overall, colorectal cancer ranks second only to bronchogenic carcinoma among the cancer killers. • Adenocarcinomas constitute the vast majority of colorectal cancers and represent 70% of all malignancies arising in the gastrointestinal tract.

  3. Terminology • •A polyp is a tumorous mass that protrudes into the lumen of the gut; traction on the mass may create a stalked or pedunculated polyp. • Alternatively the polyp may be sessile, without a definable stalk. • •Non-neoplastic Polyps • abnormal mucosal maturation, • inflammation • do not have malignant potential (excl.Peutz-Jeghers) • •NeoplasticPolyps: • adenomatous polyps, or adenomas, • precursors of carcinoma.

  4. Non-neoplastic (benign) Polyps • Hyperplastic polyps • Hamartomatous polyps • Juvenile polyps • Peutz-Jeghers polyps • Inflammatory polyps • Lymphoid polyps

  5. Neoplastic epithelial lesions • Benign lesions: • Neoplastic polyp • Adenoma • Malignant lesions: • Adenocarcinoma • Carcinoid tumor • Anal zone (anorectal) carcinoma • Mesenchymal lesions (benign/malignant) • Lymphoma

  6. Common Hyperplastic polyps Adults Rectosigmoid Multiple Nipple-like, Small protrusions (5 mm) Abundant crypts. Juvenile polyps Children Rectum Single Round mass 1-3 cm Dilated cystic glands. Non-neoplastic (benign) Polyps

  7. Hyperplastic polyp Polyps Juvenile polyp

  8. Sessile Pedunculated

  9. Small-pedunculated; large-sessile Colon Familial predisposition Risk of carcinoma Subtypes: Tubular Villous Tubulovillous Malignancy: Rare: tubular adenoma less than 1 cm High: sessile villous adenomas more than 4 cm Dysplasia: villous adenomas. Adenomas

  10. Tubular adenomas: Colon (rectosigmoid) Small-sessile; large-pedunculated Stalk is covered by normal mucosa Tumor is composed of neoplastic epithelium Intramucosal Ca or invasive Ca. Villous adenomas: Rectum/rectosigmoid Larger than tubular Sessile Cauliflower-like Dysplasia  Ca. Tubulovillous adenomas: Peduculated or sessile Mix of tubular and villous patterns Dysplasia Malignancy.

  11. Adenoma

  12. Peutz-Jeghers Syndrome Multiple polyps (polyposis coli) large, firm polyps with a tree-like structure distinctive freckles on thelips, palms, and genitals risk for colon cancer. Turcot's syndrome Multiple polyps brain tumors. Gardner's syndrome Multiple polyps minor birth defects risk for other tumors (notably mesenchymal). Cowden's syndrome Multiple polyps Risk of tumors of: Thyroid Breast Uterus Skin. Familial polyposis syndromes

  13. Part OneTumors ofSmall Intestine

  14. Small Intestine tumors: • Small intestine -75% but tumors – 3-6% • Benign tumors (common) • Adenoma(25%), lipoma & leiomyoma. • Malignant tumors (rare; <1%) • Adenocarcinoma of Duodenum or Jejunum, Carcinoid, Lymphoma, Sarcoma • Present at late stage, 70% 5 year survival.

  15. Classification • Non neoplastic polyps • Hyperplastic, lymphoid & hamartomatous • Inflammatory • Neoplastic – epithelial • Benign – Adenoma(ampulla of Vater) • Malignant – Adenocarcinoma, carcinoid • Neoplastic – Mesenchymal • Benign - Lipoma, leiomyoma, neuroma, angioma • Malignant – Leiomyosarcoma, liposarcoma. • Lymphoma

  16. Benign tumors: Lipoma • Most common • Mature adipose tissue

  17. Napkin-ring or polypoid Duodenum (ampulla of Vater’s) Spreading: Regional lymph nodes Liver Obstructive jaundice. Adenocarcinoma

  18. Tumors ofColon & Rectum

  19. Colorectal carcinoma • Adenocarcinomas (98%) • often arises in one of the benign neoplastic colonic polyp • risk factors • (1) mild hereditary defects in anti-oncogenes lost in colon cancer, • (2) years of eating the typical western diet. • Low content of vegetables • High content of refined carbohydrates • High content of fat (animal) • Low content of micronutrients (vitamins A, C, E).

  20. Morphology Proximal colon tumors: polypoid Cecum and ascending colon: exophytic Distal colon: napkin-ring Progression: slow (years) Types: Gut: Adenocarcinoma Mucin production Anal zone: Squamous cell carcinoma Spreading: Regional lymph nodes Liver

  21. 2% of colorectal malignancies. Origin:Neuroendocrine cells (paracrine, Kulchitsky, enterochromaffin, neurosecretory, chromaffin) Location: gut (common in appendix) pancreas or peripancreatic tissue, lungs, biliary tree liver. Rectal and appendiceal carcinoidsalmost never metastasize The classic carcinoid syndrome (serotonin) (1) wheezing (asthmatic); (2) flushing (vasomotor); (3) fibrosis (cardiac, pulmonic, pleural, pelvic); (4) intestinal hypermotility. Carcinoid Tumors

  22. Midgut carcinoids: small intestinal, appendiceal, most colonic carcinoids. These are usuallyargyrophil (hormonally active). Foregut carcinoids: lung, duodenal, biliary carcinoids. These are almost never argyrophil (hormonally inactive).

  23. Less common than carcinomas Westernlymphomas are usually familiar B-cell lymphomas Mediterranean lymphomas usually feature plasmacytoid differentiation (a subset is alpha-heavy chain disease). Sprue-associated lymphoma exhibits T-cell markers Gastrointestinal lymphoma

  24. Lymphoma

  25. THANK YOU

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