Tumors of Intestines PDF

Tumors of Intestines Ahmed Almobarak  Tumors of Small Intestines The following topic will be discussed: Tumors of small intestine. Tumors of large intestine. Gastrointestinal lymphoma. Tumors of the appendix.  Background Tumors of the small intestine: Rare (3-6%...

Tumors of Intestines Ahmed Almobarak  Tumors of Small Intestines The following topic will be discussed: Tumors of small intestine. Tumors of large intestine. Gastrointestinal lymphoma. Tumors of the appendix.  Background Tumors of the small intestine: Rare (3-6% of gastrointestinal tumors). Benign tumors: – Leiomyoma. – Adenomatous polyps. – Lipoma. Malignant tumors: – Carcinoid tumor. – Adenocarcinoma.  Carcinoid Tumor Carcinoid tumors: It arises from neuro-endocrine cells (argentaffin cells), which scattered allover organs. Common sites: – Appendix, the most common. – Ileum. – Rectum. – Stomach. – Lung.  Carcinoid Tumor Gross appearance: – Small, firm, yellow-brown. – Intramural or submucosal. – Solitary in the appendix and rectum. – Multiple in other areas. Carcinoid tumor, rectum, gross  Carcinoid Tumor Microscopic: – It is formed of islands or sheets of small uniform cohesive cells with scant granular cytoplasm and stippled nuclei. – The sheets of the cells are separated by dense fibrous stroma. – The cells usually stain positive for neuroendocrine markers as chromogranin. Carcinoid tumor, microscopic  Carcinoid Tumor Clinical findings: - Usually, asymptomatic. - It may give many symptoms, due to its secretory products: Zollinger Ellison syndrome (gastrin secrertion leading to multiple peptic ulcer). Cushing syndrome (corticotropin secretion). Carcinoid syndrome (serotonin secretion). Lab: increased 5-hydroxyindole acetic acid (5-HIAA) in the urine.  Carcinoid Syndrome Carcinoid syndrome: features – Cutaneous flushing. – Diarrhea. – Abdominal cramps. – Broncho-constriction. – Hepatomegaly, due to metastases. – Tricuspid & pulmonary valve fibrosis.  Adenocarcinoma Adenocarcinoma of small intestine: It is rare. Usually encircles the bowel. Arises in the duodenum. Risk factors: – Celiac disease (gluten-sensitive enteropathy) – Crohn’s disease. – Diverticulosis.  Adenocarcinoma Tumors of large intestine: Benign tumors: Neoplastic polyps (Adenomas): – May be sessile or pedunculated. – Most of them are present in the rectum and sigmoid colon. – They may be tubular, villous or tubulo-villous. Pedunculated polyp Normal colonic mucosa (left) and tubular adenoma (right), microscopic Villous adenoma, microscopic  Familial Polyposis Familial polyposis (adenomatous polyposis coli, APC): – Hereditary disease (autosomal dominant). – There is mutation in APC gene (tumor suppressor gene, on chromosome 5) or MUTYH gene on chromosome 1. – Characterized by hundreds of polyps in the colon and may be in other sites of GIT. – It is a precancerous lesion: by age 40, virtually 100% will develop an invasive adenocarcinoma. Familial polyposis, gross  Large Intestine: Non Neoplastic Polyps Non-neoplastic colorectal polyps: – Hyperplastic polyps. – Hamartomatous polyp (juvenile or retention polyps). – Inflammatory polyps (pseudopolyps as in cases of ulcerative colitis). – Lymphoid polyps (hyperplasia of submucosal lymphoid tissue).  Large Intestine: Malignant Tumors Malignant tumors of large intestine: 1- Carcinoma. 2- Malignant lymphoma. 3- Leiomyosarcoma.  Colonic Carcinoma Colonic carcinoma: Worldwide, high in industrial areas. Occurs in males more than females 2:1. Age incidence: 50-70 years.  Colonic Carcinoma Risk factors for colonic carcinoma: – Low fiber diet. – High content of carbohydrate diet. – High red meat and animal fat diet. – Adenomatous polyps. – Hereditary polyposis. – Ulcerative colitis.  Colonic Carcinoma Sites and incidence: – Recto-sigmoid colon: 55% (the commonest site). – Cecum and ascending colon: 25% – Transverse colon: 12% – Descending colon: 8%  Colonic Carcinoma Gross appearance: – Polypoid type: in ascending colon. – Ulcerative type (any site). – Infiltrative type: in the descending colon and rectum, complicated by stenosis and obstruction. Cancer colon, gross  Colonic Carcinoma Microscopic: – Commonly it is Adenocarcinoma which may be: Well differentiated. Undifferentiated. Mucoid. Signet ring cells. – Squamous cell carcinoma. – Carcinoid tumor. Adenocarcinoma, colon, microscopic  Colonic Carcinoma Clinical manifestations: – Asymptomatic at first. – Fatigue and weakness. – Iron deficiency anemia. – Abdominal discomfort. – Progressive bowel obstruction.  Colonic Carcinoma Spread of the tumor: – Direct spread to the wall. – Lymphatic spread to the mesenteric and periaortic lymph nodes. – Blood spread to liver, lung, brain and bone. – Transcelomic spread to the ovary (Krukenberg tumor).  Colonic Carcinoma Prognosis: – 5 year survival is 100% in lesions limited to the mucosa. – 25% in invasive tumors.  Intestinal Lymphoma Gastro-intestinal lymphoma: B-cell type lymphoma. Derived from mucosa-associated lymphoid tissue (MALT). So it may called MALToma. Sites: – Stomach: 55% – Small intestine: 25% – Colon: 20%  Intestinal Lymphoma Gross appearance: – Early lesions are plaque-like. – Advanced lesions are of full mural thickness or are polypoid protruding into the lumen. Microscopic: – The neoplastic lymphocytes infiltrate and replace the normal structures. Gastro-intestinal lymphomsa, microscopic  Appendicular Tumors Tumors of the appendix: Carcinoid tumor (common). Mucinous cystadenoma (rare), secreting mucus, producing mucocele. It may rupture. Mucinous cystadenocarcinoma (rare): it causes peritoneal implants by the neoplastic mucin- producing cells leading to “pseudomyxoma peritonei” which is fatal. Thanks