GIT 6 Dr Basim 4 Mic features of

GIT. 6 Dr. Basim

4. Mic features of Crhon disease: a. inflammation, transmural involvement, (with neutrophilic infiltration in the epithelial layer & accumulation within crypts to form Crypt abscess. b. ulceration of mucosa. c. chronic mucosal damage (glandular destruction…… atrophy & metaplasia). d. granuloma formation. e. fibrosis of all muscular layers & extend to the omentum. Clinical features l Recurrent episodes of diarrhea, crampy abdominal pain, & fever (days – weeks). l Sometimes misdiagnosed as acute appendicitis. l Melena in 50% of cases on colonic involvement. l 20% of cases have continuous active disease (most of cases are relapsing).

Complications of Crhon disease: 1. Intestinal obstruction (due to stricture formation). 2. Fistula formation with other bowel loops, urinary bladder, vagina abdominal wall. 3. Abdominal abscesses or peritronitis. 4. Malignant transformation (less than UC). Ulcerative Colitis: Is an ulceroinflammatory disease affecting the colon but limited to the mucosa & submucosa. l Incidence: UC more common than CD. l Geographic distribution: western more common than eastern areas. l Sex & race: no sex predominance, white more than non white. l Age: any age (but peak incidence 20 -25 years). l Site within colon: rectum or rectosigmoid colon only in 50% of case. l Colonic involvement: in UC is continuous (no skip lesion); while in CD is segmental.

Gross: 1. Mucosa is inflamed, hyperemia, edema, & friable & ease to bleed…. . & in severe cases there are extensive & broad based ulceration of mucosa…. . then the bases ulcers are interconnected…. Form undermined tunnel. 2. Isolated islands of regenerating mucosa bulge upward to create (Pseudopolyps). 3. Perforation & pericolonic abscess formation. 4. Toxic megacolon due to destruction of muscular layers & neural plexus. 5. with chronic disease …… flattened mucosal surface…. Metaplasia & Dysplasia. Mic: l Mucosal inflammation, ulceration & chronic mucosal damage. l Crypt abscess formation. l No granuloma l Full thickness ulceration with granulation tissue formation.

Complications: 1. Massive hemorrhage (bleeding per rectum). 2. Perianal abscesses. 3. Colorectal carcinoma. Risk factors for colonic carcinoma in UC patient: 1. Pancolitis (risk is of 10%). 2. Long duration of disease (more than 20 years…. 10%). Clinical features: Chronic relapsing attacks of bloody mucoid diarrhea. Cramping lower abdominal pain with tenesmus. Main differences between CD & UC: 1. Gross features: Site …. In CD is mainly colon +/- ileum. …. In UC is only colon. Distribution …. In CD skip lesions. …. In UC diffuse lesions. Stricture: …. In CD usually present. …. . In UC is rare.

Wall thickness… in CD thickened. … In UC is thinned. Dilatation: …. In CD (yes). …. In UC (also yes). 2. Mic: Pseudopolyps: …. . in CD less common. …. . in UC are common. Ulcers: …. In CD are deep linear. …. In UC are superficial. Lymphoid reaction: …………………. in CD is marked (enlargement of peyer's patches)……. . in UC is mild. Fibrosis: …… in CD is marked. …… in UC is mild. Granulomas: …. In CD marked …. . in UC none Fistulae/ sinuses: …. . in CD 40%- 60%. …… in UC (No). 3. Clinical features: Malignant transformation: …. . in CD less

Tumors of small & large intestines: Tumors of small intestine are generally rare especially epithelial tumors; the most common malignant tumor is lymphoma. While the epithelial tumors of the large intestine are common which are: 1. Benign tumors (adenomas). 2. Malignant tumors (carcinomas). Tumors of large intestine: Polyp: is a tumor mass that protrudes into the lumen of the gut & are of two types: I. Non neoplastic polyps: Result from inflammation with abnormal mucosal maturation. Form 90% of epithelial tumors. Don't have malignant potential. They are of two types:

A. Hyperplastic polyp: l Small size (less than 5 mm). l Nipple shape, hemispheric shape. l They are multiple. l Age: between 50 -60 years. l Site|: at rectosigmoid region. B. Juvenile polyp: l Size 1 -3 cm. l Usually single. l Mainly children. l Site at the rectum. l Presented as bleeding per rectum. II. Neoplastic polyps (adenomatous): l Result from epithelial proliferation & Dysplasia. l They are slowly growing tumors & they are called ADENOMAS. l They have malignant potential & can change to carcinoma.

Divided into three types according to the Histology: : 1. Tubular adenoma. 2. Villous adenoma. 3. Tubulovillous adenoma. A. Tubular adenoma: l Single or multiple. l 2. 5 cm. l It has a pedicle (stalk). l At rectosigmoid area. l Mic: proliferation of glands. l Rare malignant transformation. (small size). B. Villous adenoma: l Usually single. l Large size (10 cm). l Not have pedicle (sessile), with wide broad base. l Rectum & rectosigmoid area.

Mic: papillae (finger like projections). C. Tubulovillous adenoma: Contain both elements of A & B. Characteristics of malignant transformation of Adenoma: 1. Size of adenoma, the larger the size; the greater risk of malignancy. 2. Histological type, villous adenoma carries more risk than tubular. 3. Number of adenoma: increase number…. Increase the risk. 4. Dysplasia, severe Dysplasia carry high risk. Familial adenomatous polyposis: l Autosomal dominant disorder. l Characterized by the presence of innumerable adenomatous polyps (at least 100 polyp are counted to diagnosed the disease). l The risk to develop malignancy is 100%. l Treatment needs prophylactic colectomy. l Mic: tubular adenoma.

Colorectal carcinoma l 98% 0 f cases are adenocarcinoma. l Considered as second most common cause of death from cancer. l Western more than astern areas. l Age 60 – 70 years. Etiology & pathogenesis: 1. Premalignant conditions: l Adenomas (villous). l Ulcerative colitis. 2. Genetic causes: Like in familial adenomatosis polyposis (100% risk). 3. Environmental causes: (mainly dietary causes) l Fat intake: high fat intake. l Carbohydrate: high intake. l Fibers: low fiber diet…… high risk (delay in passage of stool…. More time of contact of mucosa to the carcinogens. l Vitamins: low vitamins A, C, E.

Gross: 50% of cases are at the rectosigmoid area & appear as: 1. Polypoid mass (cawliflower…. This more common on the right side of colon). 2. Annular lesion: encircling lesions which produce ring constrictions of bowel…… on left side. Mic: Well…. to poorly differentiated adenocarcinoma. Clinical features: l Asymptomatic. l Change in bowel motion. l Bleeding per rectum. l Intestinal obstruction. l Other features like anemia, weight loss.

Spread: 1. local 2. lymphatics. 3. hematogenous. Prognosis: Staging of tumor is important at the time of diagnosis: In 1937 Dukes proposed a staging system. In 1954 Astler & Coller created another staging system with further modifications Dukes system: Stage A: the tumor involves the wall of the bowel only. Stage B: the tumor extends through the wall. Stage C: there is lymph nodes involvement. Astler & Coller staging system: (recommended nowdays) Stage A: limited to the mucosa. Stage B 1: extend into muscularis propria but not invade it. Stage B 2: penetrate the muscularis properia. Stage C 1: B 1 + lymph nodes involvement. Stage C 2: B 2 + lymph node involvement. Stage D: distant metastases.

Carcinoid tumor: l Arise from neuroendocrine cells within the wall of bowel. l Can produce hormones (serotonine, gastrin). l Can stain by silver stain (argentaffinoma). Sites: l Appendix. l Ileum. l Stomach. l Rectum. Carcinoid syndrome: Patient with carcinoid tumor develops attacks of flushing, diarrhea, brochspasm (action of serotonin hormone). These features occur when the patients develop liver metastases (failure of detoxification of these hormones.

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