Intestinal Diseases-1 PDF

Intestinal diseases-1  Intestinal diseases (ID 1) The following diseases will be discussed: Idiopathic intestinal inflammations. Appendicitis. Diverticula of the intestine. Congenital mega colon (Hirschsprung’s disease)  ID 1 Idiopathic intestinal inflammations: Inc...

Intestinal diseases-1  Intestinal diseases (ID 1) The following diseases will be discussed: Idiopathic intestinal inflammations. Appendicitis. Diverticula of the intestine. Congenital mega colon (Hirschsprung’s disease)  ID 1 Idiopathic intestinal inflammations: Include the following diseases: – Regional enteritis “ Crohn’s disease”. – Ulcerative colitis.  ID 1 Regional enteritis: “Crohn’s disease” CD: Definition: it is a chronic non specific granulomatous disease. Cause: – Unknown. Sites: – Typically it affects the terminal part of the ileum. – The colon or any part can be affected.  ID 1 Gross appearance: – It is a segmental (skip) lesion. – The mucosa is swollen and protruded (cobble-stone appearance) with deep linear or fissure ulcers run along the axis of the bowel. – The wall of the intestine is greatly thickened, the lumen is narrow (string sign in x-ray) & there is serosal extension of mesenteric fat.  Crohn’s disease, gross Part of small intestine Cobblestone  ID 1 Microscopic: – There is diffuse infiltration of all layers of the intestinal wall by mononuclear cells with hyperemia and edema. – The characteristic lesion is submucosal tubercles, formed of epithelioid and giant cells without caseation necrosis. – Fibrosis in late stages.  Crohn’s disease, microscopic submucosal tubercles  ID 1 Clinical features: – Recurrent episodes of diarrhea. – Abdominal cramps. – Fever which lasts days to weeks. – Age: two peaks: 10-30, 50-70.  ID 1 Complications of CD: – Intestinal obstruction (due to narrowing). – Perforation of fissuring ulcers, leading to peritonitis or fistula formation. – Mal-absorption syndrome. – Bleeding and anemia. – Mucosal dysplastic changes which increase risk for malignancy five-fold to six-fold.  ID 1 Ulcerative colitis (UC): Definition: it is an inflammatory condition of the colon and rectum, initially it is acute but becomes chronic with periods of remission. The inflammation is limited to the mucosa and submucosa except in severe cases. Cause: – Unknown.  ID 1 Gross appearance: – Continuous lesion in the whole colon. – Congested velvety mucosa. – Shallow ulcers. – Pseudopolyps (intact mucosa). Ulcerative colitis, gross ulcers: red color, intact mucosa: pink  ID 1 Microscopic: – In the acute phase: There is severe congestion of the mucosa and presence of “crypt abscess”. Formation of large mucosal ulcers. – In the chronic phase: Distruction of glandular epithelium. Infiltration by chronic inflammatory cells, mainly plasma cells. Epithelial hyperplasia, & may be dysplasia. Ulcerative colitis, microscopic crypt abscess, infiltration by plasma cells  ID 1 Clinical features: – Attacks of diarrhea with mucus and blood in the stool. – May persist for days or weeks or months. – Then subside to recur after a varying period. – Age: peaks at 20-30.  ID 1 Complications of UC: – Rectal hemorrhage which leads to anemia. – Diarrhea and weight loss. – Perforation (rare). – Malignant change (after 10 ys of pancolitis). – Secondary amyloidosis. – Toxic mega-colon (massive dilatation of the colon with loss of motility).  Comparison between CD & UC Crohn’s disease Ulcerative colitis Site: terminal ileum, Colon only. colon Velvety superficial Gross: cobble stone mucosa, ulcers, and with fissuring ulcers, pseudopolyps. thick wall, narrow lumen. Crypt abscess, ulcers, Microscopic: no tubercles, minimal transmural infl with fibrosis. non caseating tubercles and fibrosis. Occurs (after 10 Malignant change: years). may occur.  ID 1 Acute appendicitis: The most common cause of acute abdomen. Occurs in children and young adults of both sexes. Cause: – Obstruction of the lumen leading to ischemia of the wall and secondary bacterial infection (E coli). – Obstruction is usually due to: fecoliths,  ID 1 Gross appearance: – The appendix is swollen, – Congested, – Fibrin may be seen on the serosal surface. Acute appendicitis, gross  ID 1 Microscopic: – Inflammatory exudate in the lumen. – Infiltration of the wall by acute inflammatory cells (PNLs) especially the muscle layer. – Ulceration and necrosis of mucosa. – Congestion of blood vessels and edema of the wall. – Gangrenous necrosis in severe cases.  Acute appendicitis, microscopic, mucosal inflammation and necrosis  ID 1 Clinical features: – Peri-umbilical pain migrating to the right lower quadrant. – Anorexia. – Vomiting. – Mild fever. – Leucocytosis (> 15000/cmm).  ID 1 Complications of acute appendicitis: – Perforation and peritonitis which may lead to toxemia and death (2%). – Portal pyemia. – Chronic appendicitis.  ID 1 Diverticula of the intestine: Out pouching of the wall of the intestine. It may be: – Congenital (Meckel’s diverticulum) or – Acquired (colonic diverticulosis).  ID 1 Meckel’s diverticulum: – Remnant of the vitelline (omphalo- mesentric) duct. – Rule of 2s: Occurs in 2% of population. Usually diagnosed at 2 years of age. 2 feet (60 cm) from the ileo-cecal valve. 2 cm in length. 2% of carcinoid tumor occur in Meckel diverticulum. Meckel’s diverticulum  ID 1 Complications: – Inflammation (diverticulitis). – Peptic ulcer if there is ectopic gastric mucosa. – Carcinoid tumor. – Intestinal obstruction.  ID 1 Colonic diverticula (acquired): – Occurs in the sigmoid colon in old patients due to chronic constipation. – Gross appearance: Usually multiple, formed of mucosa and submucosa, protruding through weak points in the musculosa. Located at the line of mesenteric attachment to the intestine. Diverticulosis, sigmoid colon sacs bluish in color  ID 1 Complications of colonic diverticulum: – Inflammation. – Fistulous communication with other abdominal viscera. – Perforation and peritonitis.  ID 1 Congenital megacolon (Hirschsprung disease): Genetic disorder leads to lack of ganglion cells in a segment of the colon. There is dilatation of the colon above this part. Gross: – The affected segment (rectum or sigmoid colon) is narrow. – The part above shows dilatation. Microscopic: Absence of ganglion cells in Auerbach’s and Meissner’s plexuses in the submucosa.  Congenital mega colon the affected lower part is narrow  ID 1 Clinical features: – Occurs in infancy. – More in females (4:1). – Constipation – Abdominal distention – Vomiting. Complications: – Enterocolitis (life threatening). – Perforation (rare).