GIT Pathology PDF

Pathology of GIT Associate prof. of Pathology Dr.Marwa Shakweer ASU/BUC  ILOs Define Gastroesophageal Reflux disease and explain its pathogenesis, clinical presentations Explain pathogenesis of peptic ulcer List manifestations of peptic ulcer Explai...

Pathology of GIT Associate prof. of Pathology Dr.Marwa Shakweer ASU/BUC  ILOs Define Gastroesophageal Reflux disease and explain its pathogenesis, clinical presentations Explain pathogenesis of peptic ulcer List manifestations of peptic ulcer Explain pathogenesis and clinical presentations of colon cancer MM.Shakweer  Gastroesophageal reflux disease (GERD) Def: Most common cause of esophagitis Due to reflux of gastric or duodenal contents into lower esophagus Esophageal squamous epithelium is prone to injury from acid MM.Shakweer  Etiology of GERD Due to decreased efficiency of esophageal antireflux mechanisms, especially lower esophageal tone, the primary barrier to reflux Increased risk with alcohol and other central nervous system depressants Other risk factors are delayed gastric emptying, hypothyroidism, pregnancy, sliding hiatal hernia, tobacco MM.Shakweer  Clinical features of GERD Symptoms: heartburn, dysphagia; pain may be mistaken for myocardial infarction Endoscopy: linear ulcers at distal esophagus, often with exudate; also erythema or edema; normal in 50 - 60% of symptomatic patients - thus biopsy required if clinically suggestive of reflux esophagitis even if normal endoscopy MM.Shakweer  Diagnosis of GERD Clinical (heartburn, regurgitation), endoscopic Histologic examination MM.Shakweer  Histopathology of GERD Basal cell hyperplasia Intraepithelial inflammatory cells Barrett’s esophagus: transformation of squamous epithelium into columner epithelium: may transform to cancer MM.Shakweer  Treatment Motility promoting drugs, H2 receptor antagonists, proton pump inhibitors, surgery to reduce hiatal hernia MM.Shakweer  Peptic ulcer (PU) Def: erosion of GI epithelium due to acid- peptic juices which is chronic and usually solitary MM.Shakweer  Causes of PU Mucosal injury due to Helicobacter pylori infection, NSAID use, Zollinger-Ellison syndrome (multiple peptic ulcerations in stomach, duodenum and jejunum due to excess gastrin secretion by a tumor), Alcohol, smoking, corticosteroids use may exacerbate peptic ulcer disease and impair healing MM.Shakweer  Pathophysiology H. pylori related ulcers: Produces urease (to protect it from acid), protease (breaks down glycoproteins in gastric mucus), phospholipase (damages epithelial cells, may release leukotrienes) Attracts neutrophils that produce myeloperoxidase leading to destruction of epithelial cells NSAIDs induced PU: The gastric mucosa protects itself from gastric acid with a layer of mucus, the secretion of which is stimulated by certain prostaglandins. NSAIDs block the function of cyclooxygenase 1 (COX-1), which is essential for the production of these prostaglandins. MM.Shakweer  Common sites Duodenum, antrum, lesser curvature, GE junction, margins of gastrojejunostomy,, lower esophagus 98% in stomach or duodenum Duodenum:stomach 4:1 Gastric ulcers on greater curvature or not in antrum are more likely to be related to NSAID use, ulceration may also be caused by tumors, infections (other than H. pylori) especially in immunocompromised patients MM.Shakweer  Clinical picture abdominal pain, classically epigastric, strongly correlated with mealtimes. In case of duodenal ulcers, the pain appears about three hours after taking a meal and wakes the person from sleep; nausea and copious vomiting; weight gain, in duodenal ulcer, as the pain is relieved by eating; hematemesis (vomiting of blood); this can occur due to bleeding directly from a gastric ulcer or from damage to the esophagus from severe/continuing vomiting. melena (tarry, foul-smelling feces due to presence of oxidized iron from hemoglobin); MM.Shakweer  Treatment of PU Antibiotics if H. pylori induced promote healing of ulcers and reduce greatly recurrences, proton pump inhibitors, discontinuation of NSAIDS and corticosteroids, smoking cessation MM.Shakweer  Colon cancer Def: Primary epithelial malignancy arising in the colorectum Second or third most common cancer and cause of cancer deaths in men and in women 98% of colonic cancers are adenocarcinomas More common in men than women Most common cause of cancer related death among nonsmokers Peak age 60 - 79 years < 20% of cases occur before age 50 Rare before age 40 except in patients with a predisposition syndrome MM.Shakweer  Sites May arise anywhere in the colorectum, but sigmoid colon and rectum are most common sites MM.Shakweer  Etiology Risk factors: older age, obesity, physical inactivity, alcohol consumption, inflammatory bowel disease, family history of colorectal neoplasia Polyposis syndromes: familial adenomatous polyposis and variants (APC gene), Dietary risk factors: low vegetable fiber, increased beef consumption, decreased vitamins A / C / E – Low fiber prolongs transit time (toxic oxidative byproducts are in longer contact with colonic mucosa) and alters bacterial flora – Beef consumption enhances synthesis of bile acids by liver, which may be converted into carcinogens by bile acids MM.Shakweer  Clinical features Screening: colonoscopy, occult blood test Symptoms: – Right sided carcinomas cause anemia (due to blood loss) and vague abdominal pain – Left sided carcinomas cause change in bowel habits (diarrhea or constipation) and rectal bleeding – Some patients may be asymptomatic, and tumors are detected by screening, especially if lesion is early Metastases: – 60% of patients have lymph node or distant metastases at diagnosis – Most common metastatic sites are regional lymph nodes, liver, peritoneum, lung, ovaries Prognosis: – 5 year survival is 40% - 60% – Most recurrences are within 2 years MM.Shakweer  Treatment Surgical excision followed by chemotherapy ± Radiotherapy MM.Shakweer  References Weisenberg E. Reflux esophagitis / gastroesophageal reflux disease / GERD. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/esophagusr eflux.html. Accessed March 22nd, 2020. Weisenberg E. Peptic ulcer disease. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stomachPU D.html. Accessed March 22nd, 2020. Gonzalez R. Colon carcinoma - General. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumor carcinomageneral.html. Accessed March 22nd, 2020. MM.Shakweer