PATH375 Gastrointestinal, Liver, Biliary Tract, Pancreas

Complications of dental caries

Pulpitis, periapical abscess, periapical granuloma, radicular cyst

Periodontitis

Inflammation of the periodontal pocket from colonization of bacteria

Stomatitis

Inflammation of the mouth mucosa membrane

Causes of infectious stomatitis

Virus (herpes; cold sores), bacteria, fungi (candida)

Causes of non-infectious stomatitis

Aphthous ulcers (canker sores), nutritional deficiencies (iron, B12, folic acid), immunologic/allergic

Most common malignant oral neoplasms

Squamous cell carcinomas (>95%)

Leukoplakia

Persistent white patch

Erythroplakia

Persistent red patch

Sialadentitis

Inflammation of salivary glands

Infectious causes of sialadentitis

Bacterial (S. aureus) and viral (mumps)

Non-infectious causes of sialadentitis

Sjögren's syndrome (inflammation of salivary and lacrimal glands, manifests in dry mouth and eyes), sialolithiasis (stones)

Benign neoplasm of the salivary gland

Pleomorphic adenoma

Malignant neoplasm of the salivary gland

Mucoepidermoid carcinoma

Hiatus hernia

Displacement of a portion of the stomach above the diaphragm

Sliding hernia (95%)

"Sliding" of the gastroesophageal junction and cardia of the stomach upwards

Paraesophageal hernia (5%)

Stomach protruding upward and forms a pocket beside the esophagus

Achalasia

Esophageal obstruction resulting in increased resting tone of the lower esophageal sphincter (LES), causing difficulty swallowing (dysphagia)

Esophagitis

Inflammation of the esophageal epithelial lining

Causes of esophagitis

Infectious (viral herpes, fungal Candida), reflux of gastric acid (GERD), chemical causes

Gastroesophageal Reflux Disease (GERD)

Reflux of gastric contents into the esophagus due to the relaxed tone of the LES, allowing reflux of acid

Barrett esophagus

Presence of metaplastic (intestinal type) epithelium in the lower esophagus; risk of progression to dysplasia and adenocarcinoma

Esophageal varices

Dilation of the submucosal veins of the distal esophagus due to portal hypertension secondary to hepatic cirrhosis

Malignant esophageal neoplasms

Squamous cell carcinoma (upper mid esophagus, squamous lining), adenocarcinoma (distal, glandular lining)

Signs/symptoms of malignant esophageal neoplasms

Pain on swallowing (odynophagia), difficulty swallowing, bleeding

Acute gastritis

Acute inflammation of the mucosal lining of the stomach that can cause erosions or ulcers

Causes of acute gastritis

Stress, drugs (aspirin), and alcohol

Chronic gastritis

Chronic inflammation of the mucosa with acute exacerbations; associated with H. pylori and autoimmune gastritis

Helicobacter pylori infection is associated with

Increased incidence of gastric adenocarcinomas and lymphomas (MALT lymphomas)

Autoimmune gastritis

Autoimmune destruction of parietal cells; associated with megaloblastic anemia and gastric adenocarcinoma

Peptic ulcer disease

Ulceration of the gastric or duodenal mucosa

Factors of peptic ulcer disease

Helicobacter pylori, reduced mucosal barrier resistance (shock, stress), drugs (NSAIDs, aspirins, steroids)

Complications of peptic ulcer disease

Hemorrhage (melena, iron deficiency anemia, hematemesis), perforation (peritonitis), penetration (ulcer penetrates into pancreas), scarring (stenosis causing obstruction)

Classification of gastric adenocarcinoma by gross appearance

Polypoid, fungating, ulcerating, diffuse

Classification of gastric adenocarcinoma by histological appearance

Intestinal type, signet cell

Metastasis of gastric adenocarcinoma

Lymph nodes (Virchow node, supraclavicular), bilateral ovarian involvement (Krukenberg tumor)

Meckel's diverticulum

Developmental disorder of the small bowel due to persistence of the omphalomesenteric (vitelline) duct

Rule of 2's (Meckel's diverticulum)

2% of population, 2% develop symptoms, presentation before 2 years of age, 2 ft from ileocecal valve, 2 inches long, 2 types of ectopic tissue (gastric and pancreatic)

Classification of malabsorption

Inadequate intraluminal digestion (insufficiency of gastric juices and exocrine pancreas), primary mucosal absorptive defect (celiac sprue), impeded transport of nutrients (congestive heart failure)

Celiac Disease (Gluten-sensitive enteropathy)

Damage to the small bowel mucosa due to a hypersensitivity reaction to gluten (a protein present in wheat)

Inflammatory Bowel Disease (IBD)

Term used for 2 diseases characterized by recurrent inflammation of the intestines with chronic, unpredictable course

Crohn's disease involves

Right colon and terminal ileum; rectum usually spared while anus is usually involved

Characteristics of Crohn's disease

Skip lesions (discontinuous inflammation), transmural inflammation, granulomas

Complications of Crohn's disease

Fissures, strictures/obstruction, fistulas, adhesions

Ulcerative colitis involves

Left colon; rectum is usually involved while anus is usually spared

Characteristics of ulcerative colitis

Confluent involvement (no skip lesions), inflammation confined to the mucosa

Complications of ulcerative colitis

Toxic megacolon and dysplasia (higher risk than Crohn's disease)

Hirschsprung's disease

Congenital absence of colonic ganglion cells resulting in a portion of colon (usually rectum and sigmoid colon) with no peristalsis

Diverticular disease

Outpouchings of colonic mucosa (pseudodiverticulum; false diverticula) common in the sigmoid colon; generally in the elderly

Complications of diverticular disease

Pericolonic abscess, peritonitis, colonic stenosis (obstruction)

Hyperplastic polyp in the large bowel

Most common colonic polyp; no malignant potential

Hamartomatous polyp in the large bowel

Benign, disorganized growth of cells and tissue normally found in the site where growth occurs; occurs in children and manifests in Peutz-Jeghers syndrome

Peutz-Jeghers syndrome

Autosomal dominant with multiple hamartomatous polyps and pigmented lesions on lips and peri-oral skin; causes increased risk of malignancies in colon (also upper GI tract, breast, ovaries, testes)

Adenomatous polyps in the large bowel

Benign epithelial neoplasms (tubular, villous, tubulovillous) with increased risk of carcinoma

Age group at risk for developing colonic carcinoma

Peak incidence at 60-80 years old; rare <40 years old unless with a predisposing condition

Risk factors of colonic carcinoma

Inflammatory Bowel Disease and Familial Adenomatous Polyposis

Colonic carcinoma occurrence

Adenocarcinoma in the distal colon

Appendicitis

Acute bacterial infection of the appendix secondary to luminal obstruction (fecalith, lymphoid hyperplasia, pinworms)

Characteristics of appendicitis

Abdominal pain (McBurney's point, rebound tenderness), systemic features, and leukocytosis

The most common neoplasm in the appendix

Carcinoid (neuroendocrine tumor), but adenocarcinomas also occur

Jaundice

Yellow discoloration of skin and mucosa caused by hyperbilirubinemia

Classification of jaundice

Prehepatic (hemolysis of red blood cells), hepatic (cirrhosis), posthepatic (cancer at head of pancreas)

Process of bilirubin production

Heme loses iron → transformed into bilirubin → binds to albumin → transported to liver → bound to glucuronide → excreted into bile → gallbladder → bile ducts → duodenum

Urobilinogen

Bilirubin not used in digestion of dietary fats; converted by bacteria to urobilinogen, which is then reabsorbed/recirculated to liver or excreted in urine

Hepatitis

Inflammation of the liver parenchyma with both infectious and non-infectious causes

Drug/toxin causes of non-infectious hepatitis

Acetaminophen (dose-related necrosis), alcohol (fatty liver/steatosis, alcoholic hepatitis with acute inflammation and fibrosis, and cirrhosis)

Metabolic causes of non-infectious hepatitis

Hemochromatosis (autosomal recessive disorder of iron metabolism causing deposition in organs), Wilson's disease (autosomal recessive disorder of copper metabolism causing deposition in organs), alpha 1 antitrypsin deficiency (autosomal recessive disorder causing emphysema and cirrhosis)

Causes of infectious hepatitis

Usually due to 5 hepatotropic viruses (Hepatitis A, B, C, D, E)

Hepatitis A

Fecal oral transmission (contaminated food/drinks); no chronic state and favorable prognosis

Transmission of Hepatitis B, C, and D

Vertical transmission (mother to baby), sexual transmission, Intravenous Drug Use (IVDU)

Associated risks of Hepatitis B

Increased incidence of hepatocellular carcinoma, 5-10% progress to chronic hepatitis, 2/3 asymptomatic and 1/3 symptomatic

Associated risks of Hepatitis C

Increased incidence of hepatocellular carcinoma, 50-70% progress to chronic hepatitis, NO VACCINE

Associated risks of Hepatitis D

Greater likelihood of acute liver failure (fulminant hepatitis); requires coinfection with hepatitis B

Hepatitis E

Fecal oral transmission (contaminated food/drinks); no chronic state but poor prognosis in pregnant patients

Hepatic abscess

Abscesses may form in liver parenchyma; caused by bacteria or by an ameba (a parasite)

Hydatid disease

Disease of various organs caused by a parasite (Echinococcus) and characterized by formation of cysts

Schistosomiasis

Liver disease results from schistosome (a parasite) depositing eggs in branches of portal vein

Ascariasis

Liver disease resulting from obstruction of bile ducts by the parasite

Primary sclerosing cholangitis (PSC)

Destruction of intrahepatic and extrahepatic bile ducts by lymphocytes and macrophages with increased incidence of cholangiocarcinoma

Primary biliary cholangitis (PBC)

Immune-mediated (possibly T-cell) destruction of small intrahepatic bile ducts and eventual cirrhosis (develops over 10-15 years)

Auto-immune hepatitis (AIH)

Chronic hepatitis in young females characterized by presence of autoantibodies to specific antigens

Cirrhosis

End-stage liver disease characterized by fibrosis and regenerative nodules, causing surface of liver to be nodular and fibrotic

Causes of cirrhosis

Alcohol, drugs, hepatitis (AIH, HBV, and HCV), metabolic and hereditary disorders, PSC and PBC

Complications of cirrhosis

Jaundice, bleeding, edema, ascites, pleural effusion, gynecomastia, encephalopathy, hematemesis, melena, portal hypertension, esophageal varices, splenomegaly

Benign neoplasm in the liver

Cavernous hemangioma (neoplasm of endothelial blood vessel origin; most common), hepatocellular adenoma (neoplasm of hepatocyte origin)

Risk factors of hepatocellular carcinoma (HCC)

Cirrhosis, HBV, HCV, hemochromatosis, and alpha 1 antitrypsin deficiency

Tumor marker of hepatocellular carcinoma (HCC)

AFP (alpha fetal protein)

Metastatic malignancy in liver

Most common malignancy of the liver; usual primary sites being gastrointestinal tract, lung, and breast

Types of Cholelithiasis (gallstones)

Cholesterol stones, pigment stones, mixed stones

Complications of cholelithiasis

Cholecystitis, obstructive jaundice, ascending cholangitis, gallstone ileus (obstruction of bowel caused by impaction of gallstones)

Acute pancreatitis

Acute inflammation with tissue necrosis due to release of pancreatic enzymes

Common causes of acute pancreatitis

Alcohol and gallstones (responsible for 80% of cases)

Complications of acute pancreatitis

Abscess, pseudocyst, peritonitis, chronic pancreatitis, diabetes

Chronic pancreatitis

Persistence of inflammation after original inciting agent is removed, with progressive and irreversible fibrosis which may result in exocrine or endocrine insufficiency

Pancreatic carcinoma

Common in patients with jaundice in the form of adenocarcinoma arising from duct epithelial cells (poor prognosis)