5. GI Pathology Flashcards
The oesophagus is mostly lined by what cell type?
How does this change as you go down the oesophagus?
Stratified squamous epithelium
Changes to Columnar epithelium at the squamo-columnar junction (usually 40cm from the incisor teeth, below the diaphragm)
What is the most common cause of oesophagitis?
Chemical causes:
- Ingestion of corrosive substance - accidental/intentional
- Reflux of gastric contents - reflux oesophagitis (heartburn)
What is the difference between a ‘Sliding hiatus hernia’ and a ‘Paraoesophageal hiatus hernia’?
Sliding = part of the stomach slides up into the chest with the oesophagus. Gives reflux symptoms.
Paraoesophageal = part of the stomach herniates through the diaphragm to sit along side the oesophagus. Strangulation of this hernia can occur. (less common, more serious)
What is Barrett’s oesophagus and what is the cause?
What are the risk factors for it?
Barrett’s oesophagus = change in mucosal lining from stratified squamous to columnar (same as intestines), this increases your risk of developing an oesophageal adenocarcinoma.
Cause = long standing gastro-oesophageal reflux
Risk factors = Male, Caucasian, Overweight
Barrett’s oesophagus can develop into what?
Oesophageal adenocarcinoma
Barrett’s > low grade dysplasia > high grade dysplasia > adenocarcinoma
Oesophageal carcinoma is the 8th most common cancer in the world.
What are the 2 main histological sub-types?
- Squamous cell carcinoma
2. Adenocarcinoma
The TNM system is a staging system used to classify the extent of spread of a tumour.
What does the T, N, M stand for?
pT = how far has the primary Tumour invaded
pN = number of regional lymph Nodes
pM = is there a distant Metastasis
What bacterial infection can cause acute gastritis which develops into chronic gastritis if left untreated?
Where in the stomach is it most commonly found?
Helicobacter pylori
Antrum
What is the cellular order in GI starting with mucosa?
Mucosa > lamina propria > sub mucosa > muscularis propria
Gastric adenocarcinoma is the 5th most common cancer in the world.
What are the 2 subtypes?
- Diffuse type - Linitis plastica
(poorly differentiated, H pylori NOT important) - Intestinal type
(well/moderately differentiated, H pylori important)
Coeliac disease is caused by a reaction to …………. which induces IL-15 secretion by epithelial cells that cause CD8+ cells to proliferate and kill enterocytes.
Gliadin
alcohol soluble component of gluten
How is coeliac disease diagnosed?
Serology test followed by a biopsy (gold standard)
What are the histological features of coeliac disease?
- Villous atrophy
- Increased IELs (intraepithelial lymphocytes)
- Crypt elongation
- Increased lamina propria inflammation
Type of large bowel diverticula which outpouches through the mucosa and submucosa of the bowel wall.
Acquired (‘false/pseudo’) diverticulum
Type of bowel diverticula composed of ALL layers of the bowel wall e.g. Meckel’s diverticulum.
True (‘congenital’) diverticulum
Where is the most common site of diverticulosis?
Sigmoid colon
sigmoid colon is one of the most muscular parts of the colon so can generate a lot of pressure within the lumen
What is colitis?
Inflammation of colon
Inflammatory bowel disease affecting only the rectum and/or sigmoid colon
Ulcerative colitis
Inflammatory bowel disease presenting with patchy distribution and the formation of a granuloma.
Crohn’s disease
Where do most cases of ischemic colitis affect?
Left colon
Most common type of polyp in the colo-rectum, usually have no clinical significance.
Hyperplastic polyp
Most common type of polyp in children.
Juvenile polyp
What gene mutation causes Peutz-Jeghers syndrome?
STK11 gene (Chr 19)
Common type of neoplastic polyp arising from the epithelium.
Adenoma
Lynch syndrome (HNPCC) is a form of hereditary colo-rectal cancer syndrome. What is is caused by?
Mutation in the DNA mismatch repair genes.
Where is the most common distant metastasis site of colorectal cancer?
Liver
followed by lungs
Angular Cheilitis is acute/chronic inflammation of the skin at the corners of the mouth.
What bacterial infection causes this?
How is it treated?
Candida albicans
(less so S. Aureus)
Treatment = topical antifungals/antibiotics
Oral Hairy Leucoplakia are white patches on the lateral tongue with a ‘hairy’ appearance.
What virus causes this?
Epstein Barr virus
(also causes glandular fever)`
Peritonsillar abscess = unilateral swelling of tonsils
What bacteria causes this?
Streptococcus pyogenes (group A streptococcus)
Acute suppurative parotitis = infection of parotid glands
What bacteria almost always causes this?
Staphylococcus aureus
An infection of the submandibular space.
Ludwig’s angina
A condition involving inflammation of the GI tract that is usually induced by chemotherapy.
Mucositis = inflammation of mucous membranes lining the GI tract
Oesophageal rupture is known as what syndrome?
Boerhaave syndrome
The enzyme secreted by Helicobacter pylori to neutralise stomach acid and survive.
Bacterial urease
Cholangitis = inflammation/blockage of the common bile duct
The classic presentation of this is Charcot’s triad, what is this?
- Fever
- Abdominal pain
- Jaundice
Infection of the gall bladder itself.
Cholecystitis
What bacteria causes Whipple’s disease and what are the 4 classical symptoms?
Tropheryma Whipplei
- Joint pain
- Chronic diarrhoea
- Malabsorption
- Weight loss
Where is the most common GI site for Tuberculosis?
Ileocecal
Meckel’s diverticulum is an out pouching of the small intestine.
What is it a remnant of?
Yolk sac
What are the different types of gastroenteritis and give an example of a cause for each.
Foodborne gastroenteritis =
- Staphylococcus aureus
- Clostridium perfringens
- Escherichia coli
- Salmonella spp (gram -)
- Shigella spp (gram -)
- Campylobacter spp
Non-foodborne gastroenteritis =
- Salmonella spp (gram -)
- Campylobacter spp
- Escherichia coli
Viral gastroenteritis =
- Rotaviruses
- Noroviruses
Waterborne gastroenteritis =
- Giarda lamblia
- Vibrio cholerae
Antibiotic associated diarrhoea =
1. Clostridium difficile
Microorganism commonly associated with chronic gastritis?
Helicobacter pylori
Main risk factor for hepatocellular carcinoma?
Cirrhosis
Condition in which there is increased susceptibility for developing colorectal cancer due to mutations in DNA mismatch repair genes?
Lynch syndrome
Inherited disorder of copper metabolism that results in increased urine copper levels?
Wilson’s disease
Condition in which there are IgA antibodies to tissue transglutaminase (TTG) with villous atrophy of duodenum?
Coeliac disease
What type of epithelium lines the normal oesophagus?
Stratified squamous
Liver tumour that arises in the bile ducts?
Cholangiocarcinoma
Condition that presents with a sudden onset of severe abdominal pain radiating to the back and a raised serum amylase?
Acute pancreatitis
Condition in which the squamous mucosa of the oesophagus is replaced by columnar mucosa?
Barrett’s oesophagus
A glucose polysaccharide that serves as a form of energy storage?
Glycogen
An enzyme that can be tested for in blood that helps the diagnosis of Wilson’s disease?
Caeruloplasmin
The presence of fatty change associated with inflammation in the liver?
Steatohepatitis
In which part of the large bowel are diverticulae most often seen?
Sigmoid
The conversion of Glycogen to Glucose in the body is termed as …….?
Glycogenolysis
Term for bilateral infection of the submandibular space?
Ludwig’s angina
What is the most frequent site for colon cancer distant metastasis?
Liver
What type of chronic inflammatory bowel disease commonly affects the anus?
Crohn’s disease
Name the fungus responsible for oral thrush?
Candida
Liver enzyme that is commonly elevated in cholestasis?
Alkaline phosphatase
A common cause of diarrhoea in infants and young children?
Rotavirus
A common pancreatic neuroendocrine tumour that can result in hypoglycaemia?
Insulinoma
Most common benign epithelial polyp in the lower GI tract?
Adenoma
Sign of chronic liver disease?
Spider naevi
Cholecystitis occurs when there is an infection of which anatomical structure?
Gall bladder
The clinical effect of hyperbilirubinaemia?
Jaundice
