Pathology Flashcards
Causes of acute oesophagitis? Is this common or rare?
RARE
- Corrosive following chemical ingestion (child swallows something they shouldn’t)
- Infective in immunocompromised pts
e. g. candidiasis, herpes, CMV
Causes of chronic oesophagitis? Is this common or rare?
COMMON
Most common cause is reflux oesophagitis
Common complications of reflux?
ulceration (bleeding), stricture (heal by fibrosis, contraction in a hollow organ, you’ll get dysphagia) and Barrett’s oesophagus
Define Barretts oesophagus
Replacement of stratified squamous epithelium by columnar epithelium
Complications of Barretts oesophagus?
This is unstable mucosa and with continuing damage can get dysplasia and therefore carcinoma of the oesophagus
Describe eosinophilic oesophagitis
Rarer cause of oesophagitis
The pH probe is negative for reflux and have high eosinophils
Often in atopic individuals
Are benign oesophageal tumours rare or common? What is the most common type?
These are all extremely rare
The most common of these rare tumours is a squamous papilloma
Two types of malignant oesophageal tumour?
Squamous cell carcinoma and Adenocarcinoma
In adenocarcinoma of the oesophagus what is the key premalignant change?
Barretts oesophagus
Causes of acute gastritis?
This is an irritant chemical injury • Severe burns • Shock • Severe trauma • Head Injury
Causes of chronic gastritis?
- Autoimmune
- Bacterial
- Chemical
Most common type of chronic gastritis is due to …..
H. pylori infection
Rarest type of chronic gastritis is ____ in this there are antibodies to ______
auto-immune
parietal cells and intrinsic factor
Chemical gastritis is the ____ most common cause of chronic gastritis it can be due to ___________
second
Due to NSAIDs, alcohol, bile reflux
Sites of peptic ulceration?
Duodenum (Ist. part), Stomach (junction of body and antrum), Oesophago-gastric Junction
What is ulceration?
Breach in the mucosa
In peptic ulcers the two things that are unbalanced are
acid and mucosal defence
Complications of peptic ulcers?
perforation, penetration, haemorrhage, stenosis and intractable pain
Benign gastric tumours?
- Hyperplastic polyps
- Cystic fundic gland polyps
3 malignant gastric tumours?
Adenocarcinomas, GISTs and Lymphomas
What is a key factor in developing gastric tumours?
H. pylori infection particularly in gastric lymphomas
Describe the two types of gastric adenocarcinomas
Intestinal which is exophytic/ polyploid mass
Diffuse type which expands/infiltrates stomach wall, diffuse type whole stomach is swollen.
Diffuse type is worse cause it usually has no margins so can’t take it out without taking out the whole stomach.
Causes of ischaemia of the small bowel?
- May get a mesenteric arterial occlusion
- Other reasons for ischaemia could be shock, strangulation (loop of small bowel gets stuck somewhere it shouldn’t), drugs and hyper-viscosity of blood
What part of the small bowel wall is most sensitive to hypoxia?
The mucosa as this is the most metabolically active
Explain Meckel’s diverticulum
Is an outpouching or bulge in the lower part of the small intestine. The bulge is congenital (present at birth) and is a leftover of the umbilical cord. Meckel’s diverticulum is the most common congenital defect of the gastrointestinal tract.
Primary tumours of the small bowel are quite rare
Secondary tumours (metastases) are much more common usually from the _______________
Primary tumours of the small bowel are most commonly ___________
colon, ovary or stomach
lymphomas, neuroendocrine tumours and carcinomas
2 conditions associated with increased risk for carcinoma of the small bowel?
Crohn’s and Coeliacs
Pathology of appendicitis?
acute inflammation with neutrophils, mucosal ulceration, serosal congestion, exudate, pus in lumen
Coeliacs is strongly associated with
childhood diabetes
Definition of Crohn’s disease?
- Chronic inflammatory and ulcerating condition of the GI tract that can affect anywhere from the mouth to the anus
- Most common in the terminal ileum and colon
Appearance of crohn’s on endoscopy?
Ulcerated with mucosal cobblestone appearance
Histological appearance of Crohn’s?
Non-caseating granuloma formation, will also be increased inflammatory cells within the lamina propria. Histologically it will all vary throughout the GI tract.
The inflammation is transmural- it extends all the way to the serosa and the disease is discontinuous with skip lesions and normal intervening bowel.
Complications of Crohn’s?
Fistula form as the inflammation extends so far through the bowel wall
Intestinal obstruction
Malabsorption of the ileum is involved
Cancer (smaller risk than in ulcerative colitis)
Definition of ulcerative colitis?
Chronic inflammatory disorder confined to colon and rectum with inflammation in the mucosa and submucosa nearly always involving the rectum
Histological appearance of ulcerative colitis
No granulomas
Ulcers that may be linear
Get swollen curving mucosa forming pseudo-polyps
Complications of ulcerative colitis
Toxic megacolon- the inflammation is so severe that the colon becomes greatly dilated and thinned. There is a high risk of perforation with peritonitis.
Dysplasia and Colonic Cancer increased risk
What are the main distinguishing differences between Crohn’s and ulcerative colitis?
In ulcerative colitis the lesions are continuous but only in the mucosa. In Crohn’s there are skip lesions that are transmural.
In ulcerative colitis the inflammation tends to begin in the rectum and move up whereas crohn’s has more ill involvement and not always rectal involvement,
Ulcerative colitis has granular, ulcerated mucosa with no fissuring and crowns has discretely ulcerated mucosa with a cobblestone appearance and fissuring.
Ulcerative colitis causes muscular shortening of the colon whereas crohns is fibrous with strictures often forming
In ulcerative colitis, fistulae are rare but malignancy more common. Opposite for crohns
In ulcerative colitis anal lesions are much less common.
What is a polyp?
A protrusion above an epithelial surface
Why must all adenomas of the colon be removed?
They are premalignant
Duke’s staging of colorectal carcinomas?
Dukes A: Confined by muscularis propria
Dukes B: Through muscularis propria/ externa
Dukes C: Metastatic to lymph nodes
Patterns of spread of colorectal cancers?
Local invasion: Mesorectum, Peritoneum, Other organs
Lymphatic spread: Mesenteric nodes
Haematogenous: Liver, distant sites
Differences between left and right sided colorectal presentations?
75% Left sided (rectum, sigmoid, descending)
p/c: Blood PR, Altered bowel habit, Obstruction
25% Right sided (Caecum, Ascending)
p/c: Anaemia, Weight loss
Where is diverticular disease most commonly found?
The sigmoid colon
What is diverticular disease related to?
A low fibre diet and increased intraluminal pressure
Complications of diverticular disease?
inflammation, rupture, abscess, fistula and massive bleeding
Histology of ischaemic colitis?
withering of crypts, pink smudgy lamina propria and fewer chronic inflammatory cells
What is Antibiotic Induced Pseuodomembranous Colitis and what is it treated with?
Type of colitis that occurs with patients infected with C difficile due to broad spectrum antibiotics
Treated with vancomycin
Explain microscopic colitis and the types
- Two subsets of diseases that are often overlooked due to normal findings on endoscopy
- Patients present with watery diarrhoea
- Collagenous colitis results in a thickened basement membrane with a subepithelial collagenous band. Plasma cells are increased in number in the lamina propria
- Lymphocytic colitis results in a marked increase in intraepithelial lymphocytes akin to those seen in coeliac disease
- There is no chronic architectural changes to the crypts in either
Three main types of jaundice?
Pre hepatic, hepatic and post hepatic
Describe pre-hepatic jaundice
This is due to increased red blood cell destruction, this may be caused by haemolytic anaemia. The increase is in unconjugated bilirubin.
Describe hepatic jaundice
This is due to liver failure e.g. hepatitis meaning you cannot conjugate bilirubin- the rise is therefore in unconjugated bilirubin.
Describe post hepatic jaundice
This is caused by failure to excrete conjugated bilirubin. e.g. if a stone was obstructing the common bile duct or there was a carcinoma at the head of the pancreas. The rise is therefore in conjugated bilirubin.
Hepatocytes in what zone of the liver acinus are most susceptible to injury?
Zone 3
Examples of other viruses that can affect the liver but also affect other tissues?
Yellow fever
Herpes viruses- Epstein Barr, cytomegalovirus, herpes simplex.
Cosackie A and B
Lassa Fever
What is fulminant hepatitis?
Rare syndrome of massive necrosis of liver parenchyma and a decrease in liver size (acute yellow atrophy) that usually occurs after infection with certain hepatitis viruses, exposure to toxic agents, or drug-induced injury.
What is acute yellow atrophy of the liver?
Loss of substance in liver with remaining liver tissue turning an opaque yellowish colour without markings and largely necrotic. There is bile duct hyperplasia
What is the definition of chronic hepatitis?
Inflammation of the liver which lasts for more than 6 months
What are the four main causes of chronic hepatitis?
1) Persistent viral infection- B, D or C
2) Auto-immune hepatitis- especially in young women
3) Drugs
4) Metabolic disorders- AAT deficiency and Wilsons
What is cirrhosis defined as?
A diffuse process (ie the whole liver is affected) characterised by fibrosis and conversion of the liver architecture into abnormal nodules.
Cellular mechanism of liver fibrosis?
Hepatic stellate/ Ito cells (fat storing) found in the space of Disse are activated and transformed into myofibroblasq-like cells under the influence of cytokines such as TGF-alpha, PDGF and TGF-beta. These activated cells synthesis collagen leading to fibrosis.
3 major complications of cirrhosis?
Hepatocellular failure
Portal hypertension
Hepatocellular carcinoma
3 main forms of alcoholic liver disease? Which are reversible?
Fatty liver (most individuals and is reversible on withdrawal) Alcoholic Hepatitis (mainly reversible) Alcoholic Cirrhosis (irreversible)
Describe alcoholic fatty liver
This occurs in most heavy drinkers even after a single episode of heavy intake. Fat accumulates in hepatocytes due to abnormalities in the intermediate metabolism of lipids and carbohydrates. Known as steatosis (abnormal retention of lipids).
Describe alcoholic hepatitis
This happens in heavy drinkers and get liver swelling, liver cell necrosis, neutrophil polymorph infiltration, pericellular fibrosis.
Describe Non-alcoholic fatty liver disease (NAFLD)?
This is a fatty liver condition that develops in patients who do not drink alcohol. The liver may show steatosis, steatohepatitis or cirrhosis, the changes are often less marked than those seen with alcohol. It is associated with metabolic syndromes of obesity, insulin resistance, dyslipidaemia or hypertension.
Difference between NASH and NAFLD?
NAFLD is fatty liver but NASH has inflammation and liver cell damage
3 examples of autoimmune liver diseases?
Primary biliary cirrhosis
Primary sclerosis cholangitis
Autoimmune hepatitis
What is primary biliary cirrhosis?
A chronic autoimmune disorder than mainly affects middle-aged women. There is destruction of intra-hepatic bile ducts leading to scarring and eventually cirrhosis. Most patients have anti-mitochondrial antibodies in their serum and there can be an overlap with chronic auto-immune hepatitis.
What is primary sclerosing cholangitis?
This is an autoimmune disease that attacks the bile ducts, both intra and extra hepatic. It is usually men that are affected and there is a strong association with ulcerative colitis.
What is chronic auto-immune hepatitis?
- Commoner in females
- Associated with other AI diseases
- Chronic hepatitis pattern
- Numerous plasma cells
- Autoantibodies to smooth muscle, nuclear or LKM, raised IgG
- May have triggers, including some drugs
3 liver storage diseases?
1) Haemochromatosis- too much iron
2) Wilson’s disease- too much copper
3) AAT deficiency- protease inbalance- destruction of liver and lung tissue
Someone presents with diabetes and funny bronze colour to skin think?
Haemochromatosis
Child presents with liver disease and gold ring around eye think?
Wilsons disease
Someone presents with emphysema and liver disease think?
AAT Deficiency
The most common tumours of the liver are?
Secondary metastases commonly from GI tract, lung and breast.
What is the most common primary malignancy of the liver? What is it associated with?
Hepatocellular carcinoma
Viral Hepatitis and Cirrhosis
What is Cholecystitis?
inflammation of the gallbladder, it is usually associated with gall stones
What is Cholangitis?
inflammation of the bile duct system
What is colic?
Severe pain in the abdomen caused by wind or obstruction
What is Cholelithiasis?
The formation of gall stones
Gallstones form when there is an imbalance between the ________1_____________
Cholesterol stones are associated with _____2______ in the bile- associated with ____________3____________
Bile pigment stones are associated with _______________4________________
Most gall stones are ______5_______
1) ratio of cholesterol to bile salts disrupting micelle formation
2) excessive cholesterol
3) diabetes, obesity, females and genetic factors
4) chronic haemolysis with excess bilirubin production- the excess bilirubin cannot be dissolved into the bile salts
5) a mixture of both
Describe acute cholecystitis
- Occurs when gallstones are obstructing outflow of bile
- The gall bladder Initially sterile, then becomes infected
- May cause empyema, rupture, peritonitis
Describe chronic cholecystitis
- May develop insidiously or after bouts of acute cholecystitis
- In the majority of cases the symptoms are of vague indigestion, intolerance of fatty foods and vague right hypochondrial pain
- The gallbladder is packed with gall stones and the wall is thickened and fibrosed
What happens when there are stones in the common bile duct?
This is a complication of gall stones and this can cause obstructive jaundice as well as ascending infection (cholangitis) and acute pancreatitis
What is gallstone ileus?
Rare form of small bowel obstruction- a stone may ulcerate through the gallbladder into the intestine and cause obstruction
Describe carcinoma of the gallbladder? What is it associated with?
- This is rare but almost always associated with gallstones
* Most cases are adenocarcinomas which spread directly to the liver
What is cholangiocarcinoma? What is it associated with?
Carcinoma of the bile ducts. This is associated with ulcerative colitis and primary sclerosing cholangitis and presents with obstructive jaundice
What does acute pancreatitis present with? What is it associated with?
- This presents with sudden acute onset of abdominal pain, patients may be severely shocked and will have elevated serum amylase
- Main causes are gall stones and alcohol
Initiating event of acute pancreatitis caused by gall stones?
Bile reflux is the initiating event, stones can pass down the bile duct and block the ampulla of vater causing reflux of bile along the pancreatic duct
What happens in acute pancreatitis?
- The loss of the protective sphincter also autodigestion of the pancreatic acini.
- There is release of lytic pancreatic enzymes proteases and lipases
- Intra- and peripancreatic fat necrosis by lipases
- Tissue destruction and haemorrhage by proteases
Main complications of acute pancreatitis?
Shock and pancreatic pseuodcyst
Who does chronic pancreatitis predominantly effect? What happens?
- This predominantly affects alcoholics.
* There is replacement of pancreas by chronic inflammation and scar tissue and destruction of exocrine acini and islets
Where do the majority of carcinomas of the pancreas occur?
In the head of the pancreas
What will carcinomas of the head of the pancreas often present with? Why?
Carcinomas in the head will often obstruct the bile duct and therefore present with jaundice.
