Pathology Flashcards
What are the common diseases of the large bowel? (5)
Diverticular disease Ischaemia Antibiotic reduced colitis Microscopic colitis Radiation colitis
what is diverticular disease?
a condition in which muscle spasm in the colon (lower intestine) in the presence of diverticula causes abdominal pain and disturbance of bowel function without inflammation
What are the causes of diverticular disease?
It is related to a low fibre diet and increased interlumenal pressure
What are the complications of Diverticular disease? (5)
inflammation rupture abscess fistula massive bleeding
What can cause ischaemia of the large bowel? (6)
CVS disease Atrial fibrillation Embolus Atherosclerosis of the mesenteric vessels Shock Vasculitis
Histopathological signs of ischaemic colitis
withering of crypts
pink smudgy lamina propria
fewer chronic inflammatory cells
Complications of ischaemic colitis?
massive bleeding
rupture
stricture
What is colitis?
Inflammation of the lining of the colon
Who gets antibiotic induced colitis?
Patients on broad spectrum antibiotics and is caused by C. Diff
What does the bacteria in antibiotic colitis produce?
Produces toxins which attack the endothelium and epithelium causing mini-infarcts
What are the symptoms of antibiotic induced colitis?
massive diarrhoea and bleeding
what is the treatment for antibiotic induced colitis?
flagyl or vancomycin
May need colectomy if complications arise
How does collagenous colitis present?
watery diarrhoea
What histopathological changes are present in collagenous colitis?
thickened basement membrane i.e. between 2-3 microns
It is associated with intraepithelial inflammatory cells
How is collagenous colitis diagnosed?
A biopsy must be taken and clinical history will include watery diarrhoea and a normal endoscopy
what is the histopathology of lymphocytic colitis?
there are no cjronic changes in the crypts but have raised intraepithelial lymphocytes
How does lymphocytic colitis present?
Watery diarrhoea with no blood and normal mucosa on endoscopy
What is telangiectasia?
a condition characterized by dilatation of the capillaries causing them to appear as small red or purple clusters, often spidery in appearance, on the skin or the surface of an organ.
What would be seen in radiation colitis?
bizarre stroma cells and bizarre vessels
What is a polyp?
A protrusion above an epithelial surface (tumour)
what are the differential diagnoses of a colonic polyp? (4)
adenoma
serrated polyp
polypoid carcinoma
other
Are adenomas benign or malignant?
benign - they don’t invade or metastasise
What is the sequence of events which leads to an adenoma becoming a carcinoma?
Normal mucosa
Dysplastic adenoma
Invasive adenomacarcinoma
Which gene must acquire mutations in the most common pathway for the development of a colorectal carcinoma?
APC
What is the treatment for adenomas?
removal endoscopically or surgically as they are all premalignant
Do all colorectal carcinomas have the same genetic origins?
No - there are separate pathways for inherited tumours and serrated adenomas
What is the treatment for an adenocarcinoma?
Surgery - the colon or rectum is removed and sent to pathology for staging
What is the criteria for Dukes staging A?
Confined by muscularis propria
What is the criteria for Dukes staging B?
Through muscularis propria
What is the criteria for Dukes staging C?
Metastatic to lymph nodes
which parts of the colon would be affected in left sided colorectal cancer?
rectum
sigmoid
descending colon
which parts of the colon would be affected in right sided colorectal cancer?
caecum
ascending colon
what are the common presenting complaints in patients with left sided colorectal cancer?
post rectal blood
altered bowel habits
obstruction
what are the common presenting complaints in patients with right sided colorectal cancer?
anaemia
weight loss
Describe the gross appearance of colorectal cancer
It can be varied - may be polyploid, stricturing and ulcerating
where does colorectal carcinomas spread during local invasion?
mesorectum
peritoneum
other organs
How does colorectal cancer spread through the lymphatics
mesenteric nodes - lie between the layers of the mesentery
where does colorectal cancer spread when it metastasises haematogeniously?
liver
distant sites
Is HNPCC late or early onset
late - usually around 60s
Is FAP late or early onset?
early - usually around 20s
Wha is the inherited mutation in HNPCC?
Mutation in MLH-1, MSH-2, PMS-1 or MSH-6
what is the inherited mutation in FAP?
mutation in the FAP gene
Name two types of inherited colorectal carcinomas
HNPCC and FAP
where do the tumors present in HNPCC?
right side of the colon
where do tumours present in FAP?
throughout the colon
which other carcinomas is HNPCC related to
gastric
endometrial
which other carcinoma is associated with FAP
desmoid tumours
thyroid tumours
what are the three zones of the liver?
Zone 1: Periportal
Zone 2: Mid acing
Zone 3: Pericentral
what kind of necrosis can liver insult produce and is this reversible?
Parenchymal necrosis - heals by resolution
what occurs after insult to hepatocytes?
Inflammation - fibrosis - cirrhosis
What causes acute liver failure?
Viruses
Alcohol
Drugs
Bile duct obstruction
what are the three classifications of jaundice?
Pre-hepatic
Hepatic
Post-hepatic
What are the pre-hepatic causes of jaundice?
Haemolysis
Haemolytic anaemia
unconjugated bilirubin
what are the hepatic causes of jaundice?
Acute liver failure Alcoholic hepatitis Cirrhosis Bile duct loss Pregnancy
what are the post-hepatic causes of jaundice?
congenital biliary atresia
galstone blocked common bile duct
Strictures of the common bile duct
Tumours
what is cirrhosis pathologically defined by?
Bands of fibrosis separating regenerative nodules of hepatocytes
what are the causes of cirrhosis?
Alcohol Hepatitis B Iron overload Gallstones Autoimmune liver disease
What are the complications of cirrhosis?
Portal hypertension
Ascites
Liver failure
what are the clinical presentations of portal hypertension?
Caput medusa
Oesophageal varices
Haemorrhoids
what is the outcome of alcoholic liver disease?
Cirrhosis Portal hypertension Malnutrition Hepatocellular carcinoma Social disintegration
what is the difference between NASH and NAFLD?
NASH is a more serious progression of NAFLD
In what patients does NASH occur?
Diabetics
Obese patients
Hyperlipidaemic patients
