Pancreatic pathology Flashcards
pancreas is located in the
deep retroperineum
which part of the pancreas is dissected during surgery
the neck
Functions of the pancreas: EXOCRINE
exocrine is 85% of pancreas
glands secrete chemicals into the ducts that then reach the duodenum
Trypsin, lipase and amylase secreted.
Conversion of trypsinogen to trypsin occurs at the duodenum
Functions of the pancreas:
ENDOCRINE
Islets of Langerhans
Secrete peptide hormones into blood e.g. insulin and glucagon
1-2% of the pancreas
What is pancreatitis?
Inflammation of the pancreas
Caused by injury to the exocrine parenchyma
What is the difference between acute and chronic pancreatitis?
Acute - the gland reverts to normal if underlying cause is removed
Chronic - irreversible loss of the pancreatic tissue
Aetiology of acute pancreatitis
50% of cases are caused by gallstones
25% of cases are caused by alcohol
Rare causes include:
- vascular insufficiency
- viral infections like mumps
- hypercalcaemia
- ERCP
- Inherited causes
Hereditary pancreatitis - what is it?
Recurrent attacks of severe pancreatitis
Usually beginning in childhood
Caused by mutations of:
PRSS1 - Aut. dominant
SPINK 1 gene - Aut. recessive
Clinical features of acute pancreatitis
Emergency requiring admission to hospital
Sudden onset of severe abdomen pain
Nausea & vomiting
Raised serum amylase/lipase with persistent hypocalcaemia
Pathogenesis of acute pancreatitis (if caused by obstruction e.g. gallstones)
Damages duct lining.
Leakage and activation of pancreatic enzymes. e.g. Amylase released into blood.
Mild pancreatitis presents as
Swollen gland with fat necrosis
Severe acute pancreatitis presents as
swollen, necrotic gland with fat necrosis and haemorrhage (Grey Turner’s sign)
Haemorrhage into the subcutaneous tissues of flank.
(Cullen’s sign – periumbilicus).
Complications of pancreatitis
- Shock
- Intravascular coagulopathy
- Haemorrhage
- Pseudocysts (collections of pancreatic juice secondary to duct ruptutre)
Chronic pancreatitis - what is it and what can it lead to?
Progressive inflammatory disorder
parenchyma of pancreas is destroyed and replaced by fibrous tissue.
Irreversible destruction of the exocrine tissue, followed by destruction of the endocrine tissue
Leads to malnutrition and diabetes
The relationship between acute and chronic pancreatitis
Not two distinct diseases but a continuum:
Recurrent acute can develop chronic pancreatitis
Both genetic and environmental factors:
Experimental protocols can be modified to induce each condition
Clinical presentation of chronic pancreatitis
Intermittent abdo pain, back pain and weight loss
Fibrosis of exocrine tissue – can mimic carcinoma macroscopically and microscopically
Chronic Pancreatitis Aetiology
Toxic –alcohol, cigarette smoke, drugs, hypercalcaemia, hyperparatyroidism infections
Idiopathic
Genetic CFTR (cystic fibrosis gene), PRSS1, SPINK- 1 mutations
Autoimmune
Recurrent acute pancreatitis
Obstruction of main duct – cancer, scarring
Pathogenesis of chronic pancreatitis
Ductal obstruction by concretions (protein plugs)
Direct toxic effects – e.g. alcohol
What are the physiological effects of chronic pancreatitis?
Localised, irregular involvement of the gland early on, later global atrophy.
Dilated and distorted ducts
Calculi, esp in alcohol induced cases.
Fatty replacement. Fibrosis
Pseudocyst formation
What are the complications of chronic pancreatitis?
Malabsorption of fat (lack of lipases)
Steatorrhoea
Impairment of fat soluble vitamin absorption –A,D, E and K
Diarrhoea, weight loss and cachexia
Diabetes (late feature)
Pseudocysts
Stenosis of common bile duct/duodenum
Severe chronic pain