Pancreatic and Biliary Disease Flashcards
what is acute pancreatitis?
reversible inflammatory process ranging in severity from oedema and fat necrosis to parenchymal necrosis and severe haemorrhage
risk factors for acute pancreatitis
- gallstones
- alcoholism
how do gallstones lead to pancreatitis?
this obstructs the pancreatic duct which leads to irritation due to activation of pancreatic enzymes whilst in the organ, to cause inflammation of the pancreas
causes of acute pancreatitis
- obstruction of the duct system
- drugs: thiazides, azothiaprine, oestrogens, sulphonamides, methyldopa
- infections: mumps, mycoplasma
- metabolic: hypercalcaemic states
- acute ischaemia: thrombosis, embolism
- trauma
- genetic: cationic trypsinogen and trypsin inhibitor mutations
- idiopathic
pathogenesis of pancreatitis
pancreas is digested by its own enzymes being activated within the organ (autodigestion)
what activates the pancreatic enzymes?
- duct obstruction
- acinar cell injury
- defective intracellular transport
what happens when the duct gets obstructed?
- interstitial oedema
- impaired blood flow
- ischaemia
- acinar cell injury
- leads to activation of enzymes
- alcohol/trauma/drugs/viruses: release of intracellular proenzymes and hydrolases which activates enzymes
what happens if there is defective intracellular transport?
- delivery of proenzymes to lysosomal compartment, leading to activation of enzymes and acinar cell injury
what happens when there is acinar cell injury?
- interstitial inflammation and oedema
- proteolysis
- fat necrosis
- haemorrhage
what causes fat necrosis?
lipases and phospholipases
what does elastase do?
digests the walls of the blood vessels, leading to haemorrhage
clinical features of acute pancreatitis
- abdominal pain
- acute abdomen
- elevated amylase, lipases
- fat necrosis, hypocalcaemia
why is there hypocalcaemia in pancreatitis?
due to extensive fat necrosis, a lot of calcium is pulled out from the bloodstream, causing calcium deposits and hypocalcaemia
complications of pancreatitis
- pancreatic abscess
- pseudocyst
- ARDS; renal failure
- infection by gram negative organisms
- shock
- septicaemia
what type of damage is there in chronic pancreatitis?
irreversible
pathological features of chronic pancreatits
- fibrosis
- present with diabetes mellitus
- recurrent pancreatitis attacks which slowly destroy the pancreas
causes of chronic pancreatitis
- alcohol abuse
- long standing duct obstruction
- hereditary pancreatitis
- tropical pancreatitis
- idiopathic
- autoimmune pancreatitis
pathogenesis of chronic pancreatitis
- necrosis/fibrosis due to acute inflammation, leading to fibrosis, duct distortion and altered secretions, leading to loss of parenchyma and fibrosis
pathogenesis of hereditary pancreatitis
- mutations in the PRSS1 gene
- this codes for autolysis-resistant trypsin, leading to pancreatitis
complications of chronic pancreatitis
- pseudocyst
- malabsorption
- diabetes
- carcinoma
clinical features of autoimmune pancreatitis
- weight loss, abdominal pain, jaundice
- imaging: diffuse enlargement of pancreas, narrowing of the duct
- IgG4 plasma cells present
- elevated serum IgG4
if the patient presents with jaundice, which part of the pancreas is most likely affected?
head of the pancreas due to obstruction of a section or tributary of the CBD
treatment of autoimmune pancreatitis
steroids
IgG4 related immune disorders
- biliary tree disorders like PSC
- idiopathic retroperitoneal fibrosis
- riedel thyroiditis
- chronic sclerosing sialadenitis
what can of tumours can occur in the pancreas?
- cystic neoplasms
- intraductal neoplasms
- carcinoma
- islet cell tumours
- pancreatoblastoma
what kind of tumours are pancreatic cystic tumours?
intraductal papillary mucinous tumours
what is the common carcinoma in the pancreas?
adenocarcinoma
aetiology of pancreatic carcinoma
- elderly
- smoking
- chronic pancreatitis and diabetes
- familial clustering (HNPCC, breast/ovary, FAMMM, hereditary pancreatitis)
risk factors for gallstones
- age
- women (female, fertile, fat, forty, fair)
- oestrogens
- hereditary factors
pathogenesis of cholesterol gallstones
- cholesterol: bile gets supersaturated with cholesterol, gallbladder hypomotility promotes nucleation which accelerates cholesterol nucleation, mucus hypersecretion traps crystals, permitting aggregation into stones
pathogenesis of pigment gallstones
- infections (unconjugated bilirubin increases in infection)
- haemolysis
what disease is almost always associated with gallstones?
cholecystitis
what is cholecystitis?
acute inflammation precipitated by obstruction of neck or cystic duct
causes of acalculus cholecystitis
- post-op state
- severe trauma
- burns
- multisystem failure/sepsis
- portpartum
complications of cholecystitis
- empyema
- gangrenous cholecystitis
- ascending cholangitis
what happens to the gallbladder in times of obstruction?
- thickened walls
- becomes trabeculated
where does a carcinoma of the gallbladder affect more commonly?
- fundus
- neck
what is the prognosis of pancreas and gallbladder cancers
poor
types of liver benign tumours
- liver cell adenoma
- cavernous haemangioma
risks factors for hepatocellular carcinoma
- HBV
- HCV
- alcoholic disease
- haematochromatosis
types of morphology of HCC
- unifocal
- multifocal
- diffusely infiltrative
what is fibrolamellar carcinoma associated with?
younger population
risks of cholangiocarcinoma
- PSC
- caroli
- parasites
where does cholangiocarcinoma affect?
bile ducts in the liver
where is the most common site for metastasis?
liver
how would LFTs be with tumour infiltrating the liver?
they can still remain normal because there is enough normal viable tissue to compensate for the lost
