Liver Flashcards
what does jaundice refer to and what is the compound responsible
jaundice is the yellowish discolouration of the sclera and skin
due to hyperbilirubinaemia
what is bilirubin
bilirubin is the normal breakdown product of haem - so it is usually formed from the destruction of red blood cells
under normal circumstances, what is the normal pathway of bilirubin
normally it is conjugated within the liver to make it water soluble
it is then excreted via bile into the GI tract
the majority of which is removed from the body in faeces as stercobilin or through urine as urobilinogen
what are the 3 main types/groups of jaundice
pre-hepatic
hepatic
post-hepatic
what is pre-hepatic jaundice and how will it appear in the blood
occurs when there is excessive red blood cell breakdown which overwhelms the livers ability to conjugate bilirubin
results in a build up of unconjugated bilirubin in the bloodstream
what is intrahepatic jaundice and how will it appear in the blood
occurs when there is dysfunction of the hepatic cells - resulting in that part of the liver losing the ability to conjugate bilirubin
occurs when some hepatic cells are dysfunctional and some still work perfectly, therefore it shows as a mixed picture in the blood with both conjugated and unconjugated hyperbilirubinaemia
what is post hepatic jaundice and how will it appear in the blood
occurs when there is an obstruction of biliary drainage
bilirubin has been conjugated alright and therefore shows as a conjugated hyperbilirubinaemia
what are some pre-hepatic causes of jaundice
haemolytic anaemia
drugs and toxins
haemoglobinopathies e.g. sickle cell
malaria
what are some intra-hepatic causes of jaundice
alcoholic liver disease
viral hepatitis
iatrogenic; medication
hepatocellular carcinoma
drugs and toxins
primary sclerosing cholangitis
what are some post-hepatic causes of jaundice
intra-luminal causes; gallstones
cholangiocarcinoma
strictures
pancreatic cancer and abdominal masses
how will the stools differ in each type of jaundice and why
pre-hepatic jaundice = unconjugated bilirubin, not water soluble so unable to removed in urine. so stercobilin builds up in faeces and that is what gives it the brown colour - so in pre-hepatic jaundice you will see dark brown faeces due to increased stercobilin
intra-hepatic jaundice = mixed conjugated and unconjugated, therefore see normal/decreased brown colour of faeces
post-hepatic jaundice = conjugated bilirubin and blockage of bile duct, no bile into GI tract, therefore no stercobilin in faeces, loses all brown colour and appears clay coloured
how will the urine colour differ in each type of jaundice
pre-hepatic = unconjugated bilirubin, not water soluble and therefor no urobilinogen in urine, normal colour/acholuric
hepatic = mixed conjugated/unconjugated, urine appears normal/slightly darker
post-hepatic = conjugated bilirubin, blockage of bile tract, no bilirubin into GI tract, all removed through urine as urobilinogen, results in dark brown coloured urine
what specialist blood tests can you do to elicit information regarding the location or severity of the jaundice
bilirubin - quantify degree of suspected jaundice
albumin - check the livers synthesising function
AST and ALT - markers of hepatocellular injury
Alkaline Phosphatase - raised in biliary obstruction (can be raised in other things)
Gamma-GT - more specific for biliary obstruction than alkaline phosphatase
what imaging can be used in cases of jaundice
first line is usually a USS abdomen
magnetic resonance cholangiopancreatography (MRCP) can be used to visualise the biliary tree - typically performed if the jaundice is obstructive
liver biopsy
pathophysiology of simple liver cysts
thought to be due to congenitally malformed bile ducts that dont connect to the extrahepatic ducts
leads to a local dilatation filled with bile-like fluid
clinical features of simple liver cysts
normally asymptomatic and often detected incidentally on imaging
abdo pain, nausea and early satiety (due to compression of surrounding structures)
investigations and management of simple liver cysts
LFTs normal
USS remains imaging of choice
most cysts require no intervention
large ones may need follow up USS to check for growth
what is polycystic liver disease and what is it caused by
characterised by the presence of >20 cysts within the liver parenchyma
caused by either; autosomal dominant polycystic kidney disease (ADPKD) or autosomal dominant polycystic liver disease (ADPLD)
clinical features of polycystic liver disease
usually asymptomatic
in those with symptoms, abdo pain and hepatomegaly as cysts grow in size
what are the surgical interventions for liver cysts
US-guided aspiration - not routinely formed due to fluid re-accumulation
Laparoscopic de-roofing of cysts - for those experiencing symptoms
what are cystic neoplasms and what is the most common type
premalignant lesions
most common type is cystadenomas
what are the radiological features of a liver cyst that could indicate malignancy
septations
wall enhancement
nodularity
what is the management of cystic neoplasms of the liver
liver lobe resection (pre malignant lesions)
what causes Hydatid cysts
infection by tapeworm (Echinococcus granulosus)
clinical features of hydatid cyst
usually asymptomatic
main symptom is vague abdo pain caused by the mass effect on surrounding structures
investigations into all liver cysts
FBC and USS
why should aspiration or biopsy be avoided in both cystic neoplasms and hydatid cysts
cystic neoplasms = avoid peritoneal seeding of malignancy
hydatid cyst = avoid rupture
what are the four anatomical lobes of the liver called
right
left
caudate
quadrate
how do liver abscesses occur
as a result of bacterial infection spreading from the biliary or GI tract e.g. cholecystitis, cholangitis
what are the most common causative organisms in liver abscesses
E. coli
K. pneumoniae
S. constellatus
clinical features of liver abscess
present with fever, rigors and abdo pain
on examination patients have RUQ tenderness and hepatomegaly
what blood test along with clinical findings would indicate hydatid cysts more than any other pathology
eosinophilia
investigations into liver abscess
LFTs - raised ALP
USS abdo
CT imaging with contrast
management of liver abscesses
abx therapy
drained via image-guided aspiration of the abscess (either CT or USS)
surgery only indicated if the abscess has ruptured
what is an amoebic abscess and what causes it
most common extra-intestinal manifestation of amebiasis infection, caused by the organism entamoeba histolytica
what is the most common primary liver tumour
hepatocellular carcinoma (HCC)
what is the pathophysiology of hepatocellular carcinoma and what is it most commonly due to
result of a chronic inflammatory process affecting the liver
most common cause worldwide is viral hepatitis, other causes include chronic alcoholism
risk factors for hepatocellular carcinoma
viral hepatitis (hep B and C the most common)
high alcohol intake
advanced age
family history of liver disease
smoking
clinical features of hepatocellular carcinoma
vague, non-specific symptoms; fatigue, fever, weight loss, lethargy
dull ache in RUQ is characteristic of HCC
advanced disease may present with ascites or jaundice
lab tests for liver cancer
FBC
LFT
Platelets and clotting time
AFP - raised in 70% of cases
imaging of liver cancer
USS is method of choice followed by staging CT
if diagnosis is in doubt an MRI with biopsy can be done
management of liver cancer
surgery or transplantation are the only curative options
what are the most common cancers that metastasise to the liver
bowel, breast, pancreas, stomach and lung
what biomarker is most important in suspected hepatocellular carcinoma
AFP
