Liver cysts

Question 1

What is a liver cyst?

Answer 1

Liver cyst = walled off collection of fluid/pus within the liver tissue

Question 2

What is the aetiology of liver cyst?

Answer 2

Simple cysts - Believed to be congenital in origin

PCLD - Congenital (Associated with AD PCKD)

Hydatid cysts - Caused by infestation of parasite Echinococcus granulosus (tapeworm)

Found worldwide, particularly in areas of sheep and cattle farming

Question 3

What are the risk factors of liver cyst?

Answer 3

PCLD:
Female
Increased oestrogen level
PCKD
FH

Hydatid cysts:
Living in sheep-rearing countries

Question 4

What is the epidemiology of liver cyst?

Answer 4

Unknown, as most are asymptomatic (90%) - Estimated 5%

Usually found as an incidental finding

Question 5

What are the symptoms of liver cyst?

Answer 5

Usually no constitutional symptoms or abdominal pain
IF large – e.g. PCLD
Dull RHS UQ pain
Abdominal bloating 
Early satiety

IF cyst torsion
Acute abdomen

IF cyst rupture
Into biliary tree: Jaundice, cholangitis
Into peritoneal cavity: Anaphylactic shock

Question 6

What are the signs of liver cyst?

Answer 6

Simple cysts
IF large: palpable abdominal mass

PCLD
Hepatomegaly
Portal hypertension
Palpable RUQ mass

Question 7

What investigations are appropriate for liver cyst?

Answer 7

Bloods
LFTs (PCLD only)
ALT/AST: Mildly elevated
AlkPhos: Mildly elevated

FBC: Leukocytosis (abscess), eosinophilia (40% of hydatid cysts)
CRP/ESR: Normal except in hydatid cysts

Stool MC+S - Tapeworm eggs

US - Simple cysts: Unilocular, thin walled, fluid-filled (low density) lesion

Abdo CT - Simple cysts/PCLD = Well circumscribed lesions that do not enhance with contrast (Attenuation is consistent with water)
Hydatid cysts - Daughter cysts within thick-walled main cavity

IF jaundiced with hydatid disease
ERCP - Determine if rupture into bile duct