Liver abscess & cysts

Question 1

Define

Answer 1

Abscess: liver infection resulting in a walled off collection of pus

Cyst: liver infection resulting in a walled off collection of cyst fluid

Question 2

Cause

Answer 2

Pyogenic (producing pus)

• Escherichia coli
• Klebsiella
• Enterococcus
• Bacteriodes
• Streptococci
• Staphylococci
• 60% are caused by biliary tract disease (e.g. gallstones, strictures, congenital cysts)
• 15% have unknown cause

Amoebic abscess

• Caused by Entamoeba histolytica

Hydatid cyst:

• Caused by tapeworm Echinococcus granulosis

Other causes: TB

NOTE: hydatid = a cyst containing watery fluid

Question 3

Epidemiology

Answer 3

Pyogenic is the most common type of liver abscess in the industrialised world

Amoebic liver abscess - most common WORLDWIDE

Hydatid cysts - common in sheep-rearing countries

Question 4

Symptoms

Answer 4

• Fever
• Malaise
• Nausea
• Anorexia
• Night sweats
• Weight loss
• RUQ/epigastric pain that may be referred to the shoulder (due to irritation of the diaphragm)
• Jaundice
• Diarrhoea
• Pyrexia of unknown origin

IMPORTANT: make sure you ask about foreign travel

Question 5

Signs

Answer 5

Fever - continuous or spiking

Jaundice

Tender hepatomegaly (right lobe affected more than left)

Right lung base:

• Dullness to percussion
• Reduced breath sounds
• Due to reactive pleural effusion

Question 6

Investigations

Answer 6

Bloods

• FBC
  
  • Mild anaemia
  • Leukocytosis
  • High eosinophils (if hydatid disease)
• LFTs
  
  • High ALP
  • High bilirubin
  • High ESR and CRP
• Blood cultures
• Amoebic and hydatid serology

Stool MC&S - for E. histolytica

Liver US or CT/MRI - localises structure of mass

CXR - check for right pleural effusion or atelectasis, raised hemidiaphragm

Aspiration and culture of the abscess material

• Most pyogenic liver abscesses are polymicrobial
• Amoebic abscesses have fluid of necrotic hepatocytes and trophozoites