Infective liver lesions

• Infective liver lesions


  • Investigations
  • Options for treatment
• Classification of cystic liver lesions

  • Infective
  • Hydatid
  • Amoebic
  • Pyogenic
  • Others...
  • Non-infective
  • Simple cysts
  • Haemangioms
• Pyogenic Liver Abscess


  Most common liver abscess
• Pyogenic Liver Abscess


  • Single or multiple (50/50)
  • Pt at risk: Male, >50yrs, transplant, DM, HIV, underlying malignancy, liver surgery i.e resection
  • Affect R lobe > L lobe (size)
  • Usually confined to a lobe
• Pyogenic abscess causes


  • Portal spread: Appendicitis, diverticulitis, IBD, perforated hollow viscus
  • Billiary-Spread: Ascending cholangitis, instrumentation i.e bile duct stent, billiary-enteric anastomosis
  • Local extension: Peri-nephric abscess, diverticulitis, cholecystitis, sub-phrenic abscess
  • Arterial spread: Endocarditis, indwelling lines, dental work, pneumonia, septic arthritis, TB
  • Trauma / surgery: Infected haematoma, arterial embolisation or ligation, ablation therapies
  • Cryptogenic: 20-40% of cases the cause may have resolved by presentation
• Microbiology of pyogenic liver abscess

  • 40% mono-microbial: likely arterial spread
  • 40% poly-microbial: likely portal spread
  • 20% culture negative
  • Predominantly gram -ve
  • E.coli (66%), Enterococcus, Klebsiela, Strep. faecalis, proteus vulgaris
  • Gram +ve
  • Staph and strep associated with endocarditis and catheters
  • Anaerobes - Bacteroides fragiles
  • Atypical - Mycobacterium and fungi associated with immunocompromised or chemo
• Presentation of pyogenic liver abscess


  • RUQ pain, fever, tachycardia, jaundice (10-30%)
  • Diaphragm irritation with cough, dyspnoea
  • If ruptured: peritonitis, pleural/pericardial effusion
• Investigations for pyogenic liver abscess

  • Bloods: Raised WCC, CRP, ESR, ALP +/- Bili
  • Blood cultures reveal organism in 50% of cases
  • AXR/CXR: Elevated diaphragm on side of abscess, pleural effusion (reactive or ruptured), air-fluid level, portovenous gas
  • U/S: Round / oval hypo-echoic lesion, septa or debris, well defined borders, internal echoes
  • CT: Well defined, round, hypo-dense lesion, rim enhancement in arterial phase, may have air-fluid level
• Management of pyogenic liver abscess

  1. Treat cause / source

  2. Abscess managed by Percutaneous drainage and culture

  3. Contraindicated if coagulopathic, close to mayor vessel, ascites

  4. IV Ab's - Gram -ve and anaerobic cover

  5. Open or laparoscopic drainage reserved for Failed less invasive treatment

  6. Surgery anyway required for underlying cause/source i.e appendicitis
• Amoebic abscess


  Worldwide endemic parasitic infection by entamoeba-histolytica
• Amoebic abscess


  • Non-flagellated pseudopod forming protozoa
  • Infects 10% of world population - most common abscess worldwide
  • More common in sub-tropical areas and poor sanitation
  • Superior anterior right lobe most of the time
  • Solitary or multiple
  • Necrotic centre => anchovy paste like pus, odourless
• Entamoeba histolytica


  • Exists as cyst in vegetative form
  • Passes through gut unharmed and becomes trophozoite in colon
  • Invades mucosa causing flask shaped ulcers
  • Enters portal circulation towards the liver
  • It then may: multiply in liver -> block intra-hepatic portal radicles -> hepatocyte infarction -> secretes proteolytic enzyme -> lysis of hepatic parenchyma = liquefactive necrosis
  • pass liver sinusoid to form lung or brain abscess
• Presentation of amoebic abscess

  • As for pyogenic but added travel Hx, hepatomegaly
  • May be acute (more severe) or chronic
  • Chronic usually solitary, acute usually multiple
• Investigations for amoebic abscess

  • Bloods: Raised WCC, ALP, transaminases, PT +/- bili
  • Serology: Fluorescent antibody test positive
  • AXR/CXR: Elevated right diaphragm, effusion if ruptured
  • U/S: Sensitive but not specific, no wall echoes
  • CT: Sensitive, not specific, well rounded, thick rim enhancement, ragged peripheral edge(oedema), central septa +/- fluid levels
  • Nuclear medicine: Does not enhance with Gallium or Technitium-99 scan (contains no WBC)
• Management of amoebic abscess

  1. Medical treatment

  2. Metronidazole 750mg tds po x 10/7

  3. Fever settles in 3-5days, abscess resolution may take up to a year

  4. Surgical drainage indicated if Medical treatment fails

  5. Secondary bacterial infection

  6. Left lobe of liver - risk of rupture into pericardium

  7. Large > 5cm (relative indication)
• Echinococcal cyst


  • Echinococcus granulassi infection at cyst or larval stage
  • Round, fluid filled cysts with calcifications and has 3 layers
  • Outer layer: 2-4mm thick compressed liver tissue and fibrous capsule
  • Middle layer: 2mm thick anuclear hyaline ectocyst
  • Inner layer: Internal germinal endocyst derived from parasite
  • Daughter cysts
  • True replications of mother cyst
  • Smaller than mother cyst
  • Most common in sheep raising areas where dogs have access to infected offal
• Echinococcus granulassi


  • Life cycle: Tapeworm live in dog that ate intestine of sheep infected with cysts -> scolices in cysts attach to intestinal wall -> become taenia -> sheds ova in faeces -> fecal-oral spread to sheep, cattle, pigs and humans -> ovum capsule dissolved in stomach -> ovum now burrows into SB mucosa -> portal system -> liver
  • Once in liver it may 70% liver cyst
  • pass liver sinusoid to infect lungs, brain, spleen, bone
• Presentation of echinococcal cyst

  • Mostly asymptomatic and found incidentally
  • Sepsis if secondary infection
  • Other organs affected i.e brain
  • Dull RUQ pain
  • Anaphylaxis if it ruptures
  • DO NOT DRAIN!!!
• Investigations for echinococcal cyst

  • Serology: ELISA for echinococcal antibodies
  • 85% sensitivity
  • U/S: Sensitive, well defined cyst, budding sign on membrane, free floating hyper-echoic sand (scolices), wall calcifications
  • CT: Sensitive, well defined hypodense cyst, ring-like calcification of pericyst, daughter cysts within mother cyst peripherally, rosette-appearance
  • If entire cyst calcified = dead or inactive
• Management of echinococcal cyst

  1. Surgical excision

  2. NB: Do not rupture cysts

  3. Anaphylactic shock, peritoneal contamination and recurrence

  4. Complete excision cyst and scolicidal agent instillation

  5. May be done by sectionectomy

  6. PAIR procedure

  7. Small uncomplicated cysts or unfit patient

  8. Albendazole
• The 3 main types of infective liver lesion are managed differently
• NB: Diagnose correct etiology
• Done by history, examination, blood tests and imaging
• Always exclude echinococcus before any aspiration or drainage is attempted