Liver haemangioma

Epidemiology

• Most common benign tumour of liver
• Women 4:1
• Typically 20-50yo

Aetiology

• Cause unclear
• ?congenital lesions complicated by vascular ectasia
• ?Acquired abnormality of normal hepatic vasculature with abnormal enlargement
• ?hormonal association

Pathophysiology

• Benign
• Typically solitary
• >5cm = 'giant'
• Microscopically: dilated, cavernous vascular channels of various sizes, lined by a single layer of flat endothelium and filled with blood. The vascular compartments are surrounded by thin connective tissue containing occasional calcifications and fibrosis.
• Enlargement is by ectasia rather than neoplasia
• Can involute or thrombose, creating a dense fibrotic mass that looks similar to malignancy

Presentation

• Asymptomatic (50-90%)
• Symptomatic
  • Typical liver mass symptoms - pain comes from haemangioma thrombosis or stretching of Glisson's capsule - nonspecific visceral abdo pain. Can have other nonspecific symptoms such as nausea and early satiety. Can lead to mass effect - obstructive jaundice, GOO etc.
  • Can cause AV shunting and CCF
  • Likelihood of symptoms is higher with increasing size
• Complications
  • Rupture/haemorrhage - 30% mortality rate, but exceedingly rare
  • Kasabach-Meritt syndrome - rare - haemangioma thrombocytopaenia syndrome - consumptive thrombocytopaenia as a large haemangioma traps platelets - can lead to DIC. Often triggered by simple dental or surgical procedure. Mortality 30%.
  • Malignant transformation has never been reported

Diagnosis (see also: Liver lesions under Radiology tab)

• Imaging
  • USS
    • Hyperechoic, with no hypoechoic rim
    • No flow on doppler
    • USS contrast agents can be used to clinch the diagnosis
  • CT (adequate for establishing diagnosis with typical noncon, arterial, PV and delayed phase findings)
    • Noncon: well-demarcated hypodense mass
    • Arterial: discontinuous, nodular peripheral enhancement (may not be seen on lesions <2cm)
    • PV: progressive peripheral enhancement with more centripetal fill-in (centripetal filling may be absent in larger lesions with fibrosis)
    • Delayed: further irregular fill-in, therefore iso or hyper attenuating to liver parenchyma
    • Rim enhancement is NEVER a haemangioma
    • Regressed or thrombosed lesions appear dense and fibrotic - can mimic malignancy
    • Similar CT appearance to neuroendocrine hepatic mets
  • Edge often lobulated
  • Progressive infilling
  • MRI is the best test - dedicated haemangioma protocol has 91% sens and 95% spec
    • Very high t2 signal - 'light bulb sign'
    • Follows blood pool in terms of contrast signal
• Percutaneous biopsy
  • Contraindicated
• Blood tests
  • Generally normal except Kasabach-Merritt syndrome

Natural history

• Most lesions remain stable
• 10-15% regress during follow-up
• Observation vs intervention results in a similar incidence of complications
• Rapid enlargement is unusual - need to think about alternative diagnosis
• Avoidance of pregnancy is NOT indicated for women - but be aware that it can cause them to increase in size

Management

• Observation
  • Indicated in asymptomatic patients, even pregnant women and those on COCP
• Embolisation
  • Indicated in acute haemorrhage/rupture or Kasabach-Merritt syndrome
• Surgery
  • Indications
    • Symptoms - extreme pain or mass-related effects - needs to be weighed against morbidity of procedure
    • Complications - intraperitoneal haemorrhage resistant to embolisation
    • Kasabach-Merritt syndrome - should be done urgently despite coagulopathy. Again, try embolisation first.
    • Diagnostic uncertainty/inability to rule out malignancy - significant change in size
  • Procedure
    • Enucleation with arterial inflow control
      • Decreased blood loss, operative time, complications, increased preservation of hepatic parenchyma compared to resection
      • Control hepatic artery inflow (Pringle - stop for 5 mins every 30 mins)
      • Incise Glisson's capsule to identify plane of pseudocapsule
      • Dissect along this plane
    • Anatomic/nonanatomic liver resection - used in cases of diagnostic uncertainty
• Non-operative
  • Transarterial embolization
    • Bridge to surgery in bleeding lesions
  • Percutaneous RFA
  • Percutaneous ethanol ablation
  • Hepatic radiation therapy

Follow-up

• MRI in 3-6 months initially to ensure no progression, then annually, and reduce from there for unchanging lesions

Paediatrics

• Typically part of a systemic process and multifocal when present
• Can result in CCF
• If symptomatic, 70% mortality rate
• Embolization first-line, along with cytotoxic drugs
• Will also need medical therapy for CCF
• Can give systemic corticosteroids, IV vincristine or interferon-alpha
• Surgical resection can be considered with severely symptomatic or ruptured tumours