Editing 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


[[Category:Liver]]