Cavernous liver hemangioma

A cavernous liver hemangioma or hepatic hemangioma is a benign tumor of the liver composed of large vascular spaces lined by monolayer hepatic endothelial cells. It is the most common benign liver tumour, and is usually asymptomatic and diagnosed incidentally on radiological imaging or during laparotomy for other intra-abdominal issues. Liver hemangiomas are thought to be congenital in origin with an incidence rate of 0.4 – 7.3% as reported in autopsy series.

Several subtypes exist, including the giant hepatic haemangioma (>10cm), which can cause significant complications.

Diagnosis
Liver hemangiomas are typically hyperechoic on ultrasound though may occasionally be hypoechoic; ultrasound is not diagnostic. Computed tomography (CT), magnetic resonance imaging (MRI) or single-photon emission computed tomography (SPECT) using autologous labelled Red Blood Cells (RBC) with Tc-99m is diagnostic. Biopsy is avoided due to the risk of haemorrhage.

Hepatic hemangiomas can occur as part of a clinical syndrome, for example Klippel–Trénaunay syndrome, Osler–Weber–Rendu syndrome and Von Hippel–Lindau syndrome.

Types

 * Typical hepatic hemangioma
 * Atypical hepatic hemangioma
 * Giant hepatic hemangioma
 * Flash filling hepatic hemangioma – can account for up to 16% of all hepatic hemangiomas
 * Calcified hepatic hemangioma
 * Hyalinized hepatic hemangioma
 * Other unusual imaging patterns
 * Hepatic hemangioma with capsular retraction
 * Hepatic hemangioma with surrounding regional nodular hyperplasia
 * Hepatic hemangioma with fatty infiltration
 * Pedunculated hepatic hemangioma
 * Cystic hepatic hemangioma – rare
 * Fluid-fluid level containing hepatic hemangioma – rare

Giant hepatic hemangioma
This large, atypical hemangioma of the liver may present with abdominal pain or fullness due to hemorrhage, thrombosis or mass effect. It may also lead to left ventricular volume overload and heart failure due to the increase in cardiac output which it causes. Further complications are Kasabach–Merritt syndrome, a form of consumptive coagulopathy due to thrombocytopaenia, and rupture.

Imaging follow-up
A United States practice is to perform liver ultrasound at 6 months and 12 months after the initial diagnosis, and if the size has not increased, further follow-up is not necessary. Particular situations that may indicate imaging are:
 * New onset abdominal pain
 * Initiation of estrogen therapy
 * Pregnancy
 * Hemangiomas larger than 10 cm, where it can be appropriate to perform an ultrasound follow-up annually.

Surgical treatment
For most patients, the natural history of cavernous hemangiomas in the liver remains uneventful, and surgical intervention can be avoided. The observation of asymptomatic lesions with routine follow-up with CT scan or ultrasonography is often sufficient. Indications for the surgical removal of hemangioma may include the development of pain, especially in patients with rupture, rapidly enlarging lesions, profound thrombocytopenia, or an uncertain diagnosis of a liver mass. Surgery for large masses is performed with enucleation or  resection.

The surgical procedure is the choice of the individual surgeon – the commonest being enucleation and resection. Massive blood loss can occur during surgery and may result in an operative mortality. Though liver resections can be safely accomplished in specialised units, occasional postoperative complications (bile leak) do occur. Enucleation may represent a safer surgical option with fewer complications for the treatment of haemangiomas, especially in centres with limited experience in liver resections. Most patients fully recover from the procedure and are only hospitalized for less than one week after the procedure.