Hepatic angiosarcoma

Hepatic angiosarcoma is a rare malignancy but is still the third most common primary liver tumour. They have a variable appearance on both CT and MRI, reflecting the pleomorphic histological nature. Prognosis is very poor, with survival uncommon beyond one year from diagnosis. 

Terminology

Hepatic angiosarcoma was previously known as Kupffer cell sarcoma. 

Epidemiology

Hepatic angiosarcomas account for ~1% of primary liver tumours. MostThey most commonly occursoccur in patients in their 60-70s60-70 years of age with a male predominance (M:F = 4:1) ^1-3. 

Clinical presentation

Patients typically have non-specific abdominal symptoms and may present with an abdominal mass or hepatomegaly. PatientsThey can also present with spontaneous rupture and haemoperitoneum ^1,5. 

Pathology

Hepatic angiosarcomas arise from malignant spindle cells of endothelial origin. Metastases are common at presentation, affecting lung and spleen.

Aetiology

Most hepatic angiosarcomas arise spontaneously, although haemochromatosis and neurofibromatosis type 1 have also been associated.

Environmental exposure to Thorotrast, arsenic, ionising radiation, and vinyl chloride have been implicated as risk factors, but such exposure is now rare.

HistologyMicroscopic appearance

Histology demonstrates varied appearances of solid nodules/masses or as sinusoidal or cavernous spaces. 

Radiographic features

Hepatic angiosarcomas most commonly present as multiple masses but can occur as a single heterogeneous mass ^2,4. 

CT

• hypoattenuating masses (some may be hyperattenuating reflecting haemorrhage) on both non-contrast and contrast-enhanced CT

• nodular enhancement is common

MRI

Findings reflect the haemorrhagic nature of angiosarcomas with fluid-fluid levels often a feature ²: 

• T1/T2: heterogeneous areas of high signal reflecting mixed tumour and haemorrhage

• T1 C+ (Gd): heterogeneous enhancement with progressive filling

Nuclear medicine

• The tumours are avid on FDG PET-CT ⁵

Treatment and prognosis

It typically rapidly progresses with metastases and high recurrence rate although partial liver resection may be successful if it is confined to one lobe of the liver. 

Prognosis is poor with hepatic angiosarcomas being resistant to chemotherapy and radiation therapy. Median survival is less than six6 months and survival beyond one1 year is rare.