Hepatic angiosarcoma is the most common primary sarcoma of the liver and originates from vascular endothelial cells. It is an extremely aggressive malignancy — usually widespread at diagnosis. Known risk factors: thorotrast (contrast agent, no longer used), vinyl chloride (PVC production), arsenic, and anabolic steroids. Most cases (75%) are idiopathic. Median survival is 6 months. Risk of spontaneous rupture and hemoperitoneum is high (15-27%). At diagnosis, 80% are inoperable.
Age Range
50-80
Peak Age
65
Gender
Male predominant
Prevalence
Rare
Angiosarcoma is a malignant vascular tumor originating from hepatic sinusoidal endothelial cells or Kupffer cells. In thorotrast exposure, radioactive thorium dioxide particles accumulate in the reticuloendothelial system (spleen, liver, lymph nodes) causing chronic alpha radiation damage — latent period is 20-35 years. Vinyl chloride monomer is metabolized in the liver producing DNA-binding reactive metabolites (chloroethylene oxide) — causing mutagenic effects on sinusoidal endothelial cells. The tumor forms abnormal vascular channels creating cavernous blood-filled spaces — this architecture determines the enhancement pattern and hemorrhagic tendency. CD31, CD34, and ERG vascular endothelial markers are positive.
The presence of T1 hyperintense areas (hemorrhage of different stages) in multiple heterogeneous hepatic masses and hemangioma-like but irregular progressive centripetal filling on dynamic contrast imaging is the signature finding of hepatic angiosarcoma. Combined with thorotrast/vinyl chloride exposure history, the diagnosis is nearly definitive.
Multiple hypodense lesions or dominant large mass with accompanying smaller lesions. Hemorrhagic areas (50-70 HU) may be seen as hyperdense foci internally. In thorotrast exposure, diffuse dense calcification (thorotrast deposition) in liver and spleen.
Report Sentence
Multiple hypodense lesions are seen in the liver with internal hyperdense areas consistent with hemorrhage.
Heterogeneous peripheral enhancement — reflecting irregular vascular architecture. Unlike hemangioma's globular peripheral enhancement, it is irregular and asymmetric. In some cases, early intense homogeneous enhancement may also be observed.
Report Sentence
Heterogeneous peripheral enhancement is seen in arterial phase in the lesions, and malignant vascular lesion (angiosarcoma) should be primarily considered.
Progressive centripetal filling on delayed phase — hemangioma-like but faster and irregular. The entire lesion may not fill homogeneously — necrotic/thrombotic areas remain persistently hypodense.
Report Sentence
Progressive but incomplete centripetal filling is seen in delayed phase with non-enhancing necrotic areas favoring malignancy.
Hyperintense areas on T1 — intratumoral hemorrhage (methemoglobin). Hemorrhage is the most characteristic MRI finding of angiosarcoma. Different stages of hemorrhage (different T1 signal intensities) may be seen in multiple lesions.
Report Sentence
Hyperintense areas consistent with hemorrhage of different ages are observed in the lesions on T1.
Markedly heterogeneous hyperintensity on T2. Vascular channels and cystic/necrotic areas bright, solid components intermediate signal, hemosiderin deposits hypointense. Fluid-fluid levels may be seen (sedimentation of blood products of different density).
Report Sentence
The lesions show markedly heterogeneous signal on T2, reflecting coexistence of vascular, necrotic, and hemorrhagic components.
Spontaneous rupture with hemoperitoneum — emergency complication of angiosarcoma. Perihepatic and perisplenic free fluid, hyperdense (40-70 HU) hemoperitoneum, active bleeding focus (contrast extravasation).
Report Sentence
Hyperdense free fluid in the perihepatic/perisplenic area is consistent with hemoperitoneum — hepatic angiosarcoma rupture should be primarily considered.
Criteria
Multiple lesions distributed in both lobes — most commonly encountered form (60-80%).
Distinct Features
Multiple hypodense lesions most confused with metastasis. However, intratumoral hemorrhage and hemangioma-like enhancement are specific to angiosarcoma. Resection is generally not possible.
Criteria
Single large dominant mass — less common (20-30%). May be accompanied by smaller satellite lesions.
Distinct Features
Large heterogeneous mass may be confused with HCC or cholangiocarcinoma. Hemorrhagic component and vascular enhancement pattern are distinguishing. Resection may be considered but does not change prognosis.
Criteria
Thorotrast (thorium dioxide) exposure history — develops after 20-35 year latent period.
Distinct Features
Diffuse dense calcification caused by thorotrast deposition in liver and spleen is pathognomonic. Diagnosis of angiosarcoma developing on this background is relatively easy. Splenic angiosarcoma may also develop concurrently.
Distinguishing Feature
Hemangioma shows homogeneous light-bulb bright signal on T2 (isointense with fluid), does not contain T1 hyperintense hemorrhagic areas. Centripetal enhancement of hemangioma is regular and symmetric — angiosarcoma's is irregular and asymmetric. Rupture risk is absent in hemangioma (except giant hemangioma).
Distinguishing Feature
EHE shows multiple peripherally distributed lesions (with capsular retraction), has slower course and better prognosis than angiosarcoma. EHE lesions show target sign (peripheral halo + central hypodensity). Intratumoral hemorrhage and rupture are much more common in angiosarcoma.
Distinguishing Feature
HCC usually develops in cirrhotic liver, AFP is elevated. Angiosarcoma develops in non-cirrhotic liver, AFP is normal. Washout is typical in HCC (LI-RADS), progressive centripetal filling is seen in angiosarcoma. Intratumoral hemorrhage may occur in HCC but multiple hemorrhages in multiple lesions are more specific to angiosarcoma.
Urgency
emergentManagement
surgicalBiopsy
NeededFollow-up
3-monthHepatic angiosarcoma is a malignancy with extremely poor prognosis — median survival is 6 months. Spontaneous rupture and hemoperitoneum is a complication requiring emergency surgery (15-27%). Since 80% are inoperable at diagnosis, curative treatment is generally not possible. Biopsy carries bleeding risk due to vascular nature but is required for definitive diagnosis. Chemotherapy (doxorubicin) may provide palliative response. Radiation therapy is ineffective. Transplantation is contraindicated (high recurrence). Risk factor exposure (vinyl chloride, arsenic) should be investigated and reported. 3-month CT/MRI follow-up is recommended.
Highly aggressive tumor, usually unresectable at diagnosis. Median survival is 6 months. Surgical resection may be possible in limited cases. Response to chemotherapy is poor. Risk of spontaneous rupture and hemoperitoneum exists.