47-year-old woman, otherwise healthy, presents to the primary physician with recent onset of intense abdominal pain in the right upper quadrant. Physical examination was unremarkable; lab work revealed mild anaemia (Hb 10 g/dL). Abdominal ultrasound showed a large lesion of the right liver lobe and magnetic resonance imaging (MRI) was performed.
Abdominal MRI showed a dominant mass occupying most of the right liver lobe, measuring 11 cm (Fig. 1), heterogeneous but mostly hyperintense on T2WI and hypointense on T1WI, with areas of higher intensity on T2WI and scattered hypointense spots that were suggestive of intra-tumoral haemorrhage and hemosiderin deposits, respectively. The lesion showed marked restricted diffusion on high b values and, after contrast administration, there were multiple hypervascular foci suggestive of intra-tumoral haemorrhage and progressive extensive globular filling of the mass. The remaining lesions were much smaller in size and showed similar characteristics. Alpha-fetoprotein levels were normal.
Biopsy of the main lesion was performed under ultrasound guidance, and the patient was discharged. Pathology was suggestive of liver angiosarcoma, recommending excision of a single nodule if the results were not concordant with clinical and imaging findings.
Two weeks later, patient presents to the emergency department with severe anaemia (6,3 g/dL). Emergency CT was performed and showed spontaneously hyperdense areas within the dominant mass, with progressive filling after intravascular contrast injection, compatible with active bleeding (Fig. 2). A second percutaneous biopsy was performed simultaneously with embolisation of the main lesion (Fig. 3a-c), to confirm the diagnosis and treat the bleeding. Pathology from both liver specimens obtained reported a liver angiosarcoma with sinusoidal growth and focal atypia.
Follow-up CT performed 1 month later showed massive tumour necrosis and no internal enhancement (Fig. 3d-e). Treatment included a paclitaxel regimen followed by doxorubicin, with poor tumoural response 6 months later.
Liver angiosarcoma is a rare malignant tumour and represents less than 2% of primary liver tumours . It is associated with thorium dioxide, arsenic powder and vinyl chloride, and is more frequent in the 6th and 7th decades in males . Most cases, however, do not show any association with known aetiologic factors . Angiosarcoma is characterised by rapid growth, and most patients suffer from chronic liver disease. Symptoms are variable and nonspecific and include weakness, weight loss and abdominal pain . Alpha-fetoprotein and CA 19-9 levels are usually normal.
Diagnosis is challenging, even when a histological specimen is obtained due to variability of tumour composition within an individual lesion . There is a high risk of bleeding from biopsy, and open liver biopsies or laparoscopy may be more accurate and safer. For patient safety and due to the high vascular nature of the lesion, the second biopsy was done in the interventional radiology suite simultaneously with embolisation of the bleeding tumour to confirm the histology diagnosis.
Main differential diagnoses include cavernous haemangioma, hepatocellular carcinoma, epithelioid haemangioendothelioma, hypervascular metastases, Kaposi sarcoma and hepatic peliosis . Lesions have increased vascularity, which translates into increased i.v. contrast uptake in CT and MRI scans and they may show progressive and globular enhancement, much like a cavernous haemangioma. However, solitary liver angiosarcomas are uncommon due to their insidious course, and multiple haemangiomas are atypical . In comparison with haemangiomas, enhancement is usually less than that of the aorta and generally does not follow a centripetal pattern. On T1-weighted sequences, there is decreased signal with focal areas of high signal intensity, suggesting intra-tumoral haemorrhage . There is increased signal on T2-weighted sequences. Elevation of the apparent diffusion coefficient level has been described [8, 9].
The majority of patients have unresectable lesions at diagnosis, as was the case with our patient. Metastasis is also common at presentation, in the lungs, spleen or bone . Not surprisingly, prognosis is poor, with a mean patient survival of 6 months without treatment, and even when treated only 3% of patients survive over 2 years.
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