Thorotrast induced haemangiosarcoma of the liver - 'The answer is on the film'

Clinical History

A 68 year old man presents with anorexia and weight loss. Following liver biopsy he becomes hypotensive and develops abdominal pain and an angiogram is performed.

Imaging Findings

A 68-year-old man presented to the local hospital with weight loss and anorexia. On examination the patient was cachectic, the liver was enlarged, but there was no ascites, splenomegaly or lymphadenopathy. An abdominal ultrasound (Fig. 1) showed a 6 cm hyperechoic tumour of the right lobe of the liver as the only abnormality. The spleen was not clearly identified. CT (Fig. 2) confirmed a large liver tumour, which in the absence of any other sites of disease was deemed to be a primary hepatic neoplasm. Ultrasound guided biopsy was performed without difficulties. However following the biopsy the patient had evidence of internal haemorrhage with hypotension, tachycardia and peritonism. An emergency laparotomy failed to reveal the site of bleeding and the patient was transferred to the regional centre for angiography and possible embolisation. Extensive malignant neovascularisation was demonstrated in the liver (Fig. 3a), but no active bleeding was seen. It was noted however that the spleen was abnormal, being small and of very high attenuation (Fig. 3b). An old abdominal film (Fig. 4a & b) was found, which demonstrated the classical features of previous thorotrast deposited within the spleen and abdominal lymph nodes. The patient remained stable, but died a month later from the underlying tumour. With the benefit of hindsight, this is one of the very few cases, where a histological diagnosis could have been made from the imaging findings alone.

Discussion

Thorotrast is a suspension of thorium dioxide previously used as a radiographic contrast medium. Patients injected with thorotrast, from the 1920's to early 1950's received chronic internal exposures to Thorium 232, an alpha emitter. It was last used in 1955 [1]. Epidemiological studies have observed markedly elevated risks of death from hepatic and haematological cancers and extensive chromosomal damage among the patients [2]. In a Japanese study 412 patients with previous thorotrast administration were followed up. The rate ratio for all deaths compared to controls increased after a latent period of 20 years following injection of thorotrast. Significantly increased rate ratios were seen for a number of conditions including liver cancer (x 35.9), cirrhosis (x 6.9), leukaemia (x 12.5) and lung cancer(x 2) [3]. The use of thorotrast as a contrast medium is now only of historical interest. Thorotrast induced angiosarcoma, though rare, still generates considerable clinical interest because of the characteristic opacification of the liver, spleen and lymph nodes, and the long latency period between exposure and the onset of tumour. Although the development of haemangiosarcoma occurs up to 43 years after exposure [1], most of the patients have a latent period of 15-20 years [1,4]. Hepatic angiosarcoma is a rare tumour with a fatal course. It represents 1-2% of all primary hepatic tumours and it is the most frequent primary mesenchymal tumour of the liver. Its incidence is increased with exposure to thorotrast, vinyl chloride, arsenic and anabolic steroids. Peak incidence occurs in 60-70 year old age group with a 4 to 1 male preponderance [4]. The tumour may be encountered in patients with haemochromotosis and von Recklinghausen disease (neurofibromatosis type 1). Although the appearances on diagnostic imaging may be non specific, the hypervascularity of the tumour in combination with risk factors in the history and the pathognomonic opacification of the reticulo-endothelial system are characteristic of this neoplasm. Due do the vascularity, liver biopsy may be very hazardous. Open laparotomy and biopsy seems to be less dangerous than percutaneous biopsy [5].

Differential Diagnosis List

Final Diagnosis

Thorotrast induced hepatic angiosarcoma

URL:	https://www.eurorad.org/case/810
DOI:	10.1594/EURORAD/CASE.810
ISSN:	1563-4086