Paragangliomas (PGLs) are uncommon neuroendocrine tumours usually arising from sympathetic chains or parasympathetic paraganglia. Hepatic PGLs are rare, with only 12 cases described in the literature.1
We present the case of a 69-year old woman found to have a liver lesion measuring 8.2 x 5.6 cm in 1994. Originally thought to represent focal nodular hyperplasia the lesion showed progressive growth prompting concerns of hepatocellular carcinoma. Alpha-fetoprotein (AFP) was 1.3 ug/L (normal <12). 24 years after initial imaging, she underwent a liver biopsy of the 13.2 x 6.6 x 12.7 cm lesion infiltrating the right lobe of the liver demonstrated on computer tomogram (CT) and magnetic resonance imaging (MRI). The biopsy was complicated by haemorrhage leading to a large hepatic subcapsular haematoma with extensive haemoperitoneumrequiring laparotomy. Histology revealed a paraganglioma (PGL). 18F-FDG-PET-CT and 68Ga-DOTATATE-PET-CT showed intensely increased activity associated with the liver lesion and multiple lymph nodes. The patient had no clinical or biochemical evidence of catecholamine excess. A primary hepatic origin is possible as metastases were not seen on earlier CT scans. The patient is being considered for peptide receptor radionuclide therapy with 177Lutetium.
Of the 12 hepatic PGLs reported, the primary diagnosis was HCC in 6 cases. It is difficult to differentiate PGL from HCC radiologically. Similar appearances are seen on CT, MRI and PET scans, 60% of HCC showed focal tracer uptake on octreotide scans.2 One case of late uptake (> 24 hours) of metaiodobenzylguanidine has been reported in HCC.3 AFP is elevated in 70% of cases of HCC, and in 80-90% of HCC where the tumour in greater than 5cm in diameter.4 AFP has not been reported to be elevated in hepatic PGL.
Hepatic PGL should be considered with large liver tumours where AFP is normal or when there are symptoms of catecholamine excess.