[Skull metastasis of hepatocellular carcinoma: case report]

We report a case of skull metastasis from a hepatocellular carcinoma (HCC). A 68-year-old male with hepatitis C virus-associated cirrhosis and HCC presented with painless subcutaneous mass in the left frontotemporal region. Radiologically, skull X-ray showed an osteolytic lesion, and non-contrast CT displayed a hyperdense tumor that homogeneously enhanced on contrast CT. Cerebral angiography demonstrated a hypervascular mass with the feeding arteries from the external carotid artery. The tumor was shown as an iso-intensity mass with flow voids on T1WI, as iso- to hypo- intensity on T2WI and FLAIR images, and as hypo-intensity on DWI. The lesion was markedly enhanced by Gd-DTPA. Previous reports have described a low incidence of skull metastasis in HCC patients. However, the incidence is gradually increasing due to the prolonged survival rates of HCC patients, indicating the significance of the disease as a differencial diagnosis for skull tumors. Recent reports describe characteristic MRI findings of skull metastasis from HCC (hypointensity on T2WI with flow void); however, owing to the rarity of this disease, more studies are needed to establish the typical MRI pathognomonic findings.