Hepatic vein tumor thrombosis in patients with hepatocellular carcinoma: Prevalence and clinical significance.

HVTT may be more common than typically reported. In most patients, it was accompanied by PVTT. Isolated HVTT occurred less frequently and later than isolated PVTT; however, once developed, it had the same deleterious impact on survival. Therefore, patients with HVTT should be classified as advanced stage of HCC.