Spontaneous regression of diffuse intrahepatic recurrence with portal vein tumor thrombus after resection of hepatocellular carcinoma.

We report a rare case of spontaneous regression of diffuse intrahepatic recurrence with portal vein tumor thrombus (PVTT) after resection of hepatocellular carcinoma (HCC). A 68-year-old man with hepatitis C virus-related liver cirrhosis presented with a 40 mm tumor in the right anterior segment of the liver. The tumor was diagnosed as HCC by typical imaging findings and elevated serum alpha-fetoprotein (AFP) (716 ng/ml) and protein induced by vitamin K absence II (PIVKA II) (8,100 ng/ml). A right anterior sectionectomy of the liver was performed. Microscopically, the tumor was moderately differentiated HCC. Four months after resection, a computed tomography (CT) scan showed diffuse intrahepatic recurrence with PVTT. Serum AFP was 12,319 ng/ml and PIVKA II was 168,000 ng/ml. The patient did not receive any further treatment for HCC including herbal medicine, and stopped smoking. Two years and 5 months later, no lesion was detected on a CT scan when serum AFP was 1.9 ng/ml. Ischemia due to main portal vein occlusion and rapid tumor growth might have induced tumor regression in the present case. Moreover, abstention from smoking might have improved his immunological function.