Intrahepatic distant metastasis and metachronous multicentric occurrence in solitary hepatocellular carcinoma of less than five centimeters in diameter.

During the 7 years from 1984 to 1990, 36 patients underwent liver resection for solitary hepatocellular carcinoma (HCC) measuring less than 5 cm in diameter, with no intrahepatic vascular invasion on imaging diagnoses and no macroscopic infiltration into the tumor capsule or surrounding tissues. Although HCC is less likely to cause intrahepatic adjacent metastasis to the cut liver surface, an analysis revealed the possibility of intrahepatic distant metastasis and metachronous multicentric occurrences, even after complete removal of the primary tumor. The 5-year cumulative survival rate was 53%, while the 5-year cumulative recurrence-free survival rate was 19%. Of the 36 patients, 18 (50%) had suffered a recurrence by April, 1992, one with extrahepatic metastasis. Recurrence of intrahepatic metastasis was multifocal in 5 patients, single and adjacent in 1, and single (or a few) and distant in 11. Multifocal recurrence was observed within 1 year after liver resection. The sole single and adjacent metastatic case occurred in one of eight patients in the recurrent group in whom distance of the surgical margin was less than 1 cm [TW(+)]. Multicentric occurrence was found in 6 of 13 patients (46%) whose recurrent tumors were examined histologically, and all belonged to the "single (or a few) and distant" type of recurrence. In this report, we also present two typical cases of metastasis, one being multifocal metastasis occurring within 3 months after liver resection and the other being intrahepatic metastasis occurring after a 4-year-dormant state, to demonstrate the complicated nature of the intrahepatic metastatic pattern.