Recurrent hepatocellular carcinoma after spontaneous regression

The prognosis of untreated hepatocellular carcinoma (HCC) is usually grave, although there have been a few case reports of spontaneous regression. Tumor recurrence after spontaneous regression has been rarely reported, and there have been no previous reports of recurrent hepatocellular carcinoma after spontaneous regression. Two cases of hepatocellular carcinoma that spontaneously regressed and subsequently recurred are presented. The patients' tumors spontaneously regressed, as reflected by the radiologically evidenced reduction in tumor size and markedly decreased alpha-fetoprotein levels. Subsequent tumor recurrences after regression were evidenced by radiologic findings of newly growing nodules and appreciably increased alpha-fetoprotein levels. To the authors' knowledge, these two patients represent the first reported cases of hepatocellular carcinoma recurrence after spontaneous regression. In both of these patients, new hepatocellular carcinomas recurred at different sites before the spontaneous regression of the original HCCs was complete. Although the precise causes of the regression and the subsequent recurrence remain to be further investigated, this phenomenon suggests that multicentric hepatocarcinogenicity and intratumoral events in each hepatocellular carcinoma nodule may be involved.