Spontaneous regression of hepatocellular carcinoma: report of a case.

A spontaneous regression of hepatocellular carcinoma is an extremely rare phenomenon. A 69-year-old Japanese man with hepatitis C virus-related chronic hepatitis presented with a liver tumor. We diagnosed the tumor to be hepatocellular carcinoma in the course of spontaneous regression, by imaging studies and changes in the tumor markers. Because the possible presence of viable cancer cells could not be ruled out, we recommended surgery. He refused all treatments at first, but finally agreed to undergo surgery about 10 months after presentation. A hepatectomy was performed. Histologically, no viable tumor cells were found. In our case, the vascularity of the tumor according to the imaging findings was followed up during the clinical course. The patient is now doing well and without any evidence of recurrence at 37 months after surgery.