Spontaneous regression of recurrent hepatocellular carcinoma with multiple lung metastases.

Spontaneous regression (SR) of hepatocellular carcinoma (HCC) is a rare phenomenon but its true incidence is much higher than expected. We report a recurrent HCC who experienced SR both in intrahepatic lesion and lung metastasis. Serum alpha-fetoprotein decreased dramatically from more than 1000 μg/L to normal range. In addition, we reviewed 11 similar case reports published in recent 5 years. We find that the interval from diagnosis to the recognition of SR is very short (4 m, 1–14 m). Therefore, we speculate the mechanism of SR should be a severe systemic reaction, and immune activation is the most likely conjecture.