Spontaneous neoplastic remission of hepatocellular carcinoma

We report on a case of a 57-year-old male who underwent a curative resection for hepatocellular carcinoma (HCC) with histological confirmation of a spontaneously necrotized tumor. Initial serum AFP level was 4,778 ng/mL. A 3.7 cm hyperechoic mass in segment 6 of the liver was observed on ultrasonography and dynamic contrast-enhanced liver MRI showed a 3.7 × 3.1 cm sized HCC. He was scheduled to undergo curative surgical resection under the clinical diagnosis of an early stage HCC (Barcelona Clinic Liver Cancer stage A). Without treatment, the serum AFP level declined rapidly to 50 ng/mL over five weeks. He underwent curative wedge resection of segment 6 of the liver. Histology revealed complete necrosis of the mass rimmed by inflamed fibrous capsule on a background of HBV-related cirrhosis with infiltration of lymphoplasma cells. Exact pathophysiology underlying this event is unknown. Among the proposed mechanisms of spontaneous neoplastic remission of HCC, circulatory disturbance and activation of host immune response offer the most scientific explanation for the complete histologic necrosis of HCC in the resected mass seen in our patient.