Spontaneous regression of hepatocellular carcinoma: two case reports and a literature review.

Spontaneous regression of a malignant tumor is extremely rare. Here we report two cases of spontaneous regression of hepatocellular carcinoma (HCC), and review the associated literature. Case 1 was a 77-year-old male with HCC in the right lobe and multiple lung metastases. alpha-fetoprotein (AFP) and protein induced by vitamin K deficiency or antagonist II (PIVKA-II) were >50,000ng/ml and 21,500mAU/ml, respectively. He and his family refused further treatment, and he was discharged. Four months after the diagnosis, dramatic diminution of HCC and lung metastases was noted, and the HCC had disappeared completely 12 months later. Case 2 was a 72-year-old male with multiple nodular regions with enhanced circumference in the right lobe, the largest of which was 8cm in diameter, referred to the gastroenterology unit of our hospital. Laboratory analyses showed positive for hepatitis C virus antibody, and AFP and PIVKA-II were 936.3ng/ml and 2,380mAU/ml, respectively. However, he and his family refused further treatment, and he was followed-up as an outpatient by a local clinic. Two years later, radiological investigations revealed remarkable regression of HCC. Laboratory analyses showed that PIVKA-II had decreased to the normal range, while AFP had increased to double the original value.