Spontaneous Regression of a Poorly Differentiated Hepatocellular Carcinoma: A Case Report

Abstract

Hepatocellular carcinoma (HCC) is the most common histological type of primary liver cancer, and spontaneous regression of HCC is rare. We report the case of a 76-year-old male diagnosed with poorly differentiated HCC that spontaneously regressed. Although the patient did not undergo any treatment or invasive diagnostic tests, such as angiography, before surgery, the resected tumor showed complete necrosis similar to that seen after transcatheter arterial embolization. The main cause of the necrosis in the present case was thought to be the occlusion of nutrient vessels and tumor hypoxia. Tumor hypoxia and immunological reactions are reported to be the main causes of spontaneous HCC regression, although the underlying mechanisms remain unclear. In this case report, we provide additional insights into this phenomenon.