Abstract

This report presents a case of an atypical nodule arising in a hepatocellular adenoma(HCA) in a non-cirrhotic liver of a 42-year-old man. The patient had been relatively healthy until he developed right upper abdominal pain. Abdominal sonography and computerized tomogram revealed a 7.5x7cm sized mass in the right inferior segment of liver. The mass revealed the histologic features of HCA. At near center of the HCA, was found a I cm sized discrete nodule, a nodule within a nodule. The nodule revealed higher cellularity than the HCA and was composed of monotonous hepatocytes with an increased nuclear-cytoplasmic ratio, resembling atypical adenomatous hyperplasia. Interestingly, the atypical nodule showed a focal pseudoacinar arrangement of tumor cells. The histologic features of the atypical nodule arising in HCA may the morphological sequence of transformation from HCA to hepatocellular carcinoma

• Keywords: Liver;Hepatocellular adenoma;Atypical nodule within a nodule;Hepatocellular carcinoma