A case report of hepatocellular carcinoma within adenomatous hyperplasia: is adenomatous hyperplasia a precancerous lesion or not?

It is controversial whether adenomatous hyperplasia (AH) of the liver progresses to hepatocellular carcinoma. We experienced two hepatic lesions in a patient (73-yr-old male) with cirrhotic liver. One was diagnosed as HCC and the other was AH including a small HCC histologically. To investigate cell kinetics and the ploidy pattern of these lesions, Feulgen DNA-cytofluorometry analysis was performed. The result of this analysis suggested that AH developed into extremely well-differentiated HCC composed of mononuclear diploid cells at first and then was further transformed into clear cell type HCC composed of mononuclear tetraploid cells. The development of human HCC, at least in cirrhotic liver, may therefore be a multi-step process.