[Pathology of hepatocellular carcinoma: recent update].

In recent years, growing number of literatures have supported the concept that large nodules usually found in cirrhotic livers represent premalignant lesions in the setting of chronic liver disease. With the use of advanced imaging techniques, nodules suspicious for malignancy have often been identified and resected. While some resected lesions were found to be small hepatocellular carcinomas (HCCs), others were not. Some of these non-malignant nodules were devoid of atypia, some had architectural or cytological atypia insufficient for a diagnosis of HCC though they are suggestive of a premalignant state, while others contained microscopic subnodules of HCC. In follow-up studies and series of explants from liver transplant centers, the occasional finding of microscopic foci of HCC in the nodules was confirmed and significant associations with HCC elsewhere in the same liver were established. Such findings suggested that these nodular lesions, which are referred as "dysplastic nodules" (or adenomatous hyperplasia), are probably a frequent pathway in human hepatocarcinogenesis. We discuss the pathological characteristics of dysplastic nodules and small HCCs.