Emergence of malignant lesions within an adenomatous hyperplastic nodule in a cirrhotic liver. Observations in five cases.

Five cases of an adenomatous hyperplastic nodule or a similar lesion resected from a cirrhotic liver in which early malignant foci were seen as small nodule-in-nodule lesions are described. These hyperplastic lesions were detected by imaging diagnosis in patients with nonalcoholic cirrhosis, mostly during routine clinical follow-up. In 2 patients, recurrence of hepatocellular carcinoma occurred 11 mo and 15 mo postresection. Thus, these nodule-in-nodule lesions in an adenomatous hyperplastic nodule seem to represent an early stage of hepatocarcinogenesis in humans. In nonalcoholic cirrhotic patients from Japan and Southeast Asia, in whom hepatocellular carcinoma is endemic, an adenomatous hyperplastic nodule or a similar hyperplastic lesion that occurs in cirrhotic livers may be preneoplastic and already committed to malignant transformation.