A clinicopathologic study of adenomatous hyperplasia of the liver in 209 consecutive cirrhotic livers examined by autopsy.

BACKGROUND: Adenomatous hyperplasia (AH), also called macroregenerative nodule, of the cirrhotic liver is currently considered to be a preneoplastic or early neoplastic lesion in human hepatocellular carcinogenesis.
METHODS: The authors surveyed 209 consecutive cirrhotic livers from patients who had undergone autopsy at our laboratory during the last 18 years (1974-1991), and examined the prevalence and clinicopathologic characteristics of cirrhotic livers with AH. AH was classified into two types: ordinary and atypical. Ordinary AH (OAH) is devoid of hepatocellular atypia, whereas atypical AH (AAH) consists of atypical hepatocytes equivocal as to benignity and malignancy and occasionally contains overt malignant foci.
RESULTS: A total of 123 AH were found in 45 (21.5%) of the 209 cirrhotic livers; 38 AAH were found in 12 cirrhotic livers (5.7%), and 85 OAH was found in 41 cirrhotic livers (19.6%). Nineteen AAH contained overt malignant hepatocellular foci. Comparing the first 9 years (1974-1982) with the latter 9 years (1983-1991), 4 (3.8%) of 104 cirrhotic livers harbored AAH in the first period, and 8 (7.4%) of 105 cirrhotic livers contained AAH in the latter period. Sixteen (15.4%) of 104 cirrhotic livers harbored OAH in the first period, and 25 (23.8%) of 105 cirrhotic livers contained OAH in the latter period. Etiology of the 12 cirrhotic livers with AAH was as follows: 1 was hepatitis B virus, 10 were non-A non-B hepatitis virus, and 1 was primary biliary cirrhosis. Etiology of 41 cirrhotic livers with OAH was as follows: 16 were hepatitis B virus, 18 were non-A non-B hepatitis virus, and 7 were other causes. AAH occurred commonly in mixed nodular cirrhosis, whereas OAH occurred usually in macronodular or mixed nodular cirrhosis. All 12 cirrhotic livers with AAH were associated with hepatocellular carcinoma (HCC), particularly HCC of nodular type, whereas 17 cirrhotic livers with OAH were associated with HCC and the remaining 24 cirrhotic livers with OAH were not associated with HCC.
CONCLUSIONS: These results suggest that the number of cirrhotic livers with AH is increasing gradually, and that cirrhotic livers with AAH are characterized by the association with non-A non-B hepatitis virus as well as simultaneous occurrence of HCC. Thus, AAH may be an important preneoplastic lesion in cirrhotic livers associated with non-A non-B hepatitis virus (probably hepatitis C virus).