Frequent occurrence of hepatocellular carcinoma in cirrhotic livers after surgical resection of atypical adenomatous hyperplasia (borderline hepatocellular lesion): a follow-up study.

OBJECTIVES: Adenomatous hyperplasia (AH) of the liver occurs in chronic advanced liver diseases, and has been suspected to be a precancerous lesions in human hepatocarcinogenesis.
METHODS: In this study, the incidence of hepatocellular carcinoma (HCC) after surgical resection of AH was evaluated in 24 patients with cirrhosis and AH in the absence of HCC (mean follow-up period, 31.4 months; range, 12-77 months). AH were classified as ordinary AH lacking hepatocellular atypia (OAH), atypical AH with structural and cellular atypia insufficient for carcinoma (AAH), and atypical AH with focal malignancy containing areas of HCC (FM).
RESULTS: HCC was noted in a few years (follow-up period range, 12-77 months; mean, 31.4 months) in all 3 patients whose resected nodules were classified as FM, in 4 (36%) of 11 with AAH resected nodules, and none of 10 with OAH resected nodules. The incidence of HCC in the patients with FM or AAH nodules was significantly higher than that in those with OAH nodules.
CONCLUSIONS: These results suggest that our classification of AH is useful in the assessment of the risk of HCC in patients with cirrhosis and AH, and that those with AAH or FM resected nodules must be followed up more frequently than those with OAH nodules, because of their higher risk of HCC. The frequent occurrence of HCC after resection of FM or AAH nodules may imply that HCC is of multicentric origin.