P53 IMMUNOREACTIVITY IN HEPATOCELLULAR ADENOMA, FOCAL NODULAR HYPERPLASIA, CIRRHOSIS AND HEPATOCELLULAR-CARCINOMA

The prolonged half-life of mutant p53 makes feasible its immunocytoche mical detection. In order to assess the pathogenetic role of mutant p5 3 in regenerative and neoplastic liver disease we studied its immunohi stochemical expression in cases of hepatic cirrhosis, hepatocellular c arcinoma (HCC), cirrhosis with areas of HCC, hepatocellular adenoma an d focal nodular hyperplasia. The study included needle and wedge biops ies of 50 cirrhotic livers, 59 HCCs (36 of them with associated cirrho sis), six adenomas and two focal nodular hyperplasias, Sixty-five HCC fine-needle cytology specimens were also included in the study, There was no immunohistochemical evidence of mutant p53 expression in any of the cases of cirrhotic liver (except for one instance associated with HCC) adenoma or focal nodular hyperplasia. In contrast p53 was detect ed in 8.5% of HCC cases in the biopsy series and 24% of HCC cases in t he fine needle aspiration series. In addition, mutant p53 expression i n HCC was positively correlated with tumour grade. According to grade, the distribution of p53 positive immunoreactivity among HCCs was as f ollows: Grade I-II, O% of cases in the biopsy series and 9% in the fin e needle aspirates; Grade III, 18% in the biopsy series and 55% in the fine needle aspirates; and Grade IV, 40% in the biopsy series. Theref ore, mutant p53 expression does not seem to be associated with benign liver lesions but seems to correlate with the progression of HCC throu gh various grades of increasing malignancy.