抄録
This study used immunohistochemical staining for cytokeratin (CK) 7, 18, 19, 20, hepatocyte paraffin 1 (Hep Par 1), and albumin (Alb) to determine differences in the mechanisms by which hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), and combined hepatocellular carcinoma and cholangiocarcinoma (cHC-CC) arise. The subjects comprised 48 cases with HCC, 23 cases with ICC, and 2 cases with cHC-CC. Differences were evaluated according to marker staining intensities. Microscopic examination revealed that Hep Par 1-negative HCC was more prevalent in the poorly differentiated samples than in the well-differentiated and moderately differentiated cases (P = 0.006 and P = 0.02, respectively). Moreover, CK19-positive HCC was observed at a higher rate for the poorly differentiated types compared to the well-differentiated cases (P = 0.03). Hep Par 1-positive ICC was observed in one case, but no significant difference was observed in the staining intensity for each differentiation type in the ICC cases. These results suggested that Hep Par 1 is an effective indicator of HCC dedifferentiation, CK19 expression could be used as an index of HCC transformation, and Hep Par 1-negative/CK19-positive HCC are most likely to differentiate into biliary epithelial cells. In addition, the results suggested a high probability that some HCC transformed into ICC during the generation of cHC-CC, and that Hep Par 1-positive ICC might represent ICC that is differentiating into hepatocytes.
