An immunohistochemical survey of amylase isoenzymes in cholangiocarcinoma and hepatocellular carcinoma.
It is well known that neoplastic cells of several organs produce amylases. However, to our knowledge, alpha-amylase expression has not been reported in hepatic neoplasms. In the present study, we surveyed the expression of alpha-amylase isoenzymes in cholangiocarcinoma (CCC) (n = 18) and hepatocellular carcinoma (n = 20) by an immunohistochemical technique, using four polyclonal and monoclonal antibodies against salivary- and pancreatic-type amylases. In CCC, salivary- and pancreatic-type amylase immunoreactivity was found in the tumor cell cytoplasm in 11 (61%) and eight (44%) cases, respectively. There was a tendency for salivary- and pancreatic-type amylases to appear in the same CCC. The proportion of isoamylase-positive cases was high in well-differentiated CCC (75%), intermediate in moderately differentiated CCC (66%), and low in poorly differentiated CCC (25%). In contrast, hepatocellular carcinoma cells were negative for salivary- and pancreatic-type amylases. Intrahepatic large bile ducts of nontumorous areas frequently expressed both amylase isoenzymes, while nonneoplastic hepatocytes were negative for both isoamylases. These results suggest that biliary epithelial cells retain amylase isoenzymes after malignant transformation. The finding that the expression of amylase isoenzymes was correlated with the histologic differentiation in CCC supports this suggestion.
Second Department of Pathology, Kanazawa University School of Medicine, Japan.
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Terada
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Nakanuma
D002759:Adenoma, Bile Duct / Q000201:enzymology*; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000201:enzymology; D001653:Bile Ducts, Intrahepatic; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000378:metabolism*; D008113:Liver Neoplasms / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D000516:alpha-Amylases / Q000378:metabolism*
D007527:Isoenzymes; D000516:alpha-Amylases