[Do immunologic markers facilitate differentiation between histologic types of stomach cancer?].

Seventeen gastric carcinomas (intestinal n = 12; diffuse n = 1; mixed type n = 4) and one Barrett's carcinoma were prospectively studied by immunohistochemistry for the expression of different keratin polypeptides and of the brush border markers villin, sucrase isomaltase and aminopeptidase N. All carcinomas expressed the keratin polypeptides 8, 18, and 19 and were stained by the broad specific keratin antibody KL1, irrespective of histologic type. Keratin 7, however, was expressed in only one carcinoma in most tumor cells and in two further carcinomas in some tumor cells. Thus, specific differentiation of the various histologic types of gastric carcinoma does not seem to be aided by the use of keratin antibodies. Villin was positive in 80% of the tumors and sucrase isomaltase and aminopeptidase N were positive in 67% respectively with no obvious histologic difference. The frequent positivity of the brush border markers, usually typical for intestinal epithelium, reflects the high degree of intestinal differentiation of gastric carcinomas, but again does not seem to be associated with a particular histologic type.