BLOOD-GROUP SIALYL-TN ANTIGEN IS MORE SPECIFIC THAN TN AS A TUMOR-MARKER IN THE PANCREAS

The aim of this study was to evaluate the expression of blood group Tn and sialyl-Tn antigens in the pancreas to determine whether they coul d help to interpret histochemically needle biopsies obtained from the pancreas. Lectin and immunohistochemistry was carried out using the bi otin-labeled Vicia villosa agglutinin isolectin B4 and the mouse monoc lonal antibody MLS102 to detect the Tn and sialyl-Tn blood-group antig ens in the pancreas. All the pancreatic ductal adenocarcinomas (11/11) were positively stained by V. villosa agglutinin and MLS102 monoclona l antibody. None of the normals or chronic pancreatitics bound MLS102 monoclonal anti-body. The acini of all the normals and chronic pancrea titics were V. villosa agglutinin positive, which was absent in the no rmal ductal cells and present only sparingly in the chronic pancreatit is ductal tissues (10/16). Thus, both the Tn and the sialyl-Tn blood-g roup antigens are present in pancreatic ductal tissues that have under gone malignant transformation. MLS102 is superior to V. villosa agglut inin in distinguishing malignant from normal and nonmalignant pancreat ic tissues in needle biopsies.