Direct tissue visualization of normal cross-reacting antigen in neoplastic granulocytes

Normal cross-reacting antigen, a glycoprotein that shares some antigenic determinants with carcinoembryonic antigen, was consistently demonstrated by tissue immunoperoxidase staining in the cytoplasm of both non-neoplastic and neoplastic neutrophilic granulocytes. It was absent in lymphoid cells, but occasional cells of the macrophage/histiocyte series showed variable staining. Malignant cells from patients who had non-Hodgkin or Hodgkin lymphomas were negative for normal cross-reacting antigen. These findings were in contrast to the findings of specific normal cross-reacting antigen positivity in neoplastic granulocytes from three patients who had acute granulocytic leukemia, three who had chronic granulocytic leukemia, and one who had a granulocytic sarcoma. Similar normal cross-reacting antigen positivity was also seen in granulocytes from two patients who had granulocyte dysplasia. It is suggested that direct tissue visualization of normal cross-reacting antigen using immunoperoxidase technics may be of value in the classification and diagnosis of hematologic malignancies, and may provide an additional marker for cells of the granulocytic series.