Application of immunochemistry to the diagnosis of human neoplasms in routine histologic sections.

The application of immunostaining techniques to the study of sections of formalin-fixed, paraffin-embedded tissues has deeply influenced the practice of surgical pathology of tumors. We have favored in our laboratory the avidin-biotin complex immunoperoxidase method and have gradually substituted monoclonal antibodies for polyclonal sera. Better results are sometimes obtained with trypsinization prior to the application of the primary antibody. The more common primary antibodies used are directed against the following categories of cellular antigens: intermediate filaments, oncofetal products, hormones or hormone-related peptides, enzymes or enzyme-related peptides, cell- or tissue-"specific" products, lymphocyte-leukocyte antigens, and immunoglobulin chains. Controls are essential to every immunohistochemical reaction. Because of the pitfalls of immunohistochemical techniques, immunohistochemistry as applied to the study of tumors should be used with utmost care and as an extension of routine surgical pathology.