Immunoelectron microscopy in diagnostic pathology: The myths and realities of applicability and methodology

Abstract

Immunohistochemical techniques since introduction in the 1940's have held promise as ancillary methods in situations when confident diagnostic decisions could not be made using standardized histologic or histochemical methods. Recently as a result of monoclonal antibody technology and availability of reliable commercial reagents, the potential for immunohistochemistry as a diagnostic aid has been realized. Although immunologic techniques are applicable to a variety of pathological questions, particularly those related to pathogenesis and etiology, from a practical standpoint widespread use has not occurred, and diagnostic use primarily has been in the area of tumor pathology for differentiation of malignant from non-malignant tissues and for identifying antigenic differences between cancers of similar histology. At the ultrastructural level, immunocytochemistry has also received attention for use in pathology; but, as in the case of histologic use, diagnostic application at the EM level has been restricted to select well defined situations with virus identification and characterization of poorly differentiated leukemias being the major areas.