Immunohistochemistry in diagnostic dermatopathology.

Immunopathology continues to be important in diagnostic dermatopathology. Immunopathology is an invaluable tool for assessing the tissue of origin or direction of differentiation of cells. In some cases this can result in a more precise diagnosis. This article reviews the role of immunopathology in determining the biologic behavior of hematolymphoid infiltrates. It explores the methodology of immunoperoxidase, discusses the most commonly used antibody reagents, and presents a series of diagnostic dilemmas in which immunopathology can be useful. In each case a strategy is established that maximizes the likelihood of making a definitive diagnosis.