Immunoperoxidase techniques applied to dermatopathology.

Immunoperoxidase techniques provide the pathologist with the capability for staining a wide range of antigens in tissue sections. More than 100 different antigens have been successfully demonstrated in fixed paraffin sections; other antigens can only be visualized in frozen sections. This latter group particularly includes lymphocyte surface antigens detectable by monoclonal antibodies. This review describes the current state of the art and provides several illustrations of the use of monoclonal antibodies for the identification of T-lymphocyte phenotypes in frozen section from cases of leprosy, mycosis fungoides, halo nevus, Kaposi's sarcoma, lichen planus and atopic dermatitis. Technical details and potential applications are discussed. The growing availability of commercial immunostaining kits makes these techniques more accessible to the surgical pathologist; indeed a whole new range of truly specific, special stains are available, as pathologists we must simply learn to use them.