Immunohistochemistry in dermatopathology: a review of the most commonly used antibodies (part I).

Dermatopathology includes a long list of disorders, some of which have very similar histopathology. Immunohistochemistry is an important auxiliary tool for diagnosis and differential diagnosis, and for predicting the outcome of many skin tumors. It is also the main technique for determining the origin of a tissue or the differentiation of neoplastic cells. In many cases, immunohistochemistry provides a more accurate diagnosis of the different processes that infiltrate the skin. This review examines the role of immunohistochemistry in studying the differentiation and biological behavior of the majority of tumors that can involve the skin. We review the immunoperoxidase techniques, discuss the utility of the most commonly used antibodies, and highlight a number of diagnostic problems in which immunohistochemistry may be very useful. In each case, the goal is to reach a specific and definitive diagnosis. In the first part of this review, we examine the antibodies that determine the different cell-differentiation profiles of skin tumors.