Immunohistochemistry in mohs micrographic surgery: a review of the literature.

Mohs micrographic surgery has become the "gold standard" for surgical excision of nonmelanoma skin cancers for maximal preservation of normal tissue. Mohs micrographic surgery entails processing specimens in horizontal frozen sections with immediate examination under a light microscope. This technique offers the examination of lateral and deep margins in the same plane in contrast to wide local excision. Success with Mohs micrographic surgery depends on accurate mapping of the tumor, correct interpretation of the histopathological sections, and appreciation of aggressive tumor characteristics. The most common reason for recurrence of tumor after Mohs micrographic surgery is residual undetected tumor. Because hematoxylin and eosin stains may present difficulties in interpretation, immunohistochemistry techniques are being used to supplement these routine stains. Although immunohistochemistry is not being widely utilized by Mohs micrographic surgery surgeons, the many advantages of immunohistochemistry over routine staining of frozen sections in selected settings is of great value. Herein, the authors review the application of immunohistochemistry in Mohs micrographic surgery for a variety of neoplasms encountered most frequently by Mohs micrographic surgery surgeons. (J Clin Aesthetic Dermatol. 2009;2(7):37-42.).