Seven years have elapsed since the second edition of Surgical Pathology of the Head and Neckwas published. During this interval there has been an enormous amount of new information that impacts on the daily practice of surgical pathology. Nowhere is this more evident than in the area of molecular biology and genetics. Data derived from this new discipline, once considered to be of research interest only, have revolutionized the evaluation of hematolymphoid neoplasms and are now being applied, to a lesser extent, to the assessment of mesenchymal and epithelial tumors. While immunohistochemistry has been available for almost 30 years, it has not remained static. New antibodies are constantly being developed that expand our diagnostic and prognostic capabilities.