Pathobiology of selected tumors of the base of the skull.

Skull base surgery is a new subspeciality, and, up to this point, most articles on this subject have focused on innovative operative-reconstructive approaches to tumors in this region. It is now important that we embark on a new era, the era of tumor biology, and concentrate on new ways of evaluating these neoplasms from a pathologic viewpoint. The hematoxylin-cosin section is no longer an end point, but just a beginning. This is the age of molecular biology. It is important that these tumors be evaluated, either prospectively or retrospectively, employing immunohistochemical staining, flow cytometry, oncogene expression, cytogenetics, or other techniques in order to identify important prognostic features. Data from these additional studies may then be used to develop new treatment strategies. Skull base societies should develop protocols for one or more of these tumors to ensure that they are indeed evaluated uniformly. In this article I emphasize the importance of accurate histologic classification or subclassification of these neoplasms and focus on contemporary parameters that may or may not impact on prognosis.