Introduction

Abstract

Molecular diagnostics is a rapidly evolving field, becoming more pervasive in all disciplines of medicine, including dermatology. Molecular testing is now incorporated into all aspects of patient management, including diagnostics (identifying and classifying disease), prognostics (predicting disease course), and theranostics (predicting response to therapy). For example, molecular tests are now used to help identify germline mutations in the genodermatoses, somatic mutations in tumors such as melanoma and various sarcomas, and the presence of certain cutaneous infectious agents. For melanoma and lymphoma, testing can potentially predict tumor behavior and modify patient staging. And, regarding theranostics, there is no better impactful example in dermatology than the recent observation that targeted therapy to the mutated B-Raf^V600E in a subset of melanoma patients dramatically reduces tumor burden and, in rare cases, leads to apparent cure. As molecular testing continues its trend toward higher utilization and the generation of massive amounts of data, which are often beyond our current medical comprehension, understanding the appropriate use of testing and interpretation of primary data have become essential components in the management of the individual patient. The following chapters provide a discussion of the current and near-future state of affairs of molecular diagnostics in the context of the dermatology patient, along with practical advice for those ordering tests and interpreting results.