From the Preface: '...This edition represents a significant expansion of both the textual and illustrative material of the Third Series Fascicle. The numerous images reflect our belief that the 'atlas' role that was the intent of the original fascicles of the Armed Forces Institute of Pathology is of paramount importance in these works. At the same time the current scope is no longer primarily a visual resource but also a comprehensive description of clinical, pathologic, immunohistochemical, molecular biologic, prognostic and to a limited extent, therapeutic aspects of the various entities. For this reason we have greatly expanded our coverage of the immunohistochemical and molecular features of the various lesions, recognizing that such information is quickly supplemented be new observations. Nevertheless we continue to believe that careful gross examination and routine light microscopic observations are the foundations for diagnosis of these neoplasms and neoplastic-like processes...'.