Introduction to the 2005 long course.

Abstract

Dermatopathology, as with other fields of pathology, has undergone major changes in the last 25 years. Our understanding of epidermally derived neoplasms becomes far more advanced with each passing year. Evidence for this progress is readily apparent upon reviewing textbooks of dermatopathology over time and in examining the course contents of the long-course presentations at the United States-Canadian Academy of Pathology annual meetings. What was once a simple discussion of melanocytic neoplasms (thought to be a variant of sarcoma) has become a reasonably complex analysis of the histologic, immunologic, and molecular aspects of melanocytic neoplasia. Similarly, our understanding of the development of cutaneous squamous cell carcinoma is greatly enhanced. The understanding of the molecular alterations that result in full transformation offers great insight into carcinogenesis. This introductory essay briefly traces this progression in setting the stage for the series of more detailed chapters about epidermal neoplasms that follow.