The purpose of this book is to focus on a selection of commonly tested entities, showing low to high power views. Major differences among diagnoses that are sometimes confused are emphasized on "Key Differences" pages. As a picture is worth a thousand words, text is kept to a minimum. This book is not meant to replace major textbooks of dermatopathology. Due to space considerations, the atlas is not comprehensive, and the lists of differential diagnoses in the Appendix are incomplete. Ultimately the book should be used as a companion to dermatopathology textbooks and as a pictorial reference/study tool, given that this approach is utilized by the experienced dermatopathologist when constructing examination questions. Often the major distractors are based on gestalt rather than etiology or conventional classifications. It is often the look-a-likes that are the most deceptive even though they have no obvious relationship to the correct diagnosis. This book will also be helpful to the dermatopathology novice as it introduces a simple and effective way to approach a slide