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 to help train the eye to rapidly notice distinctive features. As a picture is worth a thousand words, text is kept to a minimum. This 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 lookalikes 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, and to that end, common diagnoses have been specifically included (i.e. actinic keratosis, basal cell carcinoma).