Advances in molecular and genetics based diagnostics, are driving an increased interest in cytopathology as cytological specimens are the ideal substrate for this new technology. Although there are a handful of comprehensive, standard texts on the market, there is a need for portable, more concise books for easy reference. Thus, the inception of the new Essentials in Cytopathology series is intended to fill the gap in the market. This Series will fulfill the need for an easy-to-use and authoritative synopsis of site-specific topics in cytopathology. The discussions will take into account the need for increased emphasis on differential diagnoses, the how-to's on screening, cytology/hitology correlation, what the criteria are, as well as issues involved with patient interaction, such as on-site evaluation. Discussions will address safety issues as well as diagnostic pitfalls. Each volume will be site-specific and edited by leading specialists in the field. These guide books fit into the lab coat pocket, ideal for portability and quick reference. Each volume will be heavily illustrated with a 125-image full color art program, while the text will follow a user friendly outline format. A must- have for every pathologist, cytopathologist, fellow and trainee. The inaugural volume of the Series will be the Thyroid, edited by Drs. Clark and Faquin, leaders in the field of thyroid cytopathology.