Intraepithelial neoplasia (IEN) are some kind of preinvasive lesions. The definition and identification of intraepithelial neoplasia is exceedingly important for early diagnosis and prevention of malignancy. This book introduces for the first time the concept of intraepithelial neoplasia for the entire body in detail and the diagnostic applications of intraepithelial neoplasia in many organs and systems – including the respiratory and digestive systems, pancreas, bile duct, breast, prostate, urinary system, female genital system and the skin. The book features a large number of original figures – 450 – from Chinese patients with detailed descriptions. The book can serve as a diagnostic reference and as a research guide to preinvasive lesions for pathologists, oncologists and scientists. In addition, it will be able to help medical and pathology students improve their understanding of early neoplasia.