Gestational trophoblastic disease (GTD) is a distinct category of human disorders of placental trophoblast, resulting in significant morbidities in women. It is notable for its varying geographical distribution and different frequencies across age groups. In human pathology, GTD represents unique proliferative conditions of the trophoblast, characterized by distinct clinical presentations, genetic compositions, and varying biological behaviors. Since the first edition of this book, substantial new knowledge has emerged regarding the pathogenesis, diagnostic pathology, and therapeutic interventions for GTD, necessitating an update. This second edition will incorporate these advancements, focusing on key themes such as the current understanding of the molecular pathogenesis of gestational trophoblastic disease, new classifications and disease entities introduced by the WHO, refined diagnostic criteria, recent immunohistochemical biomarkers for both diagnostic and therapeutic applications, molecular genotyping analysis of GTD, and novel clinical therapeutic interventions, including modern immunotherapy for patients with high-risk gestational trophoblastic neoplasms. Like the first edition, this comprehensive book emphasizes diagnostic pathology and the genetic aspects of the disease. The second edition will feature an enriched collection of diagnostically challenging cases of trophoblastic specimens curated from the author's personal consultation practice over the past decade. Gestational Trophoblastic Disease: Diagnostic and Molecular Genetic Pathology, 2nd Edition is written for a broad audience in diagnostic pathology, including specialty gynecologic pathologists, general pathologists, molecular pathologists, and pathologists-in-training. Contributions from leading experts offer diverse perspectives and valuable insights, making this text a robust resource for pathologists, clinicians, and researchers navigating the complexities of GTD. The book is ideal for organizing diagnostic pathology training courses on gestational trophoblastic disease. It also serves as a valuable reference for scientific investigators interested in trophoblastic disorders and the genetic/epigenetic regulation of placental trophoblast development and function. As new discoveries continue to reshape our understanding of GTD, we hope this edition serves as a bridge between current knowledge and future innovations, offering both a practical guide and an inspiring resource for advancing GTD diagnosis, treatment and research.