This book provides new research insights on rare diseases. Chapter One reviews the use of patients' registries as a key tool in rare disease management. Chapter Two discusses the worldwide experience with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with rare abdominal and pelvic neoplasms with peritoneal metastases that should be evaluated for long-term benefit. Chapter Three explores the contribution of psychology-related research on Congenital Anomalies (CAs) from the analysis of international scientific literature.