The thymus gland has always fascinated me and, despite the ever-growing abun­ dance of medical books, this subject seemed to be a bit of a "poor relation." As a surgeon, the lack of information was particularly frustrating, and this is why I de­ cided to edit a text covering the different aspects of thymic pathology, surgery, and prognosis. It is always difficult to strike a balance between what is to be included and left out of a book about a subject intended for readers of different specialities. This one was written primarily to provide valuable information to surgeons on most aspects related to thymic surgery and to other specialists who are often confront­ ed with thymic diseases. Written by leaders in their respective fields, I hope it will provide an excellent reference for those interested in an up-to-date synthesis of general knowledge of such highly specialized areas as immunology, pathology, and neuroscience. The opening chapters on clinical management provide a historical review and descriptions of the normal thymus and surgical pathology. Later chapters review the various diseases related to the surgical pathology of the thymus. Investiga­ tions, surgical procedures, and other therapeutic modalities are also extensively covered. The book closes with chapters on the postoperative evolution of myas­ thenia gravis and thymic tumors, as well as on the effect of thymectomy in hu­ man oncogenesis.