IgG4-related disease is a new systemic disease that has only recently been identified and characterized. However, most clinical practitioners are not yet familiar with it and thus are likely to misdiagnose it. The purpose of this book is to raise awareness of this disease and its diagnostic pitfalls. A wealth of radiological and histopathological images helps clinicians to understand its characteristics in various organs as well as their clinical and basic medical backgrounds. All of the authors are experts who have published numerous important papers in the field. This book will be useful to physicians in various disciplines such as gastroenterology, rheumatology, ophthalmology, otolaryngology, urology, hematology, and respiratory medicine, not only as a textbook but as an authoritative and comprehensive reference work as well.