自體免疫性胰臟炎這一個專有名詞是在西元1995年首次被提出而開始使用；起先是用來
描述一種特殊的慢性胰臟炎同時有著全身性自體免疫性疾病之表現，包括臨床上、組織學上
及實驗診斷上的特殊表現。隨著病例報告越來越多，以及日本、韓國及美國相繼訂定診斷的
標準，最近5、6年才獲得廣泛之認識與重視。如何分別自體免疫性胰臟炎和胰臟癌是很重要
的一個議題，因為自體免疫性胰臟炎的病患常不明不白，被當作胰臟癌接受大手術 (Whipple
operation)，術後發現約有2-5% 病理上毫無癌症，只有廣泛性纖維化 (diffuse fibrosis) 及淋巴球與漿胞球浸潤 (lymphoplasmacytic infiltration) 之變化。再者自體免疫性胰臟炎是可以醫治的，絕大多數對類固醇的反應都相當好，包括阻塞性黃膽、胰管狹窄以及胰臟頭部腫大均能迅速地緩解。所以如何在臨床上鑑別自體免疫性胰臟炎和胰臟癌，對臨床醫師來說是很重要的一件事。

The term autoimmune pancreatitis ( or autoimmune-related pancreatitis ) was introduced by Yoshida et al.in 1995 to describe the form of chronic pancreatitis that is associated with autoimmune manifestations revealed
on laboratory, histologic, and clinical testing. In the past 10 years, interest in autoimmune pancreatitis has grown because of an increasing ability to diagnose it with the use of new markers of disease and pancreatic biopsy as well as guidelines settled by Japan, Korea and United States. How to discriminate AIP and pancreatic cancer is
an important issue for clinicians, since the former is subjective to be controlled by medical treatment while the latter is prone to be surgically removed. Treatment of autoimmune pancreatitis with corticosteroids leads to the rapid and sustained resolution of pancreatic mass lesions, biliary obstruction, and pancreatic-duct strictures,
which has stimulated widespread interest in this condition from gastroenterologists, endoscopists, pathologists,surgeons and internal medicine practitioners.