Nakazawa Takahiro, Ohara Hirotaka, Sano Hitoshi, Ando Tomoaki, Imai Hideto, Takada Hiroki, Hayashi Kazuki, Kitajima Yasuhiro, Joh Takashi
Department of Internal Medicine and Bioregulation, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Gastrointest Endosc. 2007 Jan;65(1):99-108. doi: 10.1016/j.gie.2006.03.929.
Autoimmune pancreatitis (AIP) presents as diffuse enlargement of the pancreas and as diffuse irregular narrowing of the main pancreatic duct. However, some AIP cases are difficult to diagnose because of atypical imaging findings.
To clarify a variety of imaging findings of AIP and the reason for its misdiagnosis.
We examined the imaging findings of 37 AIP cases and also examined misdiagnosed cases of AIP to determine their reasons for misdiagnosis.
A total of 37 patients with AIP who reported to our hospital or its affiliate over a 17-year period (1989 to May 2005).
Patients in 15 AIP cases showed segmental narrowing of the main pancreatic duct. There were 6 patients with focal enlargement of the pancreas, whereas 3 patients showed no enlargement. There were 3 cases of calcification of the pancreas. Pancreatic cysts were detected in 2 patients. Abdominal US showed multiple low-echoic masses in 1 case and a single mass in 3 cases. Sixteen patients had stenosis of the bile duct at the hilar hepatic lesion and/or the intrahepatic duct. Only 7 patients had typical AIP findings. Six patients were misdiagnosed with pancreatic cancer and 2 with bile-duct cancer. Seven cases were surgically treated. Five cases were misdiagnosed because of the nonexistence of, or the unfamiliarity with, the concept of AIP and sclerosing cholangitis with AIP. Another 3 cases were diagnosed with pancreatic cancer because of segmental stenosis of the main pancreatic duct and no or focal enlargement of the pancreas.
The results of this study suggest that AIP presents a variety of imaging findings. The most important diagnostic factor is clinician awareness of the concept of AIP and the diverse nature of imaging findings.
自身免疫性胰腺炎（AIP）表现为胰腺弥漫性肿大及主胰管弥漫性不规则狭窄。然而，部分AIP病例因影像学表现不典型而难以诊断。
阐明AIP的各种影像学表现及其误诊原因。
我们检查了37例AIP病例的影像学表现，并对AIP误诊病例进行检查以确定其误诊原因。
1989年至2005年5月期间，共有37例AIP患者到我院或其附属医院就诊。
15例AIP患者主胰管呈节段性狭窄。6例患者胰腺局限性肿大，3例患者无肿大。胰腺钙化3例。2例患者检测到胰腺囊肿。腹部超声检查发现1例患者有多个低回声肿块，3例患者有单个肿块。16例患者肝门部肝病变和/或肝内胆管处胆管狭窄。仅7例患者有典型的AIP表现。6例患者被误诊为胰腺癌，2例被误诊为胆管癌。7例患者接受了手术治疗。5例误诊是因为不存在AIP概念或对AIP合并硬化性胆管炎概念不熟悉。另外3例因主胰管节段性狭窄且胰腺无肿大或局限性肿大而被诊断为胰腺癌。
本研究结果提示，AIP有多种影像学表现。最重要的诊断因素是临床医生对AIP概念及其影像学表现多样性的认识。
