自身免疫性胰腺炎的内镜诊断方法
2016/7/3 医学界消化频道

    

     内镜在自身免疫性胰腺炎诊治中有哪些作用?本文为你点评。

     作者:厦门大学附属中山医院 胡益群

     来源:海峡消化

     摘要

     自身免疫性胰腺炎(AIP)主要特征是弥漫性胰腺增大和主胰管不规则狭窄。免疫球蛋白IgG4相关硬化性胆管炎(IgG4-SC)与AIP都经常显示为胆管狭窄。因此,将AIP、IgG4-SC和胰腺癌、胆管癌或原发性硬化性胆管炎鉴别开来非常重要。

     内镜在AIP和IgG4 SC中起了非常重要的作用,因为它能够呈现主胰管和胆管狭窄的影像表现,而且能够通过其获得组织样本进行组织学评估。内镜逆行胰胆管造影(ERCP)提示主胰管弥漫性不规则狭窄对AIP诊断具有特异性,但是主胰管局部狭窄往往与胰腺癌很难鉴别。

     一个长的狭窄(大于主胰管1/ 3长度)和缺乏上游扩张的狭窄(小于5毫米)可能ERCP影像提示AIP的关键特征。一些胆管的特征,如节段性狭窄,低位胆管狭窄和狭窄前扩张伴随较长狭窄,在IgG4-SC中比胆管癌更常见。

     在AIP中,超声内镜(EUS)显示弥漫性低回声胰腺肿大,有时伴有低回声团块影。此外,超声弹性成像和谐波增强超声内镜已展现出非常有前景的结果。

     超声内镜引导下细针穿刺可以通过获得充分的组织来用于AIP的诊断,对此人们已达成越来越多的共识。将来,内镜程序和设备的改进将有助于为了更准确的诊断AIPand IgG4-SC。

     点评

     自身免疫性胰腺炎(AIP)近些年来逐渐被人们所认识,西方国家有较高的发病率,我国近些年来自身免疫性胰腺炎发病率也是逐年升高,其临床特点为血清γ-球蛋白或免疫球蛋白(Ig)G水平升高。

     自身抗体的存在,弥漫性、不规则主胰管的狭窄和扩张,偶有下部胆管狭窄,伴随有其他自身免疫性疾病,症状较轻,进展缓慢,通常没有胰腺炎急性发作,类固醇激素治疗有效性,组织学表现淋巴浆细胞性硬化性胰腺炎。目前AIP可分为两种类型。

     目前一种观点认为,AIP是IgG4相关硬化性胆管炎(IgG4-SC)表现的组成部分。

     AIP诊断存在难题,很难与IgG4-SC和胰腺癌、胆管癌或原发性硬化性胆管炎鉴别,常出现误诊,提高AIP的诊断率,尤其是不典型AIP,与恶性疾病的鉴别,迫切需要一些新的方法和技术支持。

     内镜在鉴别诊断方面发挥了非常大的作用,超声内镜,ERCP,超声内镜弹性成像技术,胰管胆管内内超声,尤其是EUS-FNA可作为自身免疫性胰腺炎诊断和鉴别诊断的有力手段,但是其诊断图像的识别和特点归纳,还需要不断的总结。

     AIP和IgG4-SC诊断的金标准是以组织学为基础,尤其是在与恶性占位无法区分的时候,目前获得病理的手段主要是EUS-FNA,有一定的局限性,当病变较小,取材困难时,迫切需要一些新的技术方法,在不远的将来,随着科学的进步,各种内窥镜设备的研发,取得胰腺病理组织能力会大大提高,而且更加有效、安全,AIP诊断水平也会随之获得新的飞跃。

     Endoscopicapproaches for the diagnosis ofautoimmune pancreatitis

     Abstract

     Autoimmunepancreatitis (AIP) is characterized by diffuse pancreaticenlargement andirregular narrowing of the main pancreaticduct (MPD).

     Immunoglobulin(Ig)G4-related sclerosing cholangitis(IgG4-SC) associated with AIP frequentlyappears as a bile ductstricture. Therefore, it is important to differentiateAIP andIgG4-SC from pancreatic cancer and cholangiocarcinoma or primarysclerosingcholangitis, respectively.

     Endoscopy plays acentral role in the diagnosis ofAIP and IgG4-SC because it providesimaging of the MPD and bile duct stricturesaswell as the ability toobtain tissue samples for histological evaluations.

     Diffuseirregularnarrowing of MPD on endoscopic retrogradecholangiopancreatography(ERCP) is rather specific to AIP, butlocalizednarrowing of the MPD is often difficult to differentiate fromMPDstenosis caused by pancreatic cancer. A long stricture (>1/3the lengthof the MPD) and lack of upstream dilatation from thestricture (<5 mm) might bekey features of AIP on ERCP.

     Somecholangiographic features, such as segmentalstrictures, stricturesof the lower bile duct, and long strictures withprestenoticdilatation, are more common in IgG4-SC than incholangiocarcinoma.Endoscopic ultrasonography (EUS) reveals diffusehypoechoicpancreatic enlargement, sometimes with hypoechoicinclusions, in patients withAIP.

     In addition, EUS-elastography andcontrast-enhanced harmonic EUS have beendeveloped withpromising results. The usefulness of EUS-guided fine-needleaspirationhas been increasingly recognized for obtaining adequatetissue samplesfor the histological diagnosis of AIP. Furtherimprovement of endoscopicprocedures and devices will contributeto more accurate diagnosis of AIP andIgG4-SC.

     -----Digestive Endoscopy 2015; 27:250–258 doi: 10.1111

     参考文献

     1.Kozoriz MG, Chandler TM, Patel R, Zwirewich CV, Harris AC.Pancreaticand Extrapancreatic Features in Autoimmune Pancreatitis.Can Assoc Radiol J. 2015 May 7.pii: S0846-5371(14)00119-3.doi: 10.1016/j.carj.2014.10.001.2.Lin J, Cummings OW, Greenson JK, House MG, Liu X, Nalbantoglu I, Pai R, Davidson DD, Reuss SA.IgG4-related sclerosing cholangitis in the absence of autoimmunepancreatitis mimicking extrahepaticcholangiocarcinoma.Scand JGastroenterol. 2015 Apr;50(4):447-53. doi: 10.3109/00365521.2014.962603.Epub 2015 Jan 30.

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