自身免疫性胰腺炎

The purpose of this review is to provide a concise view of the existing knowledge of autoimmune pancreatitis (AIP) for practicing clinicians.AIP is a rare disease whose recognition and understanding are evolving.It is a type of chronic pancreatitis which often presents as obstructive jaundice,has a distinctive histology and is exquisitely sensitive to steroid therapy.This form of chronic pancreatitis has a unique clinical,biochemical,and radiological profile.The term “AIP” encompasses two subtypes:type 1 and type 2.Type 1 AIP is the pancreatic manifestation of a systemic fibro-inflammatory disease called IgG4 associated systemic diseases; type 2 AIP has been shown to be associated with inflammatory bowel disease.Existing criteria are geared towards the diagnosis of type 1 AIP.At present,pancreatic histology is a requirement for the definitive diagnosis of type 2 AIP.AIP can mimic most other pancreatic diseases in its presentation,but in clinical practice it often has to be differentiated from pancreatic cancer.There are established criteria and algorithms not only to diagnose AIP but also differentiate it from pancreatic cancer.The utility of these algorithms and the approach to management are discussed here.     

自身免疫性胰腺炎

自身免疫性胰腺炎（autoimmune pancreatitis,AIP）是一种少见而特殊的慢性胰腺炎。尽管Sarles领导的法国科学团队于1961年发表了第1篇关于自身免疫对胰腺影响的报道,但直到1995年AIP这个概念才为人所知。2001年,Hamano等里程碑式地阐述了AIP与免疫球蛋白（immunoglobulin,Ig）G4抗体的关系,     

自身免疫性胰腺炎的诊治分析：附2例报告

背景与目的 自身免疫性胰腺炎（AIP）是一种由自身免疫介导的罕见胰腺炎,发病率约10.1/10万,皮质激素治疗效果良好。但部分局灶性AIP与胰腺癌较难鉴别,也存在误诊为胰腺癌而采取手术治疗的情况。目前,AIP的发病机制尚未阐明,相关研究仍然缺乏。本文报告本中心近期收治的2例1型AIP患者的诊治过程,并结合文献进行复习以期为临床工作提供借鉴。方法 回顾性分析中南大学湘雅三医院胆胰外科收治的2例1型AIP患者的临床资料,并复习相关文献,对该病的临床特点和治疗决策进行分析总结。结果 2例患者均为男性,表现为梗阻性黄疸,影像学检查均提示胰头部占位,难以区分炎症及肿瘤。患者1血IgG4显著升高,伴有胰腺外器官受累的表现,诊断为1型AIP,激素治疗后病情缓解。患者2相对不典型,无血IgG4和胰外器官受累等表现,超声内镜穿刺病理回报慢性炎症,为进一步诊治行腹腔镜下胰十二指肠切除术,术中可见胰头明显肿大,质地硬,与周围粘连紧密。术后病理呈典型的淋巴浆细胞硬化性胰腺炎（LPSP）,诊断为1型AIP,激素治疗后病情缓解。结论 对于胰腺占位可疑胰腺恶性肿瘤的患者,要时刻考虑到AIP的可能,完善免疫标志物等检查。典型病例一般诊断不难,而不典型病例则可能需要手术切除后才能最终诊断,对于中老年男性、肿瘤标志物正常或轻度升高、穿刺病理阴性的患者,良性占位的可能性大,应密切关注术后病理,如诊断为AIP,需告知患者尽早接受规范的内科治疗。     

自身免疫性胰腺炎的诊断

自身免疫性胰腺炎（AIP）是由自身免疫介导,以梗阻性黄疸、胰腺肿大、胰管不规则狭窄、淋巴浆细胞浸润并纤维化、伴或不伴胰外器官受累为特征．对激素治疗敏感的一种特殊类型的慢性胰腺炎。临床上AIP诊断十分困难,且临床及病理医师对其亦认识不足,误诊率较高。因AIP常以梗阻性黄疸、胰腺肿大为特征,故易误诊为胰腺肿瘤而采取不必要的手术切除。增加对AIP的认识,提高诊断正确率,对改善AIP的诊断现状和治疗水平尤为重要。     

Recognition of other organ involvement might assist in the differential diagnosis of IgG4-associated sclerosing cholangitis without apparent pancreatic involvement: report of two cases

IgG4-associated sclerosing cholangitis (IAC) was recently defined as biliary involvement of IgG4-related systemic disease. It is frequently associated with autoimmune pancreatitis, characterized by pancreatic enlargement and irregular narrowing of the pancreatic duct. However, a few cases of IAC with no apparent pancreatic involvement have been described, the characteristics of which may mimic those of cholangiocarcinoma. We report two rare cases of IgG4-associated sclerosing cholangitis at the hepatic hilum, mimicking hilar cholangiocarcinoma. When trying to establish the diagnosis, we should consider other organs that could be involved, such as the pancreas, salivary glands, retroperitoneum, lymph nodes, and kidneys, as well as chronic inflammatory changes. By recognizing these lesions and measuring serum IgG4, IAC can be diagnosed correctly, thereby avoiding unnecessary major surgery for a condition that is treated effectively by steroid therapy.     

A rare case of IgG4-related systemic disease manifesting with pancreatic head mass mimicking borderline resectable cancer

INTRODUCTION

Autoimmune pancreatitis (AIP) is a rare pancreatic disorder among chronic pancreatitis that can mimick pancreatic cancer (PC). Patients with type 1 AIP usually present obstructive jaundice associated with high level of IgG4 in serum and a pancreatic mass at radiological imaging; these disorders may be associated with other organs lesions presenting the same histopathological features, and in these cases AIP should be considered a pancreatic localization of an IgG4-related systemic disease.

PRESENTATION OF CASE

We report the case of a young man with initial suspect of PC to be treated with surgery, and final diagnosis of AIP in the context of an IgG4-related systemic disease.

DISCUSSION

Because of its similar features, several algorithms have been proposed for AIP diagnosis, based on combination of clinical/serological and radiological criteria. However, histology represents the only way to obtain definitive diagnosis, even if sometimes it is difficult to obtain biological samples.

CONCLUSION

IgG4-related systemic disease must be taken into account among differential diagnosis during the workup for PC, in order to avoid unnecessary surgery.     

自身免疫性胰腺炎22例临床诊治分析

目的 探索自身免疫性胰腺炎（AIP）的临床特点及诊疗方法。方法 回顾性分析2017年9月至2020年7月在复旦大学附属中山医院胰腺外科诊治的22例AIP病人临床资料。通过记录分析AIP病人初诊及治疗阶段的临床表现,血清IgG4变化情况等辅助检查结果,激素治疗等情况,探索其诊治策略。结果 病人最初就诊时血清IgG4中位数为5.56（0.34～30.30）g/L,其中单纯胰腺受累者2.52（0.34～5.73）g/L,合并其他器官受累者7.59（0.66～30.30）g/L,合并胰腺外器官受累的AIP病人IgG4水平高于单纯胰腺受累的AIP病人（Z= 5.693,P=0.045）;22例病人中有9例接受激素治疗,治疗期间IgG4水平 3.7 （0.99,18.3）g/L,激素治疗2个月后IgG4水平中位数1.63（0.76,8.31）g/L,较未行激素治疗时明显下降（Z=-2.093,P=0.038）。8例病人（激素治疗5例,未激素治疗3例）复发时,IgG4较前均有不同程度升高（8/8,100%）,中位升高数值4.14（0.61,14.81）g/L;4例停药病人中,2例病人IgG4水平未恢复到正常（2/4,50%）。另有13例病人未接受激素治疗,治疗随访时10例（10/13,76.9%）病人处于临床缓解期。结论 在AIP病人中,血清IgG4在多器官受累时升高更为显著。使用激素治疗的AIP病人,开始激素治疗2个月后,复测IgG4较治疗前显著降低。部分轻症的AIP病人,经对症治疗后,可自行缓解。     

Autoimmune pancreatitis with multifocal lesions

Two cases of a focal type of autoimmune pancreatitis (AIP) with distinct double mass lesions within the pancreas are described. In both patients, computed tomography (CT) showed localized pancreatic masses with delayed enhancement, and magnetic resonance cholangiopancreatography (MRCP) revealed localized stenoses of the main pancreatic duct (MPD) with mild upstream dilatation. Fluorodeoxyglucose positron emission tomography (FDG-PET) examination, performed in one patient, showed intense uptake concordant with tumors. Both patients received pancreatic resection with a presumptive diagnosis of pancreatic carcinoma. Histologic evaluation of the tumors showed marked lymphoplasmacytic infiltration and fibrosis around the large and medium pancreatic ducts, without any evidence of malignancy. Serum IgG4 concentration, measured postoperatively, was elevated in both patients. The characteristic morphological features of AIP are diffuse swelling of the pancreatic parenchyma and diffuse narrowing of the MPD. Recently, a focal type of AIP, which mimics pancreatic carcinoma, has been recognized. Considering the favorable response of AIP to steroid therapy, it is clinically important to differentiate the focal type of AIP from pancreatic carcinoma and to know that AIP sometimes exhibits multiple lesions within the pancreas.     

自身免疫性胰腺炎的诊治及外科手术价值研究

目的 总结自身免疫性胰腺炎（AIP）的诊治经验，探讨外科手术在其治疗中的价值。方法 回顾性分析2013年1月至2017年6月福建医科大学附属协和医院收治的17例AIP病人的临床资料。观察临床表现、血液检查结果、影像学表现、诊断及治疗、随访情况。结果 （1）临床表现：17例病人中，7例有梗阻性黄疸，8例上腹痛，1例反复腹泻，1例为因体检发现胰腺肿物。共有11例病人存在胰腺外器官受累。（2）血液检查：13例病人血清免疫球蛋白G4（IgG4）升高，2例正常，2例未查。4例病人CA19-9升高，13例正常。3例病人血清淀粉酶轻度升高，14例正常。（3）影像学检查：所有17例病人均行胰腺CT平扫+增强检查，12例CT表现为弥漫型，5例CT表现为局灶型。（4）诊断及治疗：17例病人均确诊为1型AIP。17例病人中有3例因影像学疑似胰腺癌行手术治疗，术后病理学检查证实为AIP，包括胰十二指肠切除术2例和胰体尾+脾切除术1例。14例AIP病人接受初始口服激素治疗，11例缓解，1例因CA19-9持续升高行胰体尾+脾切除术，1例因胰头假性囊肿逐渐增大伴梗阻性黄疸行胰十二指肠切除术，1例因胰体假性囊肿伴腹痛行胰体囊肿空肠内引流术。（5）随访情况：17例病人均获得随访，平均随访时间为29（12～66）个月。3例初始接受手术的病人术后疾病缓解，复查未见复发。14例接受激素初始治疗的病人，11例有效，疾病缓解；另3例接受手术后继续口服激素治疗3个月，未见复发。结论 AIP的诊断须综合临床表现、血清学、影像学和病理学等检查结果，应用激素是治疗AIP最主要的方法，但外科手术仍占有重要地位，尤其适用于难以与胰腺癌鉴别的局灶型AIP和激素治疗效果欠佳的AIP合并假性囊肿。     

Autoimmune pancreatitis diagnosed after pancreatoduodenectomy and successfully treated with low-dose steroid

A 69-year-old woman presented with obstructive jaundice and a 30-mm hypoechoic mass in the pancreatic head on ultrasonography. Magnetic resonance imaging (MRI) revealed enlargement of the pancreatic head with dilatation of the upstream main pancreatic duct and no dilatation of the proximal biliary tree. Endoscopic retrograde pancreatography showed a localized irregular narrowing of the main pancreatic duct in the head of the pancreas. Pylorus-preserving pancreatoduodenectomy (PPPD) was performed under the diagnosis of pancreatic head cancer. Histopathological examination showed fibrosis with lymphoplasmacytic infiltration, suggesting the diagnosis of autoimmune pancreatitis (AIP). Serum IgG concentration was within normal limits immediately after the operation but was elevated 4 months later, when MRI showed enlargement of the remnant pancreas, with a peripheral rim of low intensity. Oral administration of prednisolone was initiated, at a dose of 5 mg/day. The serum IgG concentration declined and MRI showed improvement of the pancreatic enlargement and the disappearance of the peripheral rim. AIP has not relapsed for 1 year so far, with the patient being kept on 5 mg/day prednisolone. This communication reports a patient with AIP showing an interesting clinical course.     

自身免疫性胰腺炎诊治进展

自身免疫性胰腺炎（AIP）是近年来逐渐被人们认知的一种少见病，属于血清免疫球蛋白G4（IgG4）相关性疾病的一种，病理学表现以胰腺炎症和纤维化为主。自身免疫性胰腺炎的病人在影像学上显示出胰腺“腊肠样肿大”或局部肿块形成，并伴随大量IgG4阳性浆细胞浸润和席纹状纤维化，此类病人对类固醇治疗反应良好。该疾病可通过检测血清IgG4，影像学改变和组织病理学特征进行诊断与鉴别。目前其一线治疗药物是皮质类固醇激素，对于激素不耐受的高风险病人可给予利妥昔单抗。自身免疫性胰腺炎复发率很高，IgG4对于激素治疗疗效评判尚未形成共识，IgG4在疗效评价上价值有限，建议参考临床症状及影像学表现评估治疗效果。     

Peripancreatic vascular involvement in patients with type 1 autoimmune pancreatitis

BackgroundType 1 autoimmune pancreatitis (AIP) is the pancreatic manifestation of IgG4-related disease. However, this benign disease can result in the peripancreatic vascular involvement (PVI) on occasion, which increases the difficulty of diagnosis and treatment of this clinical entity as well as for differentiating it from pancreatic malignancies.MethodsWe retrospectively reviewed the information on demographics, clinical presentation, laboratory, imaging and endoscopic findings of 101 hospitalized patients with type 1 AIP treated in our department. All the patients were divided into non-PVI and PVI groups according to the first hospitalized medical data. Univariate and multivariate analyses were performed to analyse the potential predictive parameter(s) of PVI in AIP patients.ResultsAmong the 101 type 1 AIP patients, 52 (51.5%) exhibited PVI, with a male/female ratio 5.5:1. Their average age was 58.37±8.68 years old. Univariate analysis revealed that the location of pancreatitis lesions, including the pancreatic tail (P=0.010), the presence of splenomegaly (P=0.001) and the white blood cell (WBC) number in peripheral blood (P=0.020), were significantly associated with PVI. The location of pancreatitis lesions, including the pancreatic tail (P=0.023), and the presence of splenomegaly (P=0.010) were found to be independent predictors of the development of PVI by a multivariable regression analysis. A total of 18 out of 25 patients in PVI group who underwent corticosteroid treatment and no less than 6 months radiological follow-up showed improvement in vascular lesions, and no case exhibited exacerbation of PVI lesions during follow-up. Of 36 patients in non-PVI group who were followed up for no less than 6 months, only one case exhibited PVI.ConclusionsThis retrospective study demonstrated that type 1 AIP was associated with a high proportion of PVI. Pancreatic tail involvement and splenomegaly may predict the PVI in type 1 AIP. PVI lesions are reversible in a subset of patients.     

自身免疫性胰腺炎22例临床诊治分析

目的 探索自身免疫性胰腺炎（AIP）的临床特点及诊疗方法。方法 回顾性分析2017年9月至2020年7月在复旦大学附属中山医院胰腺外科诊治的22例AIP病人临床资料。通过记录分析AIP病人初诊及治疗阶段的临床表现,血清IgG4变化情况等辅助检查结果,激素治疗等情况,探索其诊治策略。结果 病人最初就诊时血清IgG4中位数为5.56（0.34～30.30）g/L,其中单纯胰腺受累者2.52（0.34～5.73）g/L,合并其他器官受累者7.59（0.66～30.30）g/L,合并胰腺外器官受累的AIP病人IgG4水平高于单纯胰腺受累的AIP病人（Z= 5.693,P=0.045）;22例病人中有9例接受激素治疗,治疗期间IgG4水平 3.7 （0.99,18.3）g/L,激素治疗2个月后IgG4水平中位数1.63（0.76,8.31）g/L,较未行激素治疗时明显下降（Z=-2.093,P=0.038）。8例病人（激素治疗5例,未激素治疗3例）复发时,IgG4较前均有不同程度升高（8/8,100%）,中位升高数值4.14（0.61,14.81）g/L;4例停药病人中,2例病人IgG4水平未恢复到正常（2/4,50%）。另有13例病人未接受激素治疗,治疗随访时10例（10/13,76.9%）病人处于临床缓解期。结论 在AIP病人中,血清IgG4在多器官受累时升高更为显著。使用激素治疗的AIP病人,开始激素治疗2个月后,复测IgG4较治疗前显著降低。部分轻症的AIP病人,经对症治疗后,可自行缓解。     

自身免疫性胰腺炎临床研究进展

近年来,自身免疫性胰腺炎(AIP)研究逐渐进展.AIP是由自身免疫机制介导的,以淋巴细胞、浆细胞浸润伴有胰腺纤维化及功能障碍为特征的特殊的慢性胰腺炎,可累及胆管、涎腺、肾等胰外器官.常见的临床表现包括梗阻性黄疸、腹痛、体重减轻等,类似于胰腺癌.本病采用类固醇类药物治疗效果显著.目前,各国的AIP诊断标准尚未达成一致.对其病理学分型、影像学表现、血清学标志、活检技术均有各种新进展,而AIP与胰腺癌的鉴别诊断则是研究热点.     

Histamine regulation of pancreatitis and pancreatic cancer: a review of recent findings

The pancreas is a dynamic organ that performs a multitude of functions within the body. Diseases that target the pancreas, like pancreatitis and pancreatic cancer, are devastating and often fatal to the suffering patient. Histamine and histamine receptors (H1-H4HRs) have been found to play a critical role in biliary diseases. Accordingly, the biliary tract and the pancreas share similarities with regards to morphological, phenotypical and functional features and disease progression, studies related the role of H1-H4HRs in pancreatic diseases are important. In this review, we have highlighted the role that histamine, histidine decarboxylase (HDC), histamine receptors and mast cells (the main source of histamine in the body) play during both pancreatitis and pancreatic cancer. The objective of the review is to demonstrate that histamine and histamine signaling may be a potential therapeutic avenue towards treatment strategies for pancreatic diseases.Key Words: Histamine, pancreas, pancreatitis, pancreatic cancer     

Autoimmune pancreatitis: a systemic immune complex mediated disease

Autoimmune pancreatitis (AIP) is a mass forming inflammatory pancreatobiliary-centric disease. Recent reports of multiorgan inflammatory mass forming lesions with increased numbers of IgG4 positive plasma cells suggest that AIP may have a systemic component. In this study, we explore the systemic nature of AIP, investigate the relevance of subtyping AIP, perform a systematic study of tissue IgG4 immunoperoxidase, and ultrastructurally evaluate the presence of immune complexes. Our study group consisted of 36 patients with AIP, 21 of whom underwent a Whipple procedure. On the basis of the pattern of inflammation, pancreatic involvement was subtyped as ductocentric (AIP-D) or lobulocentric (AIP-L). Extrapancreatic lesions included bile duct (n=3), salivary glands (n=3), lung (n=2), gallbladder (n=11), and kidney (n=4). Clinical and radiologic data was recorded. Immunohistochemistry for IgG4 was performed on both pancreatic and extrapancreatic tissues and the numbers of IgG4 positive plasma cells were semiquantitatively scored. A control cohort composed of pancreatic adenocarcinoma (n=19) and chronic pancreatitis-not otherwise specified (NOS) (n=14) was also evaluated. Eleven pancreatic specimens, including 2 cases of chronic pancreatitis-NOS and 4 kidneys were evaluated ultrastructurally. The pancreas, bile duct, gall bladder, salivary gland, kidney, and lung lesions were characterized by dense lymphoplasmacytic infiltrates with reactive fibroblasts and venulitis. IgG4 positive plasma cells were identified in all pancreatic and extrapancreatic lesions. The AIP cases showed significantly more pancreatic IgG4 positive plasma cells than chronic pancreatitis-NOS or adenocarcinoma (P=0.001). However, IgG4 positive cells were identified in 57.1% of chronic pancreatitis-NOS and 47.4% of ductal adenocarcinoma. Fifteen of 21 resected cases were classified as AIP-D, and 6 as AIP-L, the latter notably showing significantly more IgG4 positive plasma cells than the former (P=0.02). Additionally, clinical and radiologic differences emerged between the 2 groups. Ultrastructurally, electron dense deposits of immune complexes were identified in the basement membranes of 7 of the 9 AIP cases and in 3 of the 4 renal biopsies evaluated. AIP represents the pancreatic manifestation of a systemic autoimmune disease. Clinical and immunologic findings justify the recognition of pancreatic lobulocentric and ductocentric subtypes. Documentation of increased numbers of tissue IgG4 positive plasma cells, although not an entirely specific marker for AIP, may provide ancillary evidence for the diagnosis of a IgG4-related systemic disease.     

Pancreatitis after biliary tract surgery

Pancreatitis associated with biliary tract operations continues to be an important clinical problem. The results of biliary tract operations performed on 1256 patients were carefully scrutinized for the presence of postoperative hyperamylasemia and pancreatitis persisting after 48 hours. Patients were evaluated in the context of the presence or absence of preoperative pancreatic dysfunction. Similarly, various operative risk factors were evaluated, including cholangiography, choledocholithiasis, common duct exploration, choledochoscopy, choledochoduodenostomy, and sphincteroplasty. Operative cholangiography did not induce postoperative pancreatitis. The incidence of postoperative pancreatitis following cholecystectomy was 0.6%, which was significantly greater than the incidence following common duct exploration (8.4%). Pancreatitis following biliary tract surgery seemed to be not directly related to the performance of choledochoscopy, sphincteroplasty, or choledochoduodenostomy, as it developed with similar frequency in patients undergoing common duct exploration alone. The timing of operative therapy in patients with biliary tract pancreatitis did not significantly alter the frequency with which pancreatitis persisted in the postoperative period. In 970 patients undergoing cholecystectomy, one patient who had preoperative pancreatitis died of postoperative pancreatitis. Of 286 patients undergoing common duct exploration, seven patients died with pancreatitis. In three of these patients there was no active preoperative pancreatitis, and in one of these patients pancreatitis was the cause of death. Four patients with preoperative pancreatitis eventually died of pancreatitis in the postoperative period. Pancreatitis is an important complication of biliary tract disease and operations, and all efforts should be extended to suppress its occurrence and development.     

Subclassification of autoimmune pancreatitis: a histologic classification with clinical significance

Autoimmune pancreatitis (AIP) is a chronic inflammatory disease of the pancreas. Examination of pancreatic resection specimens from patients with AIP has shown that there are 2 subclasses of this disease. However, there is no widely accepted pathologic classification scheme and the clinical significance of such a classification remains to be established. In this study, we revisited the subclassification of AIP and examine whether this provides clinically and prognostically meaningful information. We evaluated 29 pancreatic resection specimens from patients with AIP. Demographic, clinical, and imaging data were recorded, as was evidence of extrapancreatic manifestations. In addition to a detailed and semiquantitative histologic evaluation, immunohistochemistry for IgG4 was performed on pancreatic and extrapancreatic tissues. We also evaluated 48 consecutive cases of chronic pancreatitis, not otherwise specified. The resected specimens could readily be subclassified into 2 subtypes: type 1 (n=11) and type 2 (n=18). In comparison with patients with type 2 disease, patients with type 1 disease were significantly more likely to be males (P=0.09), older (P=0.02), and present with jaundice (P=0.01), and less likely to be associated with abdominal pain (P=0.04). On imaging, the pancreatic tail cut-off sign was exclusively seen in patients with type 2 disease (4 of 10 cases). Hypercellular inflamed interlobular stroma was unique to type 1 pattern (91%), whereas significant ductal injury in the form of microabscesses and ductal ulceration was almost exclusively seen in type 2 pattern (78%). Eight of 10 patients with a type 1 pattern had evidence of a systemic disease. Three patients with type 2 disease had recurrent episodes of pancreatitis after their pancreatic resection. In comparison with the cohort of chronic pancreatitis, not otherwise specified, type 2 AIP cases were less likely to be associated with a history of alcohol abuse, and showed significantly more foci of periductal inflammation and neutrophilic microabscesses. Our review of pancreatic resection specimens shows 2 histologically distinct forms of AIP. Our data support the concept that type 1 AIP is a systemic disease and is the pancreatic manifestation of IgG4-related systemic disease. Type 2 disease is confined to the pancreas. The intensity of the periductal inflammatory infiltrate and the presence of ductal neutrophilic abscesses are features that assist in distinguishing type 2 AIP from chronic pancreatitis, not otherwise specified. Although imperfect, clinical and imaging features may help distinguish the 2 subtypes of AIP. On the basis of these significant differences between the 2 types of AIP, we advocate the position that all subsequent studies attempt to substratify their patients into these 2 groups.     

Les atteintes uro-néphrologiques au cours de la maladie associée aux IgG4

Hyper-IgG4 syndrome, or IgG4-related disease, is an emerging disorder, involving one or more organ(s), and characterized by “storiform” fibrosis and inflammatory lesions with a predominance of IgG4+ plasma cells and increased IgG4 serum levels. Since the first report of auto-immune pancreatitis, numerous organ lesions have been reported and have been found to occur in a same patient including: sialadenitis, dacryoadenitis, lymphadenopathy, liver and biliary tract involvement, and renal and retroperitoneal lesions. Renal involvement was first described in 2004 and usually presents as functional and/or morphological abnormalities. In most cases, renal pathological analysis reveals tubulointerstitial nephritis that is rarely associated with glomerular lesions. Retroperitoneal fibrosis is also a typical feature that may be associated with periaortitis or inflammatory abdominal aortic aneurysm. First line treatment is based on corticosteroid therapy. Short-term outcome is usually favorable. However, patients should be carefully monitored for relapses and long-term complications. Although the multiple organ lesions share common clinical, biological, radiological and pathological features, no consensus diagnostic criteria have yet been validated for IgG4-related disease. Ruling out differential diagnoses is thus mandatory. Our literature review provides nephrologists, urologists and pathologists with key elements that will help in the early diagnosis and proper management of this new and emerging disorder.     

IgG4-related sclerosing lymphoplasmacytic pancreatitis and cholangitis mimicking carcinoma of pancreas and Klatskin tumour

Background: Autoimmune sclerosing pancreatitis is a well‐known disease entity for years, particularly recognizing the difficulty in distinguishing it from malignancy. Immunohistochemical study showed that immunoglobulin IgG4 staining was positive in plasma cells of some autoimmune pancreatitis or cholangitis. The term ‘autoimmune sclerosing pancreatocholangitis’ was used as it was believed that they belonged to a range of disease involving both pancreas and biliary tree. It may also be part of a systemic fibro‐inflammatory disease. Patients and Methods: All the patients suffering from immunoglobulin G4 (IgG4)‐related pancreatitis and cholangitis from May 2003 to September 2006 in Queen Elizabeth Hospital, Hong Kong were retrospectively studied. Results: A total of five patients with clinical diagnosis of IgG4‐related autoimmune pancreatitis or cholangitis were analysed. All presented with jaundice or abdominal pain, mimicking carcinoma. Two patients had major resection, two patients were diagnosed by intraoperative biopsy and one was based on serum IgG4 level. Conclusion: With the growing awareness of this relatively recently characterized clinical entity and its similar presentation to pancreatic carcinoma or bile duct cholangiocarcinoma, it is important for autoimmune sclerosing pancreatocholangitis to be included in the differential diagnosis of pancreaticobiliary disease. The management strategy has shown to be modified – from major resection to intraoperative biopsy and to the assay of serum IgG4 level without the necessity of histology confirmation.