Autoimmune pancreatitis associated with a large pancreatic pseudocyst that disappeared after corticosteroid therapy: a case report and literature review

A 51-year-old woman was admitted to our department because of upper abdominal pain. The serum IgG4 concentration was elevated, and abdominal computed tomography revealed diffuse enlargement of the pancreas associated with a large cyst, measuring 8 cm in diameter. Endoscopic retrograde cholangiopancreatography revealed narrowing of the main pancreatic duct (from the body to the tail), narrowing of the intrapancreatic bile duct, and dilatation of the bile ducts. The patient was given a diagnosis of autoimmune pancreatitis (AIP) associated with a pancreatic pseudocyst and intrapancreatic bile duct stenosis. Oral steroid therapy resulted in reduced pancreatic swelling, complete disappearance of the pancreatic cyst, and an improvement in biliary stenosis. AIP is rarely associated with pancreatic cyst, and only 13 cases, including ours, have been reported to date. In our patient, intense inflammation apparently led to cyst formation in association with AIP, which responded remarkably to corticosteroid therapy. Correct diagnosis of AIP associated with a pancreatic pseudocyst might save patients from undergoing unnecessary endoscopic and surgical procedures.     

A case of focal autoimmune pancreatitis (AIP) mimicking an intraductal papillary mucinous neoplasm (IPMN)

The present case involved a 76-year-old man with a cystic mass in the head of his pancreas. The cystic lesion, which measured 17.7 × 9.8 mm, was first detected by ultrasonography (US) at the age of 72 years. Follow-up endoscopic ultrasonography (EUS) performed at 4 years after the lesion had first been detected revealed a mural nodule measuring 14.0 × 8.4 mm in the cyst. Endoscopic retrograde pancreatography (ERP) imaging revealed that the main pancreatic duct was in communication with the cyst and that there was no irregular narrowing of the main pancreatic duct. On the basis of these results, the patient was diagnosed with an intraductal papillary mucinous neoplasm (IPMN), and stomach-preserving pancreaticoduodenectomy was performed. A histopathological examination revealed that the interior of the cystic part of the lesion was lined by a pancreatic ductal epithelium. A pathological examination of the nodular lesion detected storiform fibrosis, severe lymphoplasmacytic infiltration, and hyperplasia in the pancreatic duct epithelium together with a small amount of mucus. On immunohistological staining, the infiltrating lymphoplasmacytes were found to be positive for IgG4. Accordingly, the patient was diagnosed with focal autoimmune pancreatitis (AIP). In conclusion, we reported a case of focal AIP mimicking IPMN. This case showed neither enlargement of the pancreas nor irregular narrowing of the main pancreatic duct.     

Intraductal papillary mucinous neoplasm of the pancreas and IgG4-related disease: A coincidental association

Background/aimsCoexistence of autoimmune pancreatitis (AIP) and pancreatic cancer, elevation of serum IgG4 levels in pancreatic cancer patients, and infiltration of IgG4-positive plasma cells in peritumorous pancreatitis have been described in a few reports. This study examined the relationship between intraductal papillary mucinous neoplasm (IPMN) of the pancreas and peritumorous IgG4-positive lymphoplasmacytic infiltrates.MethodsSerum IgG4 levels were measured in 54 patients with IPMN (median 70 years, 26 males and 28 females; 13 main duct type and 41 branch duct type). Histological findings focusing on dense lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis were reviewed, and immunostaining with IgG4 and IgG was performed in 23 surgically resected IPMN cases (18 main duct type and 5 branch duct type). The presence of IgG4-positive plasma cells >10/hpf and an IgG4-positive/IgG-positive plasma cell ratio >40% were considered significant.ResultsSerum IgG4 levels were elevated in 2 (4%) IPMN patients. Significant infiltration of IgG4-positive plasma cells was detected in 4 IPMN cases (17%). The IgG4-positive/IgG-positive plasma cell ratio was >40% in all 4 cases. In one case with a markedly elevated serum IgG4 level (624 mg/dL), typical lymphoplasmacytic sclerosing pancreatitis (AIP type 1) lesions surrounded the whole IPMN. In the 3 other cases, infiltration of IgG4-positive plasma cells with fibrosis was focally detected mainly in the periductal area around the IPMN.ConclusionsIn a few patients with IPMNs, IgG4-positive plasma cell infiltration can occur in the peritumorous area. The association of an IPMN with AIP type 1-like changes seems to be exceptional and coincidental.     

Autoimmune pancreatitis mimicking an intra-ductal papillary mucinous neoplasm of the pancreas: an original case

In recent years, autoimmune pancreatitis (AIP) has been increasingly recognized. It can be associated with diabetes mellitus and other systemic autoimmune diseases, or with bile ducts lesions, which are also responsive to steroid therapy as pancreatic lesions. We report the case of a 34-year-old man with a history of a first acute pancreatitis, attributed to an intraductal papillary-mucinous neoplasm of the pancreas (IPMN) with segmental involvement of the main pancreatic duct. A spleno-pancreatectomy was performed, and pathological examination of the specimen diagnosed autoimmune pancreatitis. A treatment with corticosteroids was carried out. To our knowledge, this is the first reported case of AIP mimicking IPMN of the main pancreatic duct.     

IgG4-unrelated type 1 autoimmune pancreatitis

A 50-year-old male was referred to our hospital for the evaluation of hyperproteinemia.Fluorodeoxyglucose positron emission tomography revealed high fluorodeoxyglucose uptake in the pancreas,bilateral lacrimal glands,submandibular glands,parotid glands,bilateral pulmonary hilar lymph nodes,and kidneys.Laboratory data showed an elevation of hepatobiliary enzymes,renal dysfunction,and remarkably high immunoglobulin(Ig) G levels,without elevated serum IgG4.Abdominal computed tomography revealed swelling of the pancreatic head and bilateral kidneys.Endoscopic retrograde cholangiopancreatography showed an irregular narrowing of the main pancreatic duct in the pancreatic head and stricture of the lower common bile duct.Histological examination by endoscopic ultrasonography-guided fine-needle aspiration revealed findings of lymphoplasmacytic sclerosing pancreatitis without IgG4-positive plasma cells.Abnormal laboratory values and the swelling of several organs were improved by the treatment with steroids.The patient was diagnosed as having type 1 autoimmune pancreatitis(AIP) based on the International Consensus Diagnostic Criteria.Therefore,we encountered a case of compatible type 1 AIP without elevated levels of serum IgG4 or IgG4-positive plasma cells.This case suggests that AIP phenotypes are not always associated with IgG4.     

Autoimmune pancreatitis associated with hemorrhagic pseudocysts: a case report and literature review

Autoimmune pancreatitis (AIP) is a new category of pancreatic diseases. AIP associated with pseudocysts is rare; only 8 cases have been reported in the literature. A 63-year-old man was admitted to our department because of upper left abdominal pain and back pain. Various imaging studies demonstrated swelling of the tail of the pancreas with hemorrhagic pseudocysts. The patient underwent a surgical operation. A pancreatogram of the specimen revealed total occlusion of the main pancreatic duct in the tail of the pancreas. Histopathological examination revealed that it was AIP with hemorrhagic pseudocysts.     

自身免疫性胰腺炎16例的临床分析

目的 总结并探讨自身免疫性胰腺炎(AIP)的临床特征及其诊断与治疗.方法 回顾性分析北京协和医院2003年3月至2008年1月确诊的16例AIP患者资料.结果 AIP患者以男性居多,男∶女为15∶1,平均年龄61岁(47～79岁).81.2%的患者以黄疸为主要临床表现.68.8%的患者有高γ球蛋白血症,66.7%血IgG增高,56.2%红细胞沉降率增快,50.0%类风湿因子阳性,43.7%嗜酸粒细胞升高,26.7%抗核抗体阳性,31.2%血清脂肪酶升高,18.7%血淀粉酶一过性升高,25.0%CA19-9升高.腹部CT和(或)内镜超声(EUS)示93.7%患者的胰腺弥漫性肿大,100%胰管狭窄、87.5%合并胆总管胰腺段狭窄,50.0%胆管壁增厚.EUS下穿刺活检6例,1例无结果,5例均未见肿瘤细胞;3例见淋巴细胞浸润;2例有胰腺纤维化.75.0%合并糖尿病或糖耐量异常,43.7%见腹腔淋巴结肿大,42.9%有脾静脉或下腔静脉受累,18.7%合并泪腺肿大,12.5%合并颌下腺肿大.11例应用泼尼松治疗(其中7例同时胆总管支架置入),10例效果良好,1例因不耐受而停用;2例单纯行胆总管支架置入术,黄疸解除;3例仅对症治疗.激素对糖尿病患者血糖水平影响不一,泪腺与颌下腺肿大者在激素治疗后迅速消肿.结论 AIP好发于中老年男性,多以无痛性、梗阻性黄疸首诊.可有血清IgG和球蛋白升高,抗核抗体和类风湿因子阳性.影像学见胰腺弥漫或局限性肿大、胰管狭窄、胆总管胰腺段狭窄.激素治疗有效,支架植入可缓解症状.     

Acute pancreatitis-onset carcinoma in situ of the pancreas with focal fat replacement diagnosed using serial pancreatic-juice aspiration cytologic examination (SPACE)

A 59-year-old woman was admitted for acute pancreatitis. Abdominal computed tomography and magnetic resonance imaging revealed a swollen pancreatic parenchyma with dilatation of the main pancreatic duct (MPD) of the pancreas tail, which was separated from the normal pancreas body side by a locally atrophic part of the pancreas. Magnetic resonance cholangiopancreatography showed MPD stricture in the pancreas tail with dilatation of the upstream MPD. Endoscopic ultrasonography revealed that the MPD stricture of the pancreas tail was surrounded by a blurred and hypoechoic area. Endoscopic retrograde cholangiopancreatography was performed for serial pancreatic-juice aspiration cytologic examination (SPACE). The result indicated adenocarcinoma. Distal pancreatectomy was performed, and the histopathological examination showed high-grade PanIN (carcinoma in situ of the pancreatic duct) of the pancreas tail with atrophy and fibrosis of the pancreatic parenchyma, and local fat replacement adjacent to the lesion. The final histopathological diagnosis was carcinoma in situ of the pancreatic duct of the pancreas tail. Acute pancreatitis and local fatty change of the pancreatic parenchyma with MPD stricture are important clinical manifestations of pancreatic carcinoma in situ (PCIS) and performing SPACE in cases of MPD stricture without a recognizable mass is preferable for a diagnosis of PCIS.     

A case of pancreatic carcinoma with suspected autoimmune pancreatitis

We present a case of pancreatic carcinoma with strongly suspected coexisting autoimmune pancreatitis (AIP). The patient presented with a chief complaint of icterus and weight loss, and was referred to our institution after a pancreatic lesion was found. Blood test showed elevation of serum bilirubin, hepato-biliary enzyme, glucose and tumor markers, and also high levels of serum IgG4 (344 mg/dl, normal 4.8–105 mg/dl) and anti-DNA antibody (14 IU/ml, normal <6.0 IU/ml). Ultrasonography demonstrated an enlarged pancreas with smooth borders and low internal echo density. Enhanced computed tomography (CT) showed a sausage-shaped pancreas without definitive metastasis to the surrounding lymph nodes and liver. Imaging of the pancreatic duct, including endoscopic retrograde pancreatography (ERP) and magnetic resonance cholangiopancreatography (MRCP), showed stenosis of the main pancreatic duct at the pancreatic head as well as a long segment of narrowing at the body and no dilatation at the tail. Tissues from these stenotic sites and open biopsy from pancreatic body showed infiltrating adenocarcinoma and dense fibrosis. To date, only a small number of reports have described pancreatic carcinoma accompanied with AIP. It is important to confirm diagnosis with histology in cases of suspicious autoimmune pancreatitis, even when the clinical images are compatible with AIP.     

Isolated intrapancreatic Ig G4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis(Ig G4-SC) is frequently associated with type 1 autoimmune pancreatitis(AIP). Association with AIP can be utilized in the diagnosis of Ig G4-SC. However, some cases of Ig G4-SC are isolated from AIP, which complicates the diagnosis. Most of the reported cases of isolated Ig G4-SC displayed hilar biliary strictures, whereas isolated Ig G4-SC with intrapancreatic biliary stricture is very rare. Recently, we have encountered 5 isolated intrapancreatic Ig G4-SC cases that were not associated with AIP, three of which were pathologically investigated after surgical operation. They all were males with a mean age of 74.2 years. The pancreas was not enlarged in any of these cases. No irregular narrowing of the main pancreatic duct was found. Bile duct wall thickening in lesions without luminal stenosis was detected by abdominal computed tomography in all five cases, by endoscopic ultrasonography in two out of four cases and by intraductal ultrasonography in all three cases. In three cases, serum Ig G4 levels were within the normal limits. The mean serum Ig G4 level measured before surgery was 202.1 mg/d L(4 cases). Isolated intrapancreatic Ig G4-SC is difficult to diagnose, especially if the Ig G4 level remains normal. Thus, this type of Ig G4-SC should be suspected in addition to cholangiocarcinoma and pancreatic cancer if stenosis of intrapancreatic bile duct is present.     

A case of concurrent pancreatic intraepithelial neoplasia and type 1 autoimmune pancreatitis with marked pancreatic duct dilatation

The case patient was a previously healthy 82-year-old male. Abdominal ultrasound during a medical check-up revealed a dilatation of the main pancreatic duct, and the patient was referred to our hospital for closer examination. Contrast-enhanced computed tomography (CT) revealed a low-density mass of 20 mm in the pancreatic head–body transitional area. Magnetic resonance cholangiopancreatography (MRCP) revealed marked dilatation of the main pancreatic duct and branches in the body–tail. On endoscopic ultrasonography (EUS), a hypoechoic mass with irregular shape was detected, which was consistent with the area of pancreatic duct stenosis. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and pancreatic juice cytology were performed; however, there were no malignant findings. Serum IgG4 levels had increased to 299 mg/dL. Cancer of the pancreatic head was suspected and a pancreaticoduodenectomy was thus performed. Macroscopic findings included a white mass with indistinct border in the constricted part of the pancreatic duct and mottled fatty replacement of the pancreatic head. Pathologically, a large amount of IgG4-positive plasma cells was found in the white mass, with storiform fibrosis and obstructive phlebitis, which led to the diagnosis of type 1 autoimmune pancreatitis (AIP). Furthermore, scattered low–high grade pancreatic intraepithelial neoplasia lesions were observed throughout the pancreatic head, separately from the AIP lesion. This is an interesting case that suggests an association between AIP and pancreatic cancer. We report the case with a review of relevant literature.     

A case of sclerosing cholangitis without pancreatic involvement thought to be associated with autoimmunity

Sclerosing cholangitis (SC) is one of the lesions frequently seen in IgG4-related systemic diseases, causing biliary stricture and mimicking bile duct carcinoma and primary sclerosing cholangitis (PSC). Although it often accompanies autoimmune pancreatitis (AIP), autoimmune-related SC without a pancreatic lesion is very rare. A 79-year-old woman was referred to our institution with suspected diagnosis of bile duct carcinoma in the previous hospital. The patient was not icteric and fever free, but with an elevated level of serum biliary enzyme, which lead us to detect this disease. Clinical images including computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP) and intraductal ultrasonography (IDUS) demonstrated multiple strictures at the intrahepatic bile duct and enhanced wall thickness at the upper common bile duct, however her pancreas was normal. Repeated endoscopic procedures with multiple biopsies from the biliary strictures demonstrated fibrous ductal tissues with lymph-plasma cell infiltration (>10 IgG4(+) cells/HPF). By positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET), the uptake of FDG was not remarkable in areas other than the biliary lesions. Additional laboratory tests showed elevated levels of serum IgG (2,571 mg/dL), and γ-globulin (29%), and positive autoantibodies, but normal IgG4 (53.2 mg/dL). Together with clinical images, laboratory and histological findings, we diagnosed this patient as sclerosing cholangitis which was thought to be associated with autoimmunity. After one year of follow-up without steroid therapy, idiopathic thrombocytopenic purpura (ITP) developed with an increased level of serological markers. We encountered a rare case of sclerosing cholangitis expected to be associated with autoimmunity, which showed biliary strictures mimicking bile duct carcinoma and needed careful diagnosis. Unlike the typical AIP, the current case demonstrated distinct serological findings and no other organ involvement. Further study is needed to clarify the characteristics of sclerosing cholangitis associated with autoimmunity with a large number of cases.     

自身免疫性胰腺炎的影像特征及其诊断价值

目的 探讨自身免疫性胰腺炎(AIP)的影像特征及其在AIP诊断中的价值.方法 回顾性分析13例AIP患者的影像和临床资料.结果 11例AIP表现为胰腺弥漫性肿大,2例胰头局限性肿大.CT平扫病变密度均均匀.4例在MR T1WI上信号降低、T2WI上信号轻度升高,增强后动脉期病变轻度强化,门脉期及延迟期进一步强化.9例胰腺周围有包膜样结构.横轴位图像上肝内外胆管扩张、胆总管胰腺段狭窄或闭塞10例,胰管未显影11例.6例行MRCP者有4例显示胆总管胰腺段较大范围狭窄或闭塞,胰管节段性狭窄.7例ERCP显示胰管弥漫性、不规则狭窄.胰周静脉受累8例,肾脏多发低密度灶6例,腹膜后纤维化2例,肝门部胆管狭窄1例,肺间质病变1例,强直性脊柱炎1例.结论 AIP的影像学征象具有一定特征性,影像检查在AIP诊断中起重要作用.识别胰腺外脏器受累对正确诊断AIP有帮助.     

Role of endoscopy in the diagnosis of autoimmune pancreatitis and immunoglobulin G4‐related sclerosing cholangitis

Autoimmune pancreatitis (AIP) must be differentiated from pancreatic carcinoma, and immunoglobulin (Ig)G4‐related sclerosing cholangitis (SC) from cholangiocarcinoma and primary sclerosing cholangitis (PSC). Pancreatographic findings such as a long narrowing of the main pancreatic duct, lack of upstream dilatation, skipped narrowed lesions, and side branches arising from the narrowed portion suggest AIP rather than pancreatic carcinoma. Cholangiographic findings for PSC, including band‐like stricture, beaded or pruned‐tree appearance, or diverticulum‐like outpouching are rarely observed in IgG4‐SC patients, whereas dilatation after a long stricture of the bile duct is common in IgG4‐SC. Transpapillary biopsy for bile duct stricture is useful to rule out cholangiocarcinoma and to support the diagnosis of IgG4‐SC with IgG4‐immunostaining. IgG4‐immunostaining of biopsy specimens from the major papilla advances a diagnosis of AIP. Contrast‐enhanced endoscopic ultrasonography (EUS) and EUS elastography have the potential to predict the histological nature of the lesions. Intraductal ultrasonographic finding of wall thickening in the non‐stenotic bile duct on cholangiography is useful for distinguishing IgG4‐SC from cholangiocarcinoma. Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is widely used to exclude pancreatic carcinoma. To obtain adequate tissue samples for the histological diagnosis of AIP, EUS‐Tru‐cut biopsy or EUS‐FNA using a 19‐gauge needle is recommended, but EUS‐FNA with a 22‐gauge needle can also provide sufficient histological samples with careful sample processing after collection and rapid motion of the FNA needles within the pancreas. Validation of endoscopic imaging criteria and new techniques or devices to increase the diagnostic yield of endoscopic tissue sampling should be developed.     

Strategy to differentiate autoimmune pancreatitis from pancreas cancer

Autoimmune pancreatitis (AIP) is a newly described entity of pancreatitis in which the pathogenesis appears to involve autoimmune mechanisms. Based on histological and immunohistochemical examinations of various organs of AIP patients, AIP appears to be a pancreatic lesion reflecting a systemic "IgG4-related sclerosing disease". Clinically, AIP patients and patients with pancreatic cancer share many features, such as preponderance of elderly males, frequent initial symptom of painless jaundice, development of new-onset diabetes mellitus, and elevated levels of serum tumor markers. It is of uppermost importance not to misdiagnose AIP as pancreatic cancer. Since there is currently no diagnostic serological marker for AIP, and approach to the pancreas for histological examination is generally difficult, AIP is diagnosed using a combination of clinical, serological, morphological, and histopathological features. Findings suggesting AIP rather than pancreatic cancer include: fluctuating obstructive jaundice; elevated serum IgG4 levels; diffuse enlargement of the pancreas; delayed enhancement of the enlarged pancreas and presence of a capsule-like rim on dynamic computed tomography; low apparent diffusion coefficient values on diffusion-weighted magnetic resonance image; irregular narrowing of the main pancreatic duct on endoscopic retrograde cholangiopancreatography; less upstream dilatation of the main pancreatic duct on magnetic resonance cholangiopancreatography, presence of other organ involvement such as bilateral salivary gland swelling, retroperitoneal fibrosis and hilar or intrahepatic sclerosing cholangitis; negative work-up for malignancy including endoscopic ultrasound-guided fine needle aspiration; and steroid responsiveness. Since AIP responds dramatically to steroid therapy, accurate diagnosis of AIP can avoid unnecessary laparotomy or pancreatic resection.     

Autoimmune pancreatitis with IgG4-positive plasma cell infiltration in salivary glands and biliary tract

A 62-year-old male was referred to our hospital because of liver dysfunction, diffuse pancreatic swelling, and trachelophyma. At admission, the patient was free of pain. Physical examination showed enlarged and palpable bilateral submandibular masses, but no palpable mass or organomegaly in the abdomen. Laboratory findings were as follows: total protein 90 g/L with y-globulin of 37.3% (33 g/L), total bilirubin 4 mg/L, aspartate aminotransferase 39 IU/L, alanine aminotransferase 67 IU/L, y-glutamyl transpeptidase 1 647 IU/L, and amylase 135 IU/L. Autoanti-bodies were negative, and tumor markers were within the normal range. Serum IgG4 level was markedly elevated (18 900 mg/L). Computed tomography (CT) showed diffuse swelling of the pancreas and dilatation of both common and intra-hepatic bile ducts. Endoscopic retrograde pancreatography (ERP) revealed diffuse irregular and narrow main pancreatic duct and stenosis of the lower common bile duct. Biopsy specimens from the pancreas, salivary gland and liver showed marked periductal IgG4-positive plasma cell infiltration with fibrosis. We considered this patient to be autoimmune pancreatitis (AIP) with fibrosderosis of the salivary gland and biliary tract, prescribed prednisolone at an initial dose of 40 mg/d. Three months later, the laboratory data improved almost to normal. Abdominal CT reflected prominent improvement in the pancreatic lesion. Swelling of the salivary gland also improved. At present, the patient is on 10 mg/d of prednisolone without recurrence of the pancreatitis. We present here a case of AIP with fibrosderosis of salivary gland and biliary tract.     

Atypical ductal hyperplasia of the pancreas associated with a stricture of the main pancreatic duct

Atypical ductal hyperplasia of the pancreas is thought to be a precancerous lesion. We report a case of atypical ductal hyperplasia associated with a stricture of the main pancreatic duct. A 70-year-old man was admitted to our hospital because of abdominal pain with an elevated serum pancreatic isoamylase level. Endoscopic retrograde cholangiopancreatography disclosed a stricture of the main pancreatic duct in the body of the pancreas. Cytological evaluation of endoscopic brushings suggested adenocarcinoma. Distal pancreatec-tomy was performed. Microscopic examination of the stenotic pancreatic duct showed a hyperplastic epithelium without atypia. Atypical hyperplasia, however, was found in the distal portion of the main pancreatic duct in close proximity to the stricture. Atypical hyperplasia extended along the main pancreatic duct into the ductal branches of the pancreatic tail. In contrast to the vast majority of patients with atypical hyperplasia, the atypical hyperplasia seen in the present patient had no histological features suggestive of intraductal extension of the invasive carcinoma or intraductal papillary-mucinous tumor, thus representing a sporadic precancerous lesion, and it may have been equivalent to carcinoma in situ. Pancreatic duct stricture and the resultant stasis of the pancreatic juice may have promoted the atypical changes in the ductal cells upstream of the stricture. Received: August 20, 2001 / Accepted: February 8, 2002 Reprint requests to: M. Kogire Editorial on page 311     

自身免疫性胰腺炎误诊误治17例临床分析

目的 总结自身免疫性胰腺炎(AIP)误诊误治的原因.方法 回顾性分析2005年5月至2010年7月间我院收治的17例有误诊误治经历的AIP患者的临床资料.结果 AIP的主要临床症状包括腹部轻度疼痛13例、进行性黄疸12例、发热6例、体重减轻9例.15例伴随一种或一种以上胰腺外脏器的自身免疫性疾病,包括过敏性鼻炎、颌下淋巴结肿大、颌下腺肿大、过敏性哮喘、类风湿性关节炎、干燥综合征、糖尿病、原发性硬化性胆管炎和自身免疫性肝炎.实验室检查方面,血清球蛋白增高11例、IgG增高14例、γ球蛋白增高13例、抗核抗体阳性13例、抗胰岛素IgG抗体阳性2例.影像学检查方面,胰腺弥漫性肿大15例,伴主胰管弥漫性狭窄或节段性狭窄、胰腺段胆总管狭窄、近端胆管扩张、胆囊增大;胰头、钩突局灶性肿大2例.17例中有13例误诊为胰腺癌,其中4例行胰十二指肠切除术,7例行胆肠吻合术,2例被认为肿瘤晚期失去治疗机会;4例被误诊为普通慢性胰腺炎.确诊AIP后,17例患者均接受糖皮质激素治疗,效果显著.随访6～45个月(平均15个月),4例复发,再次子糖皮质激素治疗效果好.随访期间未发现胰腺癌.结论 AIP 临床特点与胰腺癌相似,加之我国现阶段对AIP认识不足、重视不够,是导致误诊和误治的主要原因.

Abstract：

Objective To summarize the reasons of mis-diagnosis and mis-treatment of autoimmune pancreatitis (AIP). Methods Clinical data of 17 patients with AIP,who were admitted to the hospital from May 2005 to July 2010 and experienced mis-diagnosis and mis-treatment, were retrospectively analyzed. Results The main clinical manifestations included epigastric pain (13 cases),progressive obstructive jaundice (12 cases), fever (6 cases) and weight loss (9 cases). Fifteen patients had extrapancreatic organ involvemnet, including allergic rhinitis, swelling of lymphoglandulae submaxillares, swelling of submaxillary gland, allergic asthma, rheumatoid arthritis, Sjogren syndrome, diabetes mellitus, primary sclerosing cholangitis and autoimmune hepatitis. Of these 17 cases, 11 cases presented with high serum globulin, 14 cases with high serum IgG, 13 cases with high serum γ-globulin, 13 cases with positive anti-nuclear antibody and 2 cases with positive anti-insulin IgG antibody. The abdominal imaging demonstrated that 15 patients had diffuse enlargement of the pancreas with diffuse or segmental narrowing of main pancreatic duct, narrowing of the intrapancreatic common bile duct, dilation of the proximal biliary duct and gallbladder enlargement. Focal enlargement of the pancreas was found in 2 cases. Thirteen cases were misdiagnosed as pancreatic carcinoma. Among them, 4 cases underwent pancreaticoduodenectomy and 7 cases underwent choledochojejunostomy. Two cases were misdiagnosed as end stage of cancer that lost therapeutic chance. Another 4 cases were misdiagnosed as chronic pancreatitis. Steroid therapy was administered in all patients with satisfactory response. All patients were followed-up for 15 months (ranged from 6 months to 45 months), and recurrence was found in 4 cases. Satisfactory response was found in patients treated with steroid for the second time. No pancreatic cancer was found in these patients in the follow up period. Conclusion The main causes of mis-diagnosis and mis-treatment of AIP may be contributed by difficulty in differentiating AIP from pancreatic carcinoma based on clinical manifestations and inadequate knowledge of AIP as well as insufficient attention to AIP in China.     

Autoimmune pancreatitis type-1 associated with intraduct papillary mucinous neoplasm: Report of two cases

Chronic pancreatitis lesions usually embrace both intraduct papillary mucinous neoplasm (IPMN) and pancreatic ductal adenocarcinoma (PDAC). Patients at genetically-determined high risk of PDAC often harbor IPMN and/or chronic pancreatitis, suggesting IPMN, chronic pancreatitis and PDAC may share pathogenetic mechanisms. Chronic autoimmune pancreatitis (AIP) may also herald PDAC. Concurrent IPMN and AIP have been reported in few patients. Here we describe two patients with IPMN who developed type-1 AIP fulfilling the Honolulu and Boston diagnostic criteria. AIP diffusively affected the whole pancreas, as well as peripancreatic lymph nodes and the gallbladder. Previous pancreatic resection of focal IPMN did not show features of AIP. One of the patients carried a CFTR class-I mutation. Of notice, serum IgG4 levels gradually decreased to normal values after IPMN excision. Common risk factors to IPMN and AIP may facilitate its coincidental generation.     

A case of mixed adenoneuroendocrine carcinoma of the pancreas mimicking intraductal papillary mucinous carcinoma

A previously healthy 52-year-old man was referred to our hospital for further evaluation of main pancreatic duct dilatation. The preoperative work-up was consistent with intraductal papillary mucinous carcinoma (IPMC) derived from a mixed type intraductal papillary mucinous neoplasm (IPMN), because multilocular cysts with enhancing thickened pancreatic head walls and dilated pancreatic ducts lined with dysplastic mucinous epithelium, with papillary proliferation from the pancreatic body to the tail, were observed; in addition, the pancreatic juice cytology was class V, which is suggestive of adenocarcinoma. Total pancreatectomy was performed because a definite mass was not found before surgical resection and the tumors could have spread to the tail. The pathological diagnosis was mixed adenoneuroendocrine carcinoma of the pancreatic head. IPMN with high- or low-grade dysplasia was not observed anywhere in the pancreatic duct. The pancreatic ductal adenocarcinoma consisted of large caliber malignant glands with intraluminal flat or papillary structures; therefore, we were unable to recognize a definite pancreatic mass before surgical resection, and suspected an IPMC derived from a mixed type IPMN.