自身免疫性胰腺炎的CT和MRI的影像学表现

目的探讨自身免疫性胰腺炎CT和MRI的影像学特点,提高对自身免疫性胰腺炎的认识和影像学诊断水平。方法回顾性分析45例经激素治疗或手术病理证实的自身免疫性胰腺炎患者的CT和MRI影像学资料,观察胰腺及周围组织、胰管和胆管的影像学表现,总结自身免疫性胰腺炎CT和MRI的影像学特点。结果 45例自身免疫性胰腺炎患者中,男性32例,女性13例,其中37例患者表现为胰腺的弥漫性肿大,8例患者表现为胰腺局限性肿大,CT检查中有27例患者的胰腺病灶平扫密度减低;MRI检查中有16例患者胰腺病灶出现信号的改变,表现为T1WI上低信号,T2WI上稍高信号;45例患者胰腺病灶均表现为延迟强化方式改变。10例患者的CT和7例患者的MRI表现为胰管狭窄,2例患者的CT和1例的患者MRI表现为胆总管狭窄。14例患者的CT及MRI表现胰腺周围的"假包膜"征象。结论自身免疫性胰腺炎在CT和MRI上具有一定的影像学特点,结合实验室相关检查有助于该疾病的诊断。     

自身免疫性胰腺炎的CT表现特征(附4例分析)

目的探讨自身免疫性胰腺炎(AIP)的CT表现特征。方法收集4例经临床、实验室检查和类固醇激素治疗有效的AIP患者的CT资料。CT检查包括平扫、双期(动脉期和门静脉期)增强扫描,在CT图像上观察胰腺的形态、大小、质地、强化程度、胰管、胰腺边缘、胰周及腹膜后各间隙等情况并分析AIP的CT表现特征。结果3例AIP表现为胰腺弥漫性肿大,1例为胰头的局限性肿大;病变区域胰腺实质在动脉期强化减弱但出现明显的延时强化;2例在胰腺病变区周围环绕包膜样结构;2例伴胆总管胰头段狭窄,1例ERCP显示胰管不规则狭窄;经类固醇激素治疗后,CT复查显示胰腺情况明显好转。结论AIP的CT表现具有一定的特征性。     

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14例临床分析

目的 探讨自身免疫性胰腺炎(AIP)的特征性表现,以提高对其的认识程度和诊治水平.方法 对2002年2月至2008年4月间收治的14例AIP患者的临床表现以及影像学、实验室、病理学资料和治疗效果进行回顾性分析,其中男性13例,女性1例,年龄35～71岁,平均53岁.临床表现为进行性皮肤巩膜黄染11例,持续性或间歇性上腹胀痛不适3例.结果 CT检查表现为胰腺弥漫性肿大伴胰管弥漫性不规则狭窄11例,胰头局灶性肿大伴胰头处胰管狭窄3例,全部病例均有胆总管胰腺段狭窄.共有12例患者接受免疫球蛋白G(IgG)和自身抗体检测,其中7例IgG浓度升高,6例自身抗体阳性.14例AIP患者中,9例就诊时存在或随访中出现胰腺外其他自身免疫性疾病.病理检查显示3例胰腺导管周围有致密的淋巴细胞和浆细胞浸润伴间质纤维化.因怀疑胰腺恶性肿瘤而行手术治疗7例,给予皮质类固醇激素治疗7例,治疗结果满意.随访中有4例复发.结论 MP应该作为胰腺癌的一种鉴别诊断,避免因误诊而进行不必要的手术治疗.     

CT与MRI检查对自身免疫性胰腺炎的诊断价值

目的 探讨CT与MRI检查对自身免疫性胰腺炎（AIP）的诊断价值。方法 回顾性分析2011年 6月至2013年12月期间眉山市中医医院收治的14例AIP患者的临床和影像学资料。结果 CT和MRI检查示AIP患者的胰腺弥漫性肿大呈腊肠状,T1WI示胰腺实质信号明显减低,扩散加权成像（DWI）示胰腺实质信号明显增高;增强扫描后动脉期胰腺实质强化幅度明显降低,延迟期呈持续性延迟强化伴包膜征,胆总管胰腺段呈鸟嘴样狭窄。结论 AIP的影像学表现具有一定的特征性,结合临床表现及实验室检查可早期诊断,对选择治疗方案具有重要意义。     

Invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma without mucin hypersecretion but with changes in the pancreatic duct on pancreatography

We present a case of invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma without mucin hypersecretion in a 65-year-old man with a 45-year history of alcohol abuse and a 2-year follow-up of chronic pancreatitis. Two years previously, in May 1998, he was admitted for investigation of abdominal pain. Computed tomography (CT) showed diffuse dilation of the main pancreatic duct with atrophy of the pancreatic parenchyma. Endoscopic retrograde pancreatography (ERP) showed a diffusely dilated main pancreatic duct with irregular side branches in the head of the pancreas. Chronic alcoholic pancreatitis was diagnosed on the basis of the pancreatography findings. The patient was readmitted for investigation of progressive weight loss in August 2000. Serum CA19-9 levels were markedly elevated (750 U/ml) and CT showed enlargement of the head and body of the pancreas. ERP showed irregularity of the main pancreatic duct in the head of the pancreas, and the distal main pancreatic duct (which was dilated on initial ERP examination) was interrupted in the body of the pancreas. Suspected pancreatic carcinoma was diagnosed, and pylorus-preserving pancreatoduodenectomy was performed. Frozen section examination of the cut end of the pancreas revealed ductal carcinoma, and total pancreatoduodenectomy with portal vein resection was performed. Histologically, the resected tumor was diagnosed as an invasive carcinoma derived from intraductal papillary adenocarcinoma without mucin hypersecretion. We recommend observing changes in the pancreatic duct on pancreatography to diagnose invasive carcinoma of the pancreas derived from intraductal papillary adenocarcinoma in a resectable state. Received: February 6, 2002 / Accepted: June 10, 2002 Offprint requests to: S. Ariizumi     

IgG4相关腹部疾病的临床及影像学表现

目的 探讨IgG4相关腹部疾病的临床及影像学表现,提高对该病的认识及诊断水平.方法 回顾性分析2012年10月至2021年1月首都医科大学附属北京佑安医院28例IgG4相关腹部疾病的临床及影像学资料.结果 腹部多个器官(2～5个)受累多见,胆管(100.0％)和胰腺(85.7％)最常受累.胆管受累复杂多样,胆总管下段受...     

Intraductal papillary-mucinous adenoma developed in the ventral pancreas in a patient with pancreas divisum

A 34-year-old man was admitted to our hospital with the chief complaints of back pain and epigastralgia. The physical examinations on admission disclosed no abdominal tumor. The serum concentration of total bilirubin was 1.4mg/dl. The serum elastase-1 level was elevated to 526ng/dl. Computed tomography showed a cystic lesion, 1cm in diameter, in the head of the pancreas, without dilatation of the main pancreatic duct. Endoscopic retrograde cholangiopancreatography via the papilla of Vater and the accessory papilla revealed an enlarged ventral pancreatic duct and pancreas divisum. The preoperative diagnosis was mucin-producing pancreatic tumor in the ventral pancreas of a patient with pancreas divisum. A pylorus-preserving pancreatoduodenectomy was performed. The gross findings of the cut surface of the resected specimen disclosed mural nodules in the dilated duct of the ventral pancreas. A histological examination of the mural nodules in the ventral pancreas revealed mucin and intraductal papillary adenoma. Benign tumors associated with pancreas divisum are rare; to the best of our knowledge, only three cases have been reported. Although in these three patients the tumor developed in the dorsal pancreas, the tumor developed in the ventral pancreas in our patient.     

MRI对自身免疫性胰腺炎的诊断价值

目的探讨自身免疫性胰腺炎的MRI表现特征。方法对临床证实的8例自身免疫性胰腺炎患者的MRI资料进行回顾性分析。结果8例自身免疫性胰腺炎患者的MRI影像上表现为胰腺弥漫性肿大,T1WI均匀或不均匀降低,T2WI均匀或不均匀增高;动态增强扫描见动脉期强化不明显,门静脉期及延时期进行性的轻度强化,胰腺周围可见包膜样环状强化影,强化程度略低于胰腺实质;胰管不均匀狭窄。结论自身免疫性胰腺炎是一种特殊类型的慢性胰腺炎,其MRI表现具有特征性,对指导临床诊断和治疗有一定的意义。     

Complete obstruction of the lower common bile duct caused by autoimmune pancreatitis: is biliary reconstruction really necessary?

Recent observations suggest that an immune response is involved in the development of chronic pancreatitis. We report a case of autoimmune pancreatitis in a patient who showed complete obstruction of the lower common bile duct. A 63-year-old man was admitted to a local hospital, complaining of appetite loss and back pain. The patient had obstructive jaundice, and percutaneous transhepatic gallbladder drainage was performed. Fluorography through the biliary drainage catheter showed complete obstruction of the lower common bile duct. The patient had no history of alcohol consumption and no family history of pancreatic disease. Physical examination revealed an elastic hard mass palpable in the upper abdomen. Abdominal ultrasound and abdominal computed tomography (CT) scans showed enlargement of the pancreas head. While autoimmune pancreatitis was highly likely, due to the patients high serum immunoglobulin level, the possibility of carcinoma of the pancreas and/or lower common bile duct could not be ruled out. Laparotomy was performed, and wedge biopsy samples from the pancreas head and body revealed severe chronic pancreatitis with infiltration of reactive lymphocytes, a finding which was compatible with autoimmune pancreatitis. Cholecystectomy and biliary reconstruction, using choledochojejunostomy, were performed, because the complete bile duct obstruction was considered to be irreversible, due to severe fibrosis. After the operation, prednisolone (30mg/day) was given orally for 1 month, and the entire pancreas regressed to a normal size. Complete obstruction of the common bile duct caused by autoimmune pancreatitis has not been reported previously; this phenomenon provides an insight into autoimmune pancreatitis and provokes a controversy regarding whether biliary reconstruction is needed for the treatment of complete biliary obstruction caused by autoimmune pancreatitis.     

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。     

Intraductal mucinous tumor of the pancreas: report of a clinical case

A 49-year-old diabetic patient with abdominal pain was found at ultrasonography and computed tomography to have a cystic mass in the head of the pancreas with dilatation of the main pancreatic duct. The head of the pancreas and the duodenum were removed surgically. Examination of the operative specimen showed chronic pancreatitis, dilatation of the main pancreatic duct, and impacted mucus in the secondary ducts with villous proliferation of the ductal epithelium, thus allowing a diagnosis of intraductal adenomatosis. There was no evidence of malignancy. The resection margin was involved, and consequently the remainder of the pancreas was removed six months after the initial surgical procedure. A review of the literature showed that intraductal adenomatosis tends to spread and carries a high risk of malignant transformation. Surgery is required because of the risk of pancreatic duct obstruction and pancreatic cancer. Intraductal papillary tumour of the pancreas shares many characteristic with other adenomatous proliferation of the gastrointestinal tract (colorectal villous adenoma, bile duct adenomatosis) including the presence of villous structures with increased mucus production, a tendency to spread massively, and a high risk of malignant transformation.     

Minute pancreatic carcinoma with initial symptom of acute pancreatitis

We experienced a case of minute pancreatic carcinoma in a 59-year-old man who complained of upper abdominal pain after drinking alcohol. Abdominal ultrasonography (US) revealed dilatation of the main pancreatic duct (MPD). Abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) showed slight dilatation of the MPD and its obstruction near the portal vein. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated occlusion of the MPD, and cytology of aspirated pancreatic juice was negative for malignancy. With the diagnosis of benign localized obstruction of the MPD, the patient underwent surgery. There was a clear demarcation of hardness and color of the pancreas on the left margin of the superior mesenteric vein, and the caudal pancreas was hard and fibrotic. Intraoperative US revealed slight dilatation of the MPD, and the aspiration cytology result was class IV. First, segmental resection of the pancreas was performed, but pathological examination of frozen section showed neither malignancy nor stenotic lesion. An additional small portion of the proximal pancreas was resected. The specimen included a ductal carcinoma, 5 mm in diameter. Accordingly, a pylorus-preserving pancreatoduodenectomy was performed. Microscopically, the minute carcinoma had already penetrated the duct wall and infiltrated lymph vessels and veins. The patient has been under close observation at our outpatient clinic, and so far there have been no signs of recurrence. To improve the poor prognosis of pancreatic cancer, we should be alert to the occurrence of acute pancreatitis as an initial symptom. Received: December 31, 2001 / Accepted: June 10, 2002 Offprint requests to: M. Imamura     

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。     

Pancreatobiliary fistula associated with an intraductal papillary-mucinous pancreatic neoplasm manifesting as obstructive jaundice: Report of a case

We report a pancreatobiliary fistula caused by an intraductal papillary-mucinous pancreatic neoplasm (IPMN), manifesting as obstructive jaundice. Computed tomography showed dilatation of the bile duct and main pancreatic duct, with multiple cystic masses in the head of the pancreas. Endoscopic retrograde pancreatocholangiography showed a patulous papilla with mucin secretion. Contrast enhancement outlined amorphous material obstructing the lower part of the common hepatic duct. Pancreatogram and magnetic resonance cholangiopancreatography showed diffuse dilatation of the main pancreatic duct and side branches without communication with the adjacent organs or duct. We performed pancreaticoduodenectomy for IPMN of the pancreatic head and a tumor-like lesion in the lower common bile duct (CBD). Macroscopically, impacted thick mucus protruded into the CBD from the pancreas via a pancreatobiliary fistula. Histologic examination revealed a pancreatobiliary fistula caused by intraductal papillary-mucinous carcinoma of the pancreas with mucin hypersecretion, an adenoma without interstitial infiltration, and isolated implantation of an IPMN in the bile duct mucosa around the fistula.     

Mucinous carcinoma of Vater's ampulla with a unique extension along the main pancreatic duct

We report a case of mucinous carcinoma of Vater's ampulla with a unique extension along only the main pancreatic duct (MPD) and microinvasion to the pancreas. A 52-year-old man was referred to our hospital for the evaluation and treatment of acute pancreatitis. Abdominal computed tomography (CT) demonstrated swelling in the head of the pancreas with a mass in the duodenum. Hypotonic duodenography and endoscopic examination revealed a well-defined mass, measuring about 25 mm in size, in Vater's ampulla. A biopsy specimen of the tumor showed moderately differentiated adenocarcinoma. A pylorus-preserving pancreaticoduodenectomy with a regional lymphadenectomy was performed, under a preoperative diagnosis of adenocarcinoma of Vater's ampulla with direct invasion into the head of the pancreas. The resected specimen of the duodenum confirmed the presence of the mass, which measured 22 × 15 mm in size, in Vater's ampulla. Microscopically, the tumor consisted of two components: moderately differentiated adenocarcinoma in the peripheral region of the tumor Vater's papilla and mucinous carcinoma in the central region of the tumor. The mucinous carcinoma component uniquely extended along only the MPD with microinvasion to the pancreas. Immunohistochemically, both the moderately differentiated adenocarcinoma and the mucinous carcinoma were positive for cytokeratin 20 (CK20) and negative for cytokeratin 7 (CK7) which is the pattern of intestinal-type carcinoma of Vater's ampulla. We concluded that the original site of this tumor may have been the duodenal epithelium of Vater's ampulla originally moderately differentiated adenocarcinoma—which subsequently changed to mucinous carcinoma that extended along only the MPD with microinvasion to the pancreas.     

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.     

Utility of preoperative dynamic magnetic resonance imaging of the pancreas in diagnosing tumor-forming pancreatitis that mimics pancreatic cancer: Report of a case

The differential diagnosis of pancreatic carcinoma and tumor-forming pancreatitis remains difficult, and this situation can cause serious problems because the management and prognosis of these two focal pancreatic masses are entirely different. We herein report a case of tumor-forming pancreatitis that mimics pancreatic carcinoma in an 80-year-old woman. Computed tomography showed a solid mass in the head of the pancreas, and endoscopic retrograde cholangiopancreatography showed a complete obstruction of the main pancreatic duct in the head of the pancreas. Dynamic contrastenhanced magnetic resonance imaging (MRI) demonstrated a time-signal intensity curve (TIC) with a slow rise to a peak (1 min after the administration of the contrast material), followed by a slow decline at the pancreatic mass, indicating a fibrotic pancreas. Under the diagnosis of tumor-forming pancreatitis, the patient underwent a segmental pancreatectomy instead of a pancreaticoduodenectomy. The histopathology of the pancreatic mass was chronic pancreatitis without malignancy. The pancreatic TIC obtained from dynamiccontrast MRI can be helpful to differentiate tumor-forming pancreatitis from pancreatic carcinoma and to avoid any unnecessary major pancreatic surgery.     

Intraductal papillary-mucinous tumor of the pancreas head with complete absence of the ventral pancreatic duct of Wirsung

A case of intraductal papillary mucinous tumor of the pancreas with complete absence of the ventral pancreatic duct of Wirsung is presented. A 74-year-old Japanese man was admitted to our hospital because of elevated serum amylase concentration. Abdominal computed tomography (CT) scanning revealed diffuse dilatation of the main pancreatic duct and a diffuse and uncircumscribed area with heterogeneous density in the pancreas head. Endoscopic retrograde cholangiopancreatography revealed that the main pancreatic duct was connected with an accessory papilla and was diffusely dilated, without any irregularity of the duct wall being observed in the entire length of the duct. The common bile duct was detected only by cannulation through Vaters papilla, and no pancreatic duct or its communicating branch was found. Some branches, directed to the dorsal portion of the pancreas head, were found arising from the accessory pancreatic duct. Intraductal ultrasound examination performed through the accessory papilla and the common bile duct revealed a small tumor with a heterogeneous echo level in the pancreas head. From these findings, intraductal papillary-mucinous tumor (IPMT) occurring in the pancreas head was diagnosed, and pylorus-preserving pancreaticoduodenectomy was performed. The resected specimen revealed IPMT in the pancreas head. A roentgenographic study of the resected specimen revealed a defect caused by the tumor located in the pancreatic duct connected with the accessory papilla and showed that there was complete absence of the pancreatic duct connected with Vaters papilla. Surgical resection enabled us to completely analyze the duct system of pancreas divisum. Although it is not known whether there is a relationship between the pathogenesis of IPMT and embryological anomaly of the pancreatic duct system, this case may provide an insight into the pathogenesis of IPMT.     

Diagnosis of autoimmune pancreatitis with cholesterol granuloma mimicking intraductal papillary-mucinous carcinoma: A case report

IntroductionPancreatic cysts are often observed incidentally on abdominal computed tomography (CT). For cysts involving intracystic nodules, malignant neoplasms such as intraductal papillary-mucinous carcinoma (IPMC) should be suspected. In contrast, cholesterol granuloma (CG) rarely occurs in the pancreas, and CG-associated autoimmune pancreatitis (AIP) has not yet been reported. To our knowledge, this is the first reported case of AIP with CG mimicking IPMC.Presentation of caseA 56-year-old woman underwent abdominal CT for preoperative breast cancer screening. Asymptomatic polycystic lesions were detected in the pancreatic tail (maximum diameter, 5 cm). Magnetic resonance cholangiopancreatography and endoscopic ultrasonography revealed main pancreatic duct obstruction and a lesion with intracystic nodules (maximum diameter, 10 mm). Serum levels of pancreatic cancer tumor markers and IgG4 were within normal ranges. Because IPMC was suspected, distal pancreatectomy and splenectomy with regional lymphadenectomy were performed after surgery for breast cancer. Pathological examination of the specimen revealed no epithelial neoplasm; however, cholesterol crystals with foreign body giant cells were observed. Moreover, IgG4-positive plasma cells, diffuse lymphocyte infiltration, storiform fibrosis, and obliterative phlebitis were identified in the non-cystic pancreatic parenchyma. The final diagnosis was AIP with CG.DiscussionCG in the pancreas is rare and its pathogenesis remains unclear. The findings of the present case suggest that chronic inflammation due to AIP may cause local bleeding, and that a reaction to the leaked blood cells causes CG.ConclusionsAlthough preoperative diagnosis may be difficult, AIP with CG should be considered as a differential diagnosis in pancreatic cysts involving nodular lesions.