Intrapancreatic gastric duplication cyst mimicking pancreatic cystic tumor

Cystic lesions of the pancreas are sometimes difficult to diagnose. We report a case of a gastric duplication cyst (GDC) of the pancreas in an adult. A 45-year-old woman was admitted to our department for the investigation of anemia. Abdominal ultrasonography revealed a large cystic lesion, measuring about 40 × 70 mm with calcification in the tail of the pancreas. Contrast-enhanced computed tomography of the abdomen revealed a non-enhanced cystic lesion with non-enhanced wall. Endoscopic retrograde pancreatography revealed a mild extended main pancreatic duct and an aberrant pancreatic duct, but there was no communication with the cyst. We could not deny the malignancy, so distal pancreatectomy was performed. The pathological examination revealed that the inner wall of the cyst consisted of columnar epithelium and smooth muscle layer. Immunohistochemical analysis revealed the columnar epithelium to be immunopositive for cytokeratin 7 (CK7) and immunonegative for cytokeratin 20 (CK20) and the glands to be immunonegative for CK 7 and immunopositive for CK 20. Therefore, a diagnosis of GDC of the pancreas was made. On imaging, a GDC usually mimics a pancreatic pseudocyst or a cystic neoplasm of the pancreas. Therefore, even though it is rare, a GDC should be considered in the differential diagnosis of cystic tumors of the pancreas.     

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.     

Coexisting Type 1 Autoimmune Pancreatitis and Mixed-type Intraductal Papillary Mucinous Neoplasm

An 84-year-old man was referred to our hospital for a cystic lesion of the pancreatic head, swelling of the pancreatic tail and hilar biliary stricture, resulting in elevated liver enzyme levels. We suspected branch duct-type intraductal papillary mucinous neoplasm (IPMN) and type I autoimmune pancreatitis (AIP) associated with sclerosing cholangitis because of the high serum IgG4 levels. The main pancreatic duct on the tail side of the AIP lesion was moderately dilated. Although the biliary stricture and pancreatic swelling improved after prednisolone treatment, the pancreatic enzyme levels increased rapidly. The entire main pancreatic duct exhibited remarkable dilatation, which led to the diagnosis of mixed-type IPMN. The clinical characteristics of IPMN in the main pancreatic duct appear to have been initially masked by AIP.     

Difficulty in diagnosing autoimmune pancreatitis by imaging findings

BACKGROUND: 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. OBJECTIVE: To clarify a variety of imaging findings of AIP and the reason for its misdiagnosis. DESIGN: We examined the imaging findings of 37 AIP cases and also examined misdiagnosed cases of AIP to determine their reasons for misdiagnosis. PATIENTS: A total of 37 patients with AIP who reported to our hospital or its affiliate over a 17-year period (1989 to May 2005). RESULTS: 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. CONCLUSIONS: 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.     

A giant retention cyst of the pancreas (cystic dilatation of dorsal pancreatic duct) associated with pancreas divisum

We describe a rare case of pancreas divisum associated with a giant retention cyst (cystic dilatation of the dorsal pancreatic duct), presumably formed following obstruction of the minor papilla. The patient was treated by pancreatico(cysto)jejunostomy. A 50-year-old man was admitted with complaints of increasing upper abdominal distension and body weight loss. There was no previous history of pancreatitis, gallstones, drinking, or abdominal injury. An elastic-hard tumor-like resistance was palpable in the upper abdomen. Computed tomography and ultrasound (US) examinations revealed a giant cystic lesion expanding from the pancreas head to the tail. Endoscopic retrograde cholangiopancreatography findings showed a looping pancreatic duct which drained only the head and uncinate process of the pancreas to the main papilla. A US-guided puncture to the cystic lesion revealed that the lesion continued to the main pancreatic duct in the tail of pancreas. The lesion was connected to a small cystic lesion, which was located inside the minor papilla, and ended there. The amylase level in liquid aspirated from the cyst was 37 869 IU/l, and the result of cytological examination of the liquid showed class II. A pancreatico(cysto)jejunostomy was performed, with the diagnosis being pancreas divisum associated with a retention cyst following obstruction of the minor papilla. The histological findings of a specimen from the cyst wall revealed that the wall was a pancreatic duct covered with mildly inflammatory duct epithelium; there was no evidence of neoplasm. The patient is currently well, and a CT examination 2 years after the operation showed disappearance of the cyst and normal appearance of the whole pancreas. Received: April 24, 2001 / Accepted: September 14, 2001     

Small nodules which could indicate the early phase of autoimmune pancreatitis

We present a case with small pancreatic nodules, which could indicate the early phase of autoimmune pancreatitis (AIP). A 68-year-old man was referred to our hospital for further diagnostic evaluation of a pancreatic mass detected on abdominal ultrasonography screening for epigastric discomfort. Abdominal ultrasonography and endoscopic ultrasonography revealed a low echoic lesion measuring approximately 1 cm with an irregular margin in the body of the pancreas. Computed tomography revealed a tumor in the portal venous phase of enhancement; hence, a distal pancreatectomy was performed. On histology, a marked lymphocyte- and plasma cell-dominant inflammatory cell infiltrate was observed in the nodule. There was another smaller nodule consisting of moderate lymphoplasmacytic infiltration in the 2-cm distal portion of the pancreas. Lymphoplasmacytic infiltration was also observed around the main pancreatic duct in the pancreatic stump. In the parenchyma, other than these 3 portions, the normal lobular structure was well preserved. Little storiform fibrosis and obliterative phlebitis were observed in the resected specimen. On immunohistochemical staining, plasma cells showing strong immunoreactivity for immunoglobulin G4 were observed within these two nodules and around the main pancreatic duct at the cut surface. This case could indicate the early phase and multicentricity of AIP.     

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

We herein report a unique form of autoimmune pancreatitis (AIP) spreading along the main pancreatic duct (MPD). A 70-year-old man was referred for a small lesion at the pancreatic neck, accompanying an adjacent cyst and dilated upstream MPD. Four years earlier, health checkup images had shown a pancreatic cyst but no mass lesion. Endoscopic ultrasonography showed a contrast-enhanced, tumorous lesion, mainly occupying the MPD. With a preoperative diagnosis of ductal neoplasms mainly spreading in the MPD, Whipple''s resection was performed. The resected specimens showed MPD periductitis with IgG4-related pathology, indicating type 1 AIP. Clinicians should practice caution concerning the various AIP forms.     

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.     

Lymphoepithelial cyst of the pancreas

We experienced a rare case of lymphoepithelial cyst of pancreas. The patient was a 68-year-old man in whom a cystic lesion in the pancreas was detected when he was admitted for chronic renal failure. On ultrasonography, we detected a cystic lesion, 3 cm in diameter, with a septum, in head and body of the pancreas. On both computed tomography and magnetic resonance imaging, the cystic lesion did not show solid components. Endoscopic retrograde cholangiopancreatography showed no abnormality in the pancreatic duct and did not detect the cystic lesion. Although the lesion showed no evidence of malignancy on the images, we could not rule out malignancy, since high levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were detected. We therefore performed a pancreatoduodenectomy. In the resected specimen, the lesion was a well-circumscribed and multilocular cyst that contained yellowish-white keratinous material and had no solid components. Histologically, the cyst wall was composed of mature keratinizing squamous epithelium and lymphoid tissue; it was diagnosed as a benign lymphoepithelial cyst of the pancreas.     

MANAGEMENT STRATEGIES FOR BRANCH DUCT INTRADUCTAL PAPILLARY‐MUCINOUS NEOPLASMS

Management strategies for branch duct intraductal papillary‐mucinous neoplasms (IPMN) have been discussed. The authors’ clinical criteria with special attention to the size of cystic lesion, the diameter of main pancreatic duct, and the size of mural nodule established in 2001 is useful for managing branch duct IPMN. A total of 55 of 60 cases with branch duct IPMN had no radiologic progression during an average follow up of 701 days. In addition, no case out of 27 cases with branch duct IPMN followed up for 3 years changed to positive in cytological examination using pancreatic juice. There were four cases of branch type IPMN with some changes in their image findings. There were two cases of branch type IPMN with pancreatic symptoms. A total of three out of these five cases were surgically resected. The ordinary‐type ductal carcinoma was detected in two cases with branch duct IPMN at 3 or 4 years later. These results suggest that a long‐term careful follow‐up study by computed tomography or ultrasonography at every 6 months would be needed in the management of branch duct IPMN. Further studies will be needed to dissolve this problem in the future.     

Epidermoid cyst of the intrapancreatic accessory spleen producing CA19‐9

We report a rare case of an epidermoid cyst in an accessory spleen at the pancreatic tail with producing CA19‐9. A 55‐year‐old female was admitted to our hospital, Cancer Research Institute, Kanazawa University, for close examination of a cystic lesion at the pancreatic tail and a high serum CA19‐9‐value (176 U/mL). There were almost no abdominal symptoms related to the cystic lesion. A cystic tumor approximately 3 cm in diameter and composed of multilocular cysts without a protruding portion of the inner surface was found at the pancreatic tail by ultrasound sonography, computed tomography, and magnetic resonance imaging. Endoscopic retrograde pancreatography revealed that the main pancreatic duct shifted at the pancreatic tail and there was no communication between the main pancreatic duct and cystic lesion. Based on a preoperative diagnosis of mucinous cystic tumor, distal pancreatectomy with splenectomy was performed. Histological ?ndings suggested an epidermoid cyst (3.5 × 3.0 cm) originating from an intrapancreatic accessory spleen. Immunohistochemical analysis of CA19‐9 in the epidermoid cyst showed clear staining of the inner epithelium of the cyst and amorphous or hyalinous cystic contents. The serum CA19‐9 value was con?rmed to decline to normal 2 months after resection. Physicians should not forget this disease during differential diagnosis related to pancreatic cystic lesions with elevated levels of serum tumor markers, such as CA19‐9 or carcinoembryonic antigen, although this disease is extremely rare.     

Mucinous cystadenoma of the pancreas 17 years after excision of gallbladder because of a choledochal cyst

A 56-year-old woman who had undergone excision of the gallbladder because of a choledochal cyst had a tumorous lesion of the pancreas identified by upper abdominal ultrasonography, but an operation was not carried out, because there was no apparent increase in the cystic mass and no elevation of serum tumor markers. In October 2001, she was admitted to our hospital to check for malignancy because of elevated levels of the tumor marker Dupan-2. Abdominal enhanced computed tomography and upper abdominal ultrasonography revealed a large multilocular cystic mass in the body to tail of the pancreas. Endoscopic retrograde cholangiopancreatography showed elongation of the common duct that communicates with the common bile duct and the main pancreatic duct, indicating an anomalous arrangement of the biliary and pancreatic duct system. No apparent communications between the cystic mass and the main pancreatic duct were observed. In January 2002, the patient underwent a spleen-preserving distal pancreatectomy, and histopathological and immunohistochemical examinations led to the diagnosis of pancreatic mucinous cystadenoma with ovarian-like stroma. The mucinous cystadenoma was detected 17 years after the operation for the choledochal cyst. To the best of our knowledge, no documented case reports of mucinous cystadenoma of the pancreas associated with a choledocal cyst have been reported to date. We present here the first case report of pancreatic mucinous cystadenoma occurring in the body to tail of the pancreas, associated with a choledocal cyst.     

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.     

中老年人自身免疫性胰腺炎的磁共振表现

目的 探讨中老年人自身免疫性胰腺炎(AIP)的磁共振(MRI)特征. 方法 17例经组织学或类固醇激素治疗证实的中老年AIP患者,均接受MRI检查,对患者的临床和MRI资料进行回顾性分析. 结果 17例中老年AIP中,13例AIP表现为胰腺弥漫性肿大,4例为局限性肿大或局限性信号异常.病变T_1WI上呈明显低信号,在T_2WI上呈轻度高信号,动脉期强化减弱但呈现明显的延时强化.13例在胰腺病变周围环绕包膜样结构.15例AIP伴有胰腺段胆总管的狭窄,5例胰胆管磁共振显示胰管不规则狭窄.11例AIP的平均表观扩散系数值为1.64×10~3mm~2/s. 结论 AIP好发于中老年人;其MRI特征包括胰腺呈香肠样或香蕉样肿大、病变胰腺周围延迟强化的包膜样影、胰管弥漫不规则狭窄等,MRI既可用于诊断AIP,也是评价其疗效的重要手段.     

Endoscopic approach for diagnosing autoimmune pancreatitis

It is of utmost importance to differentiate autoimmune pancreatitis (AIP) from pancreatic cancer (PC). Segmental AIP cases are sometimes difficult to differentiate from PC. On endoscopic retrograde cholangiopancreatography, long or skipped irregular narrowing of the main pancreatic duct (MPD), less upstream dilatation of the distal MPD, side branches derived from the narrowed portion of the MPD, absence of obstruction of the MPD, and stenosis of the intrahepatic bile duct suggest AIP rather than PC. Abundant infiltration of IgG4-positive plasma cells is frequently and rather specifically detected in the major duodenal papilla of AIP patients. IgG4-immunostaining of biopsy specimens obtained from the major duodenal papilla is useful for supporting a diagnosis of AIP with pancreatic head involvement. On endoscopic ultrasonography (EUS), hyperechoic spots in the hypoechoic mass and the duct-penetrating sign suggest AIP rather than PC. EUS and intraductal ultrasonography sometimes show wall thickening of the common bile duct even in the segment in which abnormalities are not clearly observed with cholangiography in AIP patients. EUS-guided fine needle aspiration, especially EUS-guided Tru-Cut biopsy, is useful to diagnose AIP, as well as to exclude PC.     

Cyst fluid SPINK1 may help to differentiate benign and potentially malignant cystic pancreatic lesions

ObjectiveDifferential diagnosis between benign and potentially malignant cystic pancreatic lesions may be difficult. Previously we have compared cyst fluid serine protease inhibitor Kazal type I (SPINK1) with some traditionally used tumour markers (amylase, CEA, Ca19-9) and found that it may be a new promising maker in the differential diagnosis of cystic pancreatic lesions. In the present study, we focused on cyst fluid SPINK1 levels in benign and potentially malignant cystic pancreatic lesions.DesignSixty-one patients operated on for cystic pancreatic lesion in Tampere University Hospital, Finland and in Verona University Hospital, Italy, were included. Cyst fluid was aspirated during surgery, stored at ?70 °C, and analysed with immunofluorometric assay for SPINK1. The final diagnosis was acute pancreatitis with fluid collection (Acute FC) in 4 patients, chronic pseudocyst (PS) in 17 patients, serous cystadenoma (SCA) in 7 patients, mucinous cystadenoma (MCA) in 21 patients and intraductal papillary-mucinous neoplasm (IPMN) in 12 patients (9 main/mixed duct type and 3 branch duct type).ResultsThe acute FC patients had high SPINK1 levels. Among chronic cysts, SPINK1 levels were significantly higher in patients with potentially malignant cysts (main/mixed duct IPMN and MCA) than with benign cysts (side branch IPMN and SCA), (median and range, [480 (13–3602) vs. 18 (0.1–278) μg/L]; p < 0.0001). In the subcohort of 24 patients with <3 cm chronic cyst, cyst fluid SPINK 1 levels were significantly lower in SCA or side branch IPMN (3 [2–116] μg/L) than in main duct IPMN or MCA (638 [66–3602] μg/L; p = 0.018). The best sensitivity and specificity to differentiate any size MCA or main/mixed type IPMN from SCA or side branch IPMN were 85% and 84% (AUC 0.94; cut-off value 118 μg/L). The best sensitivity and specificity to differentiate <3 cm MCA or main duct IPMN from SCA or side branch IPMN were 93% and 89% (AUC 0.98; cut-off value 146 μg/L).ConclusionsCyst fluid SPINK1 may be a possible marker in the differential diagnosis of benign and potentially malignant cystic pancreatic lesions.     

Autoimmune pancreatitis associated with a large pancreatic pseudocyst

INTRODUCTIONAutoimmune pancreatitis (AIP) is a benign disease that responds well to steroid treatment. Characteristics in-clude radiological evidence of an irregular narrowing of the pancreatic main duct and a diffuse enlargement of the pancreas, together…     

Focal ductal branch dilatation on magnetic resonance cholangiopancreatography: a hint for early diagnosis of pancreatic carcinoma

A 63-year-old man with a combination of early pancreatic carcinoma and an intraductal papillary adenoma was reported. A pancreatic cyst was detected by chance at the head of the pancreas by computed tomography for a follow-up study of early rectal carcinoma previously operated. Detailed studies by endoscopic retrograde pancreatography (ERP) showed irregular narrowing of the main pancreatic duct at the pancreatic body and magnetic resonance cholangiopancreatography (MRCP) revealed dilatation of ductal branches draining there. Brushing cytology of the pancreatic duct demonstrated cancer cells and total pancreatectomy was performed. Stepwise histo-pathological examinations of the specimen showed two foci of invasive carcinoma in the neck and body and multiple foci of severe dysplasia, some of which contained carcinoma in situ, in the body of the pancreas. The cystic tumor in the head of the pancreas was an intraductal papillary adenoma. In this case, the scrutiny of a pancreatic cyst including MRCP and ERP led to an early diagnosis of pancreatic cancer. Dilatation of ductal branches depicted by MRCP might be a new hint for early diagnosis of pancreatic carcinoma.     

Focal Ductal Branch Dilatation on Magnetic Resonance Cholangiopancreatography: A Hint for Early Diagnosis of Pancreatic Carcinoma

A 63-year-old man with a combination of early pancreatic carcinoma and an intraductal papillary adenoma was reported. A pancreatic cyst was detected by chance at the head of the pancreas by computed tomography for a follow-up study of early rectal carcinoma previously operated. Detailed studies by endoscopic retrograde pancreatography (ERP) showed irregular narrowing of the main pancreatic duct at the pancreatic body and magnetic resonance cholangiopancreatography (MRCP) revealed dilatation of ductal branches draining there. Brushing cytology of the pancreatic duct demonstrated cancer cells and total pancreatectomy was performed. Stepwise histo-pathological examinations of the specimen showed two foci of invasive carcinoma in the neck and body and multiple foci of severe dysplasia, some of which contained carcinoma in situ, in the body of the pancreas. The cystic tumor in the head of the pancreas was an intraductal papillary adenoma. In this case, the scrutiny of a pancreatic cyst including MRCP and ERP led to an early diagnosis of pancreatic cancer. Dilatation of ductal branches depicted by MRCP might be a new hint for early diagnosis of pancreatic carcinoma.     

Clinical difficulties in the differentiation of autoimmune pancreatitis and pancreatic carcinoma

OBJECTIVES: Autoimmune pancreatitis (AIP) is a newly described entity with characteristic clinical, histologic, and morphologic changes, in which autoimmune mechanisms are involved in pathogenesis. However, difficulties can arise in the differentiation of AIP from pancreatic carcinoma. The aims of this study were to clarify clinical and radiologic features of AIP to elucidate areas of diagnostic confusion. METHODS: Clinical, serologic, and radiologic findings were evaluated in 17 patients with AIP. RESULTS: All 17 patients were initially suspected to have pancreatic carcinoma. The patients were predominantly elderly men who frequently presented with jaundice but without features of acute pancreatitis. Elevation of serum gamma-globulin and IgG along with the presence of autoantibodies were usually evident, whereas serum tumor markers were elevated in 54% of cases. Stenosis of the bile duct was detected in 94% of cases. Diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct were radiologically characteristic; however, segmental swelling and narrowing were detected in seven and two patients, respectively. In segmental cases, neither atrophy of the distal pancreas nor marked upstream dilation of the distal main pancreatic duct was observed.Angiographic abnormalities occurred in 54% of cases. Serologic and radiologic abnormalities showed considerable improvement with steroid therapy. CONCLUSIONS: Frequent stenosis of the bile duct, elevation of serum tumor markers, segmental pancreatic enlargement or narrowing of the main pancreatic duct, and angiographic abnormalities can cause confusion in the differential diagnosis of AIP and pancreatic carcinoma.