Autoimmune pancreatitis detected as a mass in the head of the pancreas with contiguous fibrosis around the superior mesenteric artery

Autoimmune pancreatitis mimicking pancreatic cancer

BACKGROUND/PURPOSE

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that can often be difficult to distinguish from pancreatic cancer. We describe the clinical and radiographic features of 23 patients with AIP whose presentations mimicked pancreatic cancer.

METHODS

A review of clinic, radiology, and endoscopy records from a 6-year period identified patients with AIP initially suspected of having pancreatic cancer. Abdominal computed tomography (CT) with intravenous contrast, endoscopic ultrasonography (EUS), and/or ERCP was performed in each patient. The diagnosis of AIP was made histologically and/or cytologically for each patient.

RESULTS

Nineteen of 23 patients (83%) presented with new-onset weight loss, jaundice, or both. Nineteen (83%) patients had CT findings worrisome for pancreatic cancer including: (1) pancreatic enlargement or focal mass, (2) regional lymphadenopathy, and/or (3) vascular invasion. Eighteen patients (78%) had common bile duct strictures on ERCP. EUS-guided fine-needle aspiration biopsies excluded pancreatic cancer in all 22 patients who had EUS (96%). Seven patients had surgery for continued suspicion of pancreatic cancer.

CONCLUSIONS

Although AIP commonly presents with features suggestive of pancreatic cancer, clinical recognition of AIP with appropriate diagnostic testing including EUS with fine-needle aspiration, ERCP, IgG4 levels, and pancreatic protocol CT expedites diagnosis and can spare patients unnecessary surgery.

Pancréatite auto-immune

Chronic autoimmune pancreatitis is an entity distinct from all other forms of chronic pancreatitis. It is expressed by signs of acute or chronic pancreatitis, sometimes associated with cholestatic jaundice. In imaging, it may appear as diffuse (duct destructive) or pseudotumoral lesions. These 2 aspects are probably different clinical forms of chronic autoimmune pancreatitis. Some autoimmune diseases are associated with chronic autoimmune pancreatitis, but not consistently. One such disease involves a bile disorder very similar to primary sclerosing cholangitis but responsive to corticosteroid treatment. Pancreatitis may be a sign of intestinal inflammatory diseases (and vice versa): testing for Crohn's disease and ulcerative rectocolitis is justified in patients with idiopathic pancreatitis. Chronic autoimmune pancreatitis must be routinely considered in patients with a pancreatic tumor that is for a clinical, epidemiologic, serologic or imaging reason not completely consistent with pancreatic adenocarcinoma. A short corticosteroid therapy (< 4 weeks) is probably less harmful in a patient with pancreatic adenocarcinoma than pancreatectomy (or chemotherapy) in patients with chronic autoimmune pancreatitis. Diagnosis depends on a body of clinical and radiologic evidence. The diagnostic value of serologic markers and especially of autoantibodies must be clarified in the future.

Autoimmune pancreatitis: radiologic findings in 20 patients

BACKGROUND

Autoimmune pancreatitis is a new clinical entity that is characterized by peculiar histopathologic and laboratory findings and by a dramatic clinical response to corticosteroid therapy. We evaluated the radiologic findings of autoimmune pancreatitis.

METHODS

Computed tomographic, magnetic resonance imaging, endoscopic retrograde cholangiopancreatographic, and ultrasonographic findings of 20 patients with autoimmune pancreatitis in our hospital between November 2000 and December 2003 were retrospectively reviewed regarding changes and ancillary findings in the pancreatic parenchyma, the main pancreatic duct, peripancreatic vessels, and distal common bile duct. In addition, follow-up images were reviewed for changes in any abnormality seen on the initial examinations.

RESULTS

Pancreatic parenchymal enlargement was invariably seen that was diffuse (n = 19) or focal (n = 1), with homogeneous contrast enhancement on computed tomography (n = 20) and magnetic resonance imaging (n = 15). Capsule-like rim enhancement was seen in six patients. There was focal (n = 18) or diffuse (n = 2) narrowing of the main pancreatic duct and it was usually multifocal (n = 17) in the former. Narrowing of the peripancreatic veins was seen in 14 patients. There was tapered (n = 15) or abrupt (n = 3) narrowing of the distal common bile duct in 18 patients, with contrast enhancement of the narrowed segment in eight. Invariably, changes in the pancreatic parenchyma, main pancreatic duct, peripancreatic vessels, and common bile duct were normalized on follow-up studies after steroid therapy.

CONCLUSION

In this series, common radiologic findings of autoimmune pancreatitis were (a) diffuse pancreas enlargement, (b) multifocal narrowing of the main pancreatic duct, (c) narrowing of peripancreatic veins, and (d) tapered narrowing of the distal common bile duct with frequent contrast enhancement. These findings were usually reversible with steroid therapy.

Autoimmune pancreatitis

The list of diseases associated with autoantibodies against tissues, cells, or specific autoantigens is growing, and many organs in the body are known to be affected by autoimmune injury. Until recently, the most well-known pancreatic autoimmune disorder was type 1 diabetes mellitus, where there is selective destruction of beta cells in the islets of Langerhans. Although an autoimmune process affecting the exocrine pancreas was suspected over four decades ago, it is only in the past 10 years or so that autoimmune chronic pancreatitis has been recognized as a distinct entity. Here we review the clinical, serologic, radiologic, and histologic features of autoimmune pancreatitis.

Non-alcoholic duct destructive chronic pancreatitis: a histological, immunohistochemical and in-situ apoptosis study of 18 cases

AIMS

To assess retrospectively pancreatic changes in non-alcoholic duct-destructive chronic pancreatitis and to investigate the role of apoptosis in duct destruction.

METHODS AND RESULTS

Eighteen patients (mean age 46 years, nine women and nine men) underwent pancreatic resection for suspected pancreatic tumour and were diagnosed as having non-alcoholic duct-destructive chronic pancreatitis. We performed a morphological study either semiquantitatively (fibrosis and inflammation) or quantitatively (CD3+ intraepithelial lymphocytes, M30 and TUNEL+ apoptotic cells). The results were compared with those obtained in 10 cases of chronic alcoholic pancreatitis and nine cases of chronic obstructive pancreatitis. Pancreatic changes were diffuse and heterogeneous in 14 cases, but segmental in four cases. The main pancreatic lesions were ductal epithelial alteration, periductal inflammation and fibrosis. There were no cysts or calcifications. We found a marked increase in mast cells in the infiltrate, a slight increase in TiA1+ lymphocytes and in intraepithelial lymphocytes compared with other types of chronic pancreatitis. No significant increase in ductal apoptosis was observed.

CONCLUSION

Non-alcoholic duct-destructive chronic pancreatitis is a well-defined pathological entity, distinct from alcoholic and obstructive chronic pancreatitis. Our results indicate that apoptosis probably does not play a major role in ductal alterations.

A cost-minimization analysis of alternative strategies in diagnosing pancreatic cancer

BACKGROUND

Several modalities currently exist for tissue confirmation of suspected pancreatic cancer prior to therapy. Since there is a paucity of cost-minimization studies comparing these different biopsy modalities, we analyzed costs and examined effectiveness of four alternative strategies for diagnosing pancreatic cancer.

METHODS

A decision analysis model of patients with suspected pancreatic cancer was constructed. We analyzed costs, failure rate, testing characteristics, and complication rates of four commonly employed diagnostic modalities: 1) computerized tomography or ultrasound-guided fine-needle aspiration (CT/US-FNA), 2) endoscopic retrograde cholangiopancreatography with brushings (ERCP-B), 3) Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA), and 4) laparoscopic surgical biopsy. If the first attempt with a particular modality failed, a different modality was employed to identify the most preferable secondary biopsy strategy.

RESULTS

This analysis identifies EUS-FNA as the preferred initial modality for the diagnosis of pancreatic cancer. Resultant expected costs and strategies in decreasing optimality include: 1) EUS-FNA (1,405 dollars), 2) ERCP-B (1,432 dollars), 3) CT/US-FNA (3,682 dollars), and 4) surgery (17,711 dollars). If a patient presents with obstructive jaundice, decision analysis modeling resulted in a total expected costs of 1,970 dollars if ERCP-B is successful at the time of biliary stent placement. Additional analyses to identify the preferred follow-up modality after a failed alternative method showed that EUS-FNA is the preferred secondary modality if any of the other three modalities failed first, in both the setting of and absence of obstructive jaundice. One- and two-way sensitivity analysis of the variables shows unchanged results over an acceptable range.

CONCLUSIONS

This cost-minimization study illustrates that EUS-FNA is the best initial and the preferred secondary alternative method for the diagnosis of suspected pancreatic cancer. In addition to local expertise and availability, costs and diagnostic yield should be considered when choosing an optimal diagnostic strategy.

Autoimmune chronic pancreatitis

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis.

T cell lymphoplasmacellular and eosinophilic infiltration of the pancreas with involvement of the gallbladder and duodenum in non-alcoholic duct-destructive chronic pancreatitis

BACKGROUND

Non-alcoholic duct destructive chronic pancreatitis is a rare entity with specific pathological features. The majority of the patients are from Japan. We report a case with involvement of the distal bile duct, the gallbladder, the duodenum and the ampulla, and present a review of patients from Europe and the USA since 1997.

CASE PRESENTATION

A 56-year-old man presented with a 3-month history of mild acute pancreatitis and obstructive jaundice, followed by increasing weight loss, lethargy and epigastric pain. CT showed a mass in the head of the pancreas. ERCP demonstrated a smooth stricture of the intra-pancreatic main bile duct and an irregular, incomplete, stricture in the main pancreatic duct. A pancreatic cancer could not be reliably excluded, and, therefore, he underwent a pylorus-preserving Kausch-Whipple's pancreatoduodenectomy.

RESULTS

Histopathology showed typical peri-ductal T cell-rich lymphoplasmacellular and eosinophilic infiltration of the pancreas, with involvement of the distal bile duct but, also, unusual inflammatory infiltration of the gallbladder, the duodenum and the ampulla.

CONCLUSION

The inflammatory process in non-alcoholic duct-destructive chronic pancreatitis can affect the entire pancreato-biliary region and mimics pancreatic cancer. Currently, there are no definitive criteria for pre-operative diagnosis, so it is very difficult for one to avoid resection.

Contrast-enhanced sonography of autoimmune pancreatitis: comparison with pathologic findings

OBJECTIVE

We evaluated the vascularity of autoimmune pancreatitis lesions on contrast-enhanced harmonic gray scale sonographic images in comparison with the pathologic findings.

METHODS

Six patients with autoimmune pancreatitis were examined. All patients held their breath from 20 to 50 seconds after the injection of a contrast agent while the vascularity of the lesion was examined by contrast-enhanced harmonic gray scale sonography (early phase), and lesion enhancement was monitored at about 90 seconds after the injection while the patients held their breath for a few seconds (delayed phase). We then compared the vascularity on the contrast-enhanced harmonic gray scale sonographic images with the pathologic findings (fibrosis and inflammation) in all lesions. The vascularity of 3 of the 6 lesions was also evaluated by contrast-enhanced harmonic gray scale sonography before and after treatment with corticosteroids.

RESULTS

The autoimmune pancreatitis lesions exhibited mild (n = 1), moderate (n = 3), or marked (n = 2) enhancement throughout almost the entire lesions in both the early and delayed phases. The grade of lesion vascularity on the contrast-enhanced harmonic gray scale sonographic images correlated with the pathologic grade of inflammation and inversely correlated with the grade of fibrosis associated with autoimmune pancreatitis. The vascularity of all 3 lesions had decreased on the contrast-enhanced harmonic gray scale sonographic images after steroid therapy.

CONCLUSIONS

Contrast-enhanced harmonic gray scale sonography may be useful for evaluating the vascularity of autoimmune pancreatitis lesions and the therapeutic efficacy of steroid therapy.

Involvement of the biliary system in autoimmune pancreatitis: a follow-up study

BACKGROUND & AIMS

The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis.

METHODS

Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients.

RESULTS

Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved.

CONCLUSIONS

Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

High prevalence of autoantibodies against carbonic anhydrase II and lactoferrin in type 1 diabetes: concept of autoimmune exocrinopathy and endocrinopathy of the pancreas

INTRODUCTION

Dysfunction of the exocrine as well as the endocrine pancreas has been reported in type 1 diabetes. Lymphocytic infiltration of the exocrine pancreas is observed in approximately half of Japanese type 1 diabetic patients.

AIMS

To investigate the involvement of autoimmunity against the exocrine pancreas in type 1 diabetes.

METHODOLOGY

We examined autoantibodies against human carbonic anhydrase II (ACA) and lactoferrin (ALF), antigens in the pancreatic duct cells and the pancreatic acinus, respectively, in 43 type 1 diabetic patients and 20 type 2 diabetic patients using the enzyme-linked immunosorbent assay method.

RESULTS

Of 43 type 1 diabetic patients, ACA was detected in 28 patients (65%) and ALF was detected in 29 patients (67%). One or both of the antibodies were detected in 33 type 1 diabetic patients (77%). In contrast, neither ACA nor ALF were detected in type 2 diabetic patients.

CONCLUSIONS

The high prevalence of both ACA and ALF strongly suggests the involvement of autoimmunity against the exocrine pancreas as well as the endocrine pancreas in some type 1 diabetic patients. We propose that these conditions be referred to as autoimmune exocrinopathy and endocrinopathy of the pancreas.

Autoimmune Pancreatitis Presenting as a Mass in the Head of the Pancreas: A Diagnosis to Differentiate from Cancer

We report a case of autoimmune pancreatitis presenting as a mass in the head of the pancreas that was successfully diagnosed without pancreaticoduodenectomy. The patient was a 64-year-old man who had no complaint. A routine physical checkup unexpectedly revealed mild diabetes and a low-echoic mass in the pancreatic head. The diagnosis was made by noting irregular narrowing of the main pancreatic duct, hypergammaglobulinemia, and increased immunoglobulin G levels. An open wedge biopsy of the mass was performed; this showed a marked fibrosis with lymphocyte- or macrophage-predominant inflammatory infiltrates. Immunohistochemical study revealed that the remnant acinar cells expressed Fas (CD95) ligand and not Fas. We review some of the literature and discuss various features and diagnostic clues of autoimmune pancreatitis. Awareness of this pathologic condition may prevent confusion with pancreatic malignancy and unnecessary surgery.

Lymphoplasmacytic chronic cholecystitis and biliary tract disease in patients with lymphoplasmacytic sclerosing pancreatitis

Lymphoplasmacytic sclerosing pancreatitis (LPSP) represents a distinctive form of chronic pancreatitis characterized by diffuse fibroinflammatory infiltrates that can involve both the pancreatic ducts and acinar parenchyma. Several cases of inflammatory infiltrates within the gallbladder have been reported in association with LPSP, but the spectrum of gallbladder pathology in patients with LPSP has not been systematically reviewed. Many patients with LPSP have distal CBD fibrosis, strictures, and inflammation, features that overlap somewhat with primary sclerosing cholangitis (PSC). In PSC, a pattern of gallbladder pathology termed "diffuse acalculous lymphoplasmacytic chronic cholecystitis" has been previously described as showing a triad of diffuse, mucosal-based, plasma cell-rich inflammatory infiltrates. We studied 20 gallbladders from patients with LPSP and compared them with 20 gallbladders in PSC, 20 gallbladders with chronic cholelithiasis, and 10 gallbladders from patients with benign (non-LPSP) pancreatic disease. The following features were evaluated: degree and composition of mucosal inflammation and deep (mural) inflammation, lymphoid nodules, metaplasia, dysplasia/neoplasia, fibrosis, muscular hypertrophy, Rokitansky-Aschoff sinuses, and cholesterolosis. The majority (60%) of gallbladders in LPSP contained moderate or marked inflammatory infiltrates and lymphoid nodules, frequencies similar to PSC but significantly higher than in chronic cholelithiasis and benign non-LPSP pancreatic disease. LPSP gallbladders received the highest scores for deep inflammation of all groups, and 35% of LPSP gallbladders showed transmural chronic cholecystitis. Overall, "diffuse lymphoplasmacytic chronic cholecystitis" was present in 50% of PSC cases and 25% of LPSP cases, but in only 5% of chronic cholelithiasis and none of non-LPSP benign pancreatic disease. Mucosal inflammation in LPSP gallbladders correlated significantly with the presence of inflammation in the extrapancreatic portion of the CBD. These findings suggest that inflammatory pathology of the gallbladder is frequently associated with LPSP and that it is part of the spectrum of biliary tract disease in these patients, rather than a simple reflection of the pancreatitis itself.

Eosinophilic pancreatitis and increased eosinophils in the pancreas

Prominent eosinophilic infiltrates are an unusual finding in the pancreas. Eosinophilic pancreatitis is one rare etiology of pancreatic eosinophilia, but other described causes of eosinophilic infiltrates have also included pancreatic allograft rejection, pancreatic pseudocyst, lymphoplasmacytic sclerosing pancreatitis (LPSP), inflammatory myofibroblastic tumor, and histiocytosis X. In this study we describe the clinicopathologic features of three new cases of eosinophilic pancreatitis and conduct a retrospective 18-year institutional review of the myriad disease processes associated with pancreatic eosinophilia. In the files of the Johns Hopkins Hospital, <1% of all pancreatic specimens had been noted to show increased numbers of eosinophils. Eosinophilic pancreatitis itself was a rare etiology for pancreatic eosinophilia, with only one in-house case over the 18-year study period and two additional referral cases. Other disease processes associated with prominent eosinophilic infiltrates were more common and included pancreatic allograft rejection (14 cases), LPSP (5 of 24 total LPSP cases evaluated), inflammatory myofibroblastic tumor (4 cases), and systemic mastocytosis (1 case). Patients with eosinophilic pancreatitis showed two distinct histologic patterns: 1) a diffuse periductal, acinar, and septal eosinophilic infiltrate with eosinophilic phlebitis and arteritis; and 2) localized intense eosinophilic infiltrates associated with pseudocyst formation. All three patients with eosinophilic pancreatitis had peripheral eosinophilia, and all had multiorgan involvement. One patient with LPSP also had marked peripheral eosinophilia, and 5 of 24 LPSP cases demonstrated prominent eosinophilic infiltrates in the gallbladder, biliary tree, and/or duodenum. Notably, not all of these patients with LPSP with prominent eosinophils in other organs had increased eosinophils in the pancreas itself. These results emphasize the infrequent nature of pancreatic eosinophilia and its multiple potential disease associations. True eosinophilic pancreatitis, although a fascinating clinicopathologic entity, is one of the rarest causes of pancreatic eosinophilia.

Pancreaticoduodenectomy (Whipple resections) in patients without malignancy: are they all 'chronic pancreatitis'?

Pancreaticoduodenectomy (Whipple resection) has evolved into a safe procedure in major high-volume medical centers for the treatment of pancreatic adenocarcinoma and refractory chronic pancreatitis. However, some Whipple resections performed for a clinical suspicion of malignancy reveal only benign disease on pathologic examination. We evaluated the frequency of such Whipple resections without tumor in a large series of pancreaticoduodenectomies and classified the diverse pancreatic and biliary tract diseases present in these specimens. Of 442 Whipple resections performed during 1999-2001, 47 (10.6%) were negative for neoplastic disease and, in 40 cases, had been performed for a clinical suspicion of malignancy. Most Whipple resections revealed benign pancreatic disease, including 8 (17%) alcohol-associated chronic pancreatitis, 4 (8.5%) gallstone-associated pancreatitis, 1 (2.1%) pancreas divisum, 6 (12.8%) "ordinary" chronic pancreatitis of unknown etiology, and 11 (23.4%) lymphoplasmacytic sclerosing pancreatitis. In particular, patients with lymphoplasmacytic sclerosing pancreatitis were all thought to harbor malignancy, whereas only 13 of 19 (68.4%) of Whipple resections showing histologically "ordinary" forms of chronic pancreatitis were performed for a clinical suspicion of malignancy. Benign biliary tract disease, including three cases of primary sclerosing cholangitis, two cases of choledocholithiasis-associated chronic biliary tract disease, and four fibroinflammatory strictures isolated to the intrapancreatic common bile duct, was a common etiology for clinically suspicious Whipple resections (22.5% of cases). Pancreatic intraepithelial neoplasia (PanIN) was a common finding among all pancreata, whether involved by pancreatitis or histologically normal. Overall, PanIN 1A/1B was present in 68.1%, PanIN 2 in 40.4%, and PanIN 3 in just 2.1%. These findings indicate that "benign but clinically suspicious" Whipple resections are relatively common in high-volume centers (9.2%) and reveal a diverse group of clinicopathologically distinctive pancreatic and biliary tract disease.

Autoimmune pancreatic disease: preparation of pancreatic juice for proteome analysis

The identification of pancreatic proteins is generally hampered by the high content and activity of proteases produced by this organ. The aim of this work was the development of a protocol for the analysis of pancreatic juice by two-dimensional (2-D) gel electrophoresis allowing consistent and reproducible protein analysis encompassed by high-resolution protein 2-D maps and subtle protein spot recognition without substantial losses due to proteases. Immobilized pH gradient (IPG) strips were used for the first dimension, the second dimension was performed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). However, the key step was the sample preparation technique. Improvements were achieved by using several protease inhibitors (phenylmethylsulfonyl fluoride, aprotinin, L-1-chloro-3-[4-tosyl-amido]-7-amino-2-heptanine (TLCK)-HCI, Complete) to prevent degradation of the proteins. The application of different pH-ranges was a valuable step for getting an overview of the expressed protein pattern. These investigations resulted in well-resolved 2-D maps with a high reproducibility.