The Japanese diagnostic criteria for autoimmune chronic pancreatitis: is it completely satisfactory?

Long-Term Survivors after Upfront Resection for Pancreatic Ductal Adenocarcinoma: An Actual 5-Year Analysis of Disease-Specific and Post-Recurrence Survival

BACKGROUND

Data on long-term actual survival in patients with surgically resected pancreatic ductal adenocarcinoma (PDAC) are limited. The aim of this study was to evaluate the actual 5-year disease-specific survival (DSS) and post-recurrence survival (PRS) in patients who underwent pancreatectomy for PDAC.

METHODS

Data from patients who underwent upfront surgical resection for PDAC between 2009 and 2014 were analyzed. Exclusion criteria included PDAC arising in the background of an intraductal papillary mucinous neoplasm and patients undergoing neoadjuvant therapy. All alive patients had a minimum follow-up of 60 months. Independent predictors of PRS, DSS, and survival > 5 years were searched.

RESULTS

Of the 176 patients included in this study, 48 (27%) were alive at 5 years, but only 20 (11%) had no recurrence. Median PRS was 12 months. In the 154 patients after disease recurrence, independent predictors of shorter PRS were total pancreatectomy, G3 tumors, early recurrence (< 12 months from surgery), and no treatment at recurrence. Median DSS was 36 months. Independent predictors of DSS were CA19-9 at diagnosis > 200 U/mL, total pancreatectomy, N + status, G3 tumors and perineural invasion. Only the absence of perineural invasion was a favorable independent predictor of survival > 5 years.

CONCLUSION

More than one-quarter of patients who underwent upfront surgery for PDAC were alive after 5 years, although only 11% of the initial cohort were cancer-free. Long-term survival can also be achieved in tumors with more favorable biology in an upfront setting followed by adjuvant chemotherapy.

Pancreatic duct "Icicle sign" on MRI for distinguishing autoimmune pancreatitis from pancreatic ductal adenocarcinoma in the proximal pancreas

OBJECTIVE

To determine reliable MRI features of autoimmune pancreatitis (AIP) in the proximal pancreas that could allow its differentiation from pancreatic ductal adenocarcinoma (PDAC).

METHODS

Twenty-three patients with AIP and 61 patients with PDAC in the proximal pancreas underwent MRI. Two observers analyzed MRI for lesion morphology, hypointensity degree on T1-weighted images, enhancement pattern during dynamic phases, capsule-like rim, presence of cysts and duct penetrating sign, morphology of bile duct, and icicle appearance and tortuosity of the upstream pancreatic duct. Sensitivity and specificity for the diagnosis of AIP were calculated for each category or combined.

RESULTS

When isointensity on the portal and late phase of MRI and/or the icicle sign of pancreatic duct are applied, 100 % sensitivity for the diagnosis of AIP in the proximal pancreas was achieved. Applying both mild T1 hypointensity similar to the spleen and the icicle sign enabled 100 % specificity for the diagnosis of AIP by differentiating it from PDAC.

CONCLUSION

The combination of the icicle sign in the upstream pancreatic duct and mild T1 hypointensity or isointensity on portal and late phase of dynamic MRI could be reliable MR features for the diagnosis of AIP in the proximal pancreas by allowing its differentiation from PDAC.

KEY POINTS

• The icicle sign of the pancreatic duct is useful for diagnosing AIP. • Mild T1 hypointensity similar to the spleen is useful for diagnosing AIP. • Isointensity on portal and late phases MRI is useful for diagnosing AIP.

Autoimmune pancreatitis: multidetector-row computed tomography (MDCT) and magnetic resonance (MR) findings in the Italian experience

Multidetector-row computed tomography (MDCT) and magnetic resonance (MR) imaging are currently the most frequently performed imaging modalities for the study of pancreatic disease. In cases of suspected autoimmune pancreatitis (AIP), a dynamic quadriphasic (precontrast, contrast-enhanced pancreatic, venous and late phases) study is recommended in both techniques. In the diffuse form of autoimmune pancreatitis (DAIP), the pancreatic parenchyma shows diffuse enlargement and appears, during the MDCT and MR contrast-enhanced pancreatic phase, diffusely hypodense and hypointense, respectively, compared to the spleen because of lymphoplasmacytic infiltration and pancreatic fibrosis. During the venous phase of MDCT and MR imaging, the parenchyma appears hyperdense and hyperintense, respectively, in comparison to the pancreatic phase. In the delayed phase of both imaging modalities, it shows retention of contrast media. A "capsule-like rim" may be recognised as a peripancreatic MDCT hyperdense and MR hypointense halo in the T2-weighted images, compared to the parenchyma. DAIP must be differentiated from non-necrotizing acute pancreatitis (NNAP) and lymphoma since both diseases show diffuse enlargement of the pancreatic parenchyma. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT has an important role. In the focal form of autoimmune pancreatitis (FAIP), the parenchyma shows segmental enlargement involving the head, the body-tail or the tail, with the same contrast pattern as the diffuse form on both modalities. FAIP needs to be differentiated from pancreatic adenocarcinoma to avoid unnecessary surgical procedures, since both diseases have similar clinical and imaging presentation. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT and MR imaging both have an important role. MR cholangiopancreatography helps in the differential diagnosis. Furthermore, MDCT and MR imaging can identify the extrapancreatic manifestations of AIP, most commonly biliary, renal and retroperitoneal. Finally, in all cases of uncertain diagnosis, MDCT and/or MR follow-up after short-term treatment (2-3 weeks) with high-dose steroids can identify a significant reduction in size of the pancreatic parenchyma and, in FAIP, normalisation of the calibre of the upstream main pancreatic duct.

Autoimmune pancreatitis: role of endoscopy in diagnosis and treatment

This review addresses the role of endoscopy in the diagnosis and treatment of autoimmune pancreatitis (AIP) and provides a diagnostic process for patients with suspected AIP. When should AIP be suspected? When can it be diagnosed without endoscopic examination? Which endoscopic approaches are appropriate in suspected AIP, and when? What are the roles of diagnostic endoscopic retrograde pancreatography, endoscopic biopsies, and IgG4 immunostaining? What is the proper use of the steroid trial in the diagnosis of AIP in patients with indeterminate computed tomography imaging? Should biliary stenting be performed in patients with AIP with obstructive jaundice?

Autoimmune pancreatitis and non-necrotizing acute pancreatitis: computed tomography pattern

OBJECTIVES

To retrospectively differentiate diffuse autoimmune pancreatitis from non-necrotizing acute pancreatitis at clinical onset with multi detector row computed tomography.

METHODS

36 Patients suffering from diffuse autoimmune pancreatitis (14) or non-necrotizing acute pancreatitis (22) were enrolled. Qualitative analysis included stranding, retroperitoneal fluid film, capsule-like rim enhancement and pleural effusion. In quantitative analysis pancreatic density was measured in all phases. The vascularization behaviour was assessed using the relative enhancement rate across all phases.

RESULTS

Pancreatic density resulted lower in non-necrotizing acute pancreatitis compared to diffuse autoimmune pancreatitis patients in pre-contrast phase and higher in pancreatic phase. Relative enhancement rate evaluation confirmed different vascularization behaviours of the two diseases. Only non-necrotizing acute pancreatitis Patients presented peripancreatic stranding and fluid in the retromesenteric interfascial plane.

CONCLUSIONS

Multi detector row computed tomography is a useful technique for differentiating diffuse autoimmune pancreatitis from non-necrotizing acute pancreatitis at clinical onset. Peripancreatic stranding and retroperitoneal fluid film, characteristic of non-necrotizing acute pancreatitis, and late-phase peripheral rim enhancement, characteristic of diffuse autoimmune pancreatitis, provide qualitative clues to the differentiation. A quantitative study of contrast enhancement patterns, considering the relative enhancement rate, can assist in the differential diagnoses of two diseases.

Spontaneous regression of pancreatic cancer: Real or a misdiagnosis?

Spontaneous tumor regression has been subject of numerous studies and speculations for many years. This phenomenon is exceptional, but well reported, in some types of tumors, but not in pancreatic cancer. Pancreatic cancer has the worst five-year survival rate of any cancer. Despite numerous molecular studies and clinical approaches, using several mouse models, this cancer responds poorly to the existing chemotherapeutic agents and progress on treatment remains elusive. Although pancreatic cancer tumors seldom undergo spontaneous regression, and some authors take that with skepticism, there are some cases reported in the literature. However, the variability in the description of the reports and technical details could make this process susceptible to misdiagnosis. Distinguishing between different types of pancreatic carcinoma should be taken with caution as they have wide differences in malignant potential. Diseases such as pancreatic benign tumors, insulinomas, or autoimmune pancreatitis could be responsible for this misdiagnosis as a pancreatic cancer. Here we review different cases reported, their clinical characteristics, and possible mechanisms leading to spontaneous regression of pancreatic cancer. We also discuss the possibilities of misdiagnosis.

Autoimmune pancreatitis versus pancreatic cancer: a comprehensive review with emphasis on differential diagnosis

BACKGROUND

Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis with a discrete pathophysiology, occasional diagnostic radiological findings, and characteristic histological features. Its etiology and pathogenesis are still under investigation, especially during the last decade. Another aspect of interest is the attempt to establish specific criteria for the differential diagnosis between autoimmune pancreatitis and pancreatic cancer, entities that are frequently indistinguishable.

DATA SOURCES

An extensive search of the PubMed database was performed with emphasis on articles about the differential diagnosis between autoimmune pancreatitis and pancreatic cancer up to the present.

RESULTS

The most interesting outcome of recent research is the theory that autoimmune pancreatitis and its various extra-pancreatic manifestations represent a systemic fibro-inflammatory process called IgG4-related systemic disease. The diagnostic criteria proposed by the Japanese Pancreatic Society, the more expanded HISORt criteria, the new definitions of histological types, and the new guidelines of the International Association of Pancreatology help to establish the diagnosis of the disease types.

CONCLUSION

The valuable help of the proposed criteria for the differential diagnosis between autoimmune pancreatitis and pancreatic cancer may lead to avoidance of pointless surgical treatments and increased patient morbidity.

Characteristics of autoimmune pancreatitis based on serum IgG4 level

BACKGROUND

Autoimmune pancreatitis is categorized as an IgG4-related autoimmune disease, mostly associated with serological alterations, however characteristics of autoimmune pancreatitis based on serum markers have not been fully evaluated.

METHODS

We evaluated demographics, symptoms, imaging and therapeutic outcome in 27 cases of autoimmune pancreatitis stratified by serum IgG4 level.

RESULTS

Twenty patients (74%) had elevated serum IgG4 and 7 (26%) had normal IgG4 levels. Compared to patients with normal serum IgG4 levels, patients with elevated IgG4 had higher incidence of jaundice at onset (14.3% vs. 80%, respectively; P=0.002), more frequent diffuse pancreatic enlargement at imaging (14.3% vs. 60%, respectively; P=0.04), significantly higher 18F-2-fluoro-2-deoxy-d-glucose uptake of pancreatic lesions (SUV max: 4.0 vs. 5.7, respectively; P=0.02), more frequent extrapancreatic lesions (42.9% vs. 85%, respectively; P=0.03). Response to steroids was recognized regardless of serum IgG4 level, however maintenance therapy was required more frequently amongst patients with elevated compared to normal IgG4 (85.7% vs. 33.3%, respectively; P=0.04).

CONCLUSIONS

Clinical features of autoimmune pancreatitis are different based on level of serum IgG4. Further studies are needed to clarify if normal serum IgG4 cases are a precursor of active type 1 or type 2 autoimmune pancreatitis.

[Clinical characteristics of autoimmune pancreatitis]

Korean autoimmune pancreatitis (AIP) criteria 2007 was aimed to diagnose the wide spectrum of AIP with high sensitivity. The most crucial issue when caring for patients with suspected AIP is to differentiate AIP from pancreatic cancer. Pancreatic cancer can be distinguished from AIP by pancreatic imaging, measurement of serum IgG4 levels, endoscopic ultrasound guided fine needle aspiration and trucut biopsy, and steroid trial. Autoimmune pancreatitis is a rare systemic fibroinflammatory disease which can affect not only the pancreas, but also a variety of organs such as the bile ducts, salivary glands, retroperitoneum, and lymph nodes. Organs affected by AIP have a lymphoplasmacytic infiltrate rich in IgG4-positive cells. This inflammatory process responds dramatically to oral steroid therapy. Granulocytic epithelial lesion (GEL) positive AIP patients differ from GEL negative AIP patients in clinical features such as equal gender ratio, younger mean age, no increase in serum IgG4, no association with extrapancreatic involvement, no relapse, and frequent association with inflammatory bowel disease. Further investigation is needed to clarify the pathogenic mechanisms including more definite serological markers for theses two entities.

A practical approach to the diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis is a disease characterized by specific pathological features, different from those of other forms of pancreatitis, that responds dramatically to steroid therapy. The pancreatic parenchyma may be diffusely or focally involved with the possibility of a low-density mass being present at imaging, mimicking pancreatic cancer. Clinically, the most relevant problems lie in the diagnosis of autoimmune pancreatitis and in distinguishing autoimmune pancreatitis from pancreatic cancer. Since in the presence of a pancreatic mass the probability of tumour is much higher than that of pancreatitis, the physician should be aware that in focal autoimmune pancreatitis the first step before using steroids is to exclude pancreatic adenocarcinoma. In this review, we briefly analyse the strategies to be followed for a correct diagnosis of autoimmune pancreatitis.

The revised Japanese clinical diagnostic criteria for chronic pancreatitis

In Japan, we are now using the clinical diagnostic criteria for chronic pancreatitis (CP) that were revised in 2001 to add the findings of magnetic resonance cholangiopancreatography to the criteria compiled by the Japan Pancreas Society (JPS) in 1995. Because the current criteria are set for diagnosing advanced CP, they are unlikely to improve patients' prognoses. In addition, they seem unsuitable for current clinical practice because exocrine pancreatic function tests, which have become obsolete in Japan, are included in the diagnostic factors. For these reasons, the Research Committee on Intractable Pancreatic Diseases supported by the Ministry of Health, Labour and Welfare of Japan, the JPS and the Japanese Society of Gastroenterology have revised the criteria. The revised criteria are unique in that they contain an introduction to the concept of early CP. It is a challenge aimed at improvement of the long-term prognosis of CP patients by early diagnosis and therapeutic intervention in this disease. We need to determine and clarify the clinico-pathological outcome of early CP by a prospective long-term follow-up of the patients in this category.

Autoimmune pancreatitis

Autoimmune pancreatitis is becoming a more widely recognized form of pancreatitis that can mimic pancreatic or biliary malignancy. The combination of serological, histological and radiographic findings makes it unique among pancreatic diseases. The presence of autoantibodies, IgG4 and a lymphoplasmacytic infiltrate reflect its autoimmune etiology. The dramatic response to steroids is also a distinguishing feature and differentiates it from other pancreatic diseases.

Autoimmune pancreatitis in Japan: overview and perspective

Since the rediscovery and definition of autoimmune pancreatitis (AIP) by Yoshida et al. in 1995, the disease has been attracting attention because of its unique clinical features and practical issues. This disease shows very impressive imaging findings, serological changes, and characteristic histopathology. It occurs most commonly in elderly males with painless jaundice or mild abdominal pain; resemblance in imaging findings between AIP and pancreatobiliary cancers poses an important practical issue of differentiation. With increasing recognition of AIP and accumulation of cases, another important feature of this disease has been revealed, i.e., association of extrapancreatic organ involvements. Initially misunderstood because it can be accompanied by other autoimmune disorders, such as Sjögren's syndrome or primary sclerosing cholangitis (PSC), AIP is now known to be associated with unique types of sialadenitis and cholangitis distinct from Sjögren's syndrome or PSC. Now the concept of "IgG4-related sclerosing disease" has become widely accepted and the list of organs involved continues to increase. With worldwide recognition, an emerging issue is the clinical definition of other possible types of autoimmune-related pancreatitis called "idiopathic duct-centric chronic pancreatitis (IDCP)" and "AIP with granulocyte epithelial lesion (GEL)" and their relation to AIP with lymphoplasmacytic sclerosing pancreatitis (LPSP). The time has arrived to establish clinical diagnostic criteria of AIP based on international consensus and to discuss regional and racial differences in the clinicopathological features of AIP. Consensus guidelines are also required for the ideal use of steroids in the treatment of AIP to suppress recurrence efficiently with minimal side effects. There are many issues to be settled in AIP; international collaboration of experts in the pancreas field is necessary to clarify the entire picture of this unique and important disease.

Misdiagnosis of autoimmune pancreatitis: a caution to clinicians

Autoimmune pancreatitis (AIP) is a chronic inflammatory disease of the pancreas that is increasingly encountered worldwide. It has generated considerable interest, in part because the inflammatory process usually responds dramatically to corticosteroid therapy. The most common presentation mimics that of pancreatic cancer; thus, a correct diagnosis of AIP can avoid major surgery. However, the diagnosis is challenging, because its incidence is far lower than that of the diseases it mimics and there is no single diagnostic clinical feature or test that can identify the full spectrum of AIP. Therefore, we are increasingly encountering patients misdiagnosed as having AIP. The misdiagnosis typically occurs in three scenarios: (i) treatment of pancreatic or biliary malignancy with corticosteroids and/or immunomodulators, (ii) treatment of chronic abdominal pain with corticosteroids and/or immunomodulators, or (iii) performance of operative resection for autoimmune disease. Our purpose is to highlight this growing clinical problem and to reinforce the use of published guidelines for the diagnosis and management of AIP.

Eosinophilia associated with chronic pancreatitis

OBJECTIVES

Eosinophilia (>0.5 x 10/L eosinophils [EOSs] in the peripheral blood) has been overlooked in the study of chronic pancreatitis (CP). The purpose of this study was to investigate the clinical significance and causes of eosinophilia by analyzing the features of CP cases with eosinophilia.

METHODS

We retrospectively analyzed the clinical features of CP patients with eosinophilia and compared them with CP patients without eosinophilia.

RESULTS

There were 28 cases (15.6%) of CP with eosinophilia among 180 CP patients. The ratio of male to female patients was 8.3:1. The mean patient age at the time of diagnosis was 49.0 (+/- 16.2) years. The peak value of EOSs in the patients' peripheral blood was 0.935 (+/- 0.600) x 10/L. The incidence of eosinophilia in autoimmune pancreatitis was significantly higher than in non-autoimmune pancreatitis CP cases. The incidence of pancreatic ascites, pancreatic enlargement, or jaundice in CP cases with eosinophilia was significantly higher than in those without eosinophilia. There was no obvious infiltration of EOSs in the pancreatic tissues of 16 pathology or cytology specimens.

CONCLUSIONS

The occurrence of eosinophilia during the course of CP is not unusual. This may be related to autoimmune mechanisms, serous membrane response, or the progression of pancreatic inflammation and fibrosis.

Asian diagnostic criteria for autoimmune pancreatitis: consensus of the Japan-Korea Symposium on Autoimmune Pancreatitis

In 2002, the Japan Pancreas Society (JPS) was the first in the world to propose diagnostic criteria for autoimmune pancreatitis (AIP). Since the concept of AIP has changed with the accumulation of AIP cases, the Research Committee of Intractable Pancreatic Diseases (RCIPD) provided by the Ministry of Health, Labour and Welfare of Japan and the JPS issued revised clinical diagnostic criteria of AIP in 2006. The Asan Medical Center of Korea also proposed diagnostic criteria for AIP in 2006. However, there are subtle but clinically challenging differences between the Japanese and Korean criteria. This inconsistency makes it difficult to compare data in studies from different centers and elucidate the characteristics of AIP. To reach a consensus on AIP, the RCIPD and the Korean Society of Pancreatobiliary Diseases established the following Asian criteria for the diagnosis of AIP: I-1. Imaging studies of pancreatic parenchyma show a diffuse/segmental/focally enlarged gland, occasionally with a mass and/or a hypoattenuation rim. I-2. Imaging studies of pancreaticobiliary ducts show diffuse/segmental/focal pancreatic ductal narrowing, often with stenosis of the bile duct. (Both I-1 and I-2 are required for diagnosis). II. Elevated level of serum IgG or IgG4, and detection of autoantibodies. III. Common lymphoplasmacytic infiltration and fibrosis, with abundant IgG4-positive cell infiltration. AIP should be diagnosed when criterion I and one of the other two criteria are satisfied, or when histology shows the presence of lymphoplasmacytic sclerosing pancreatitis in the resected pancreas. A diagnostic trial of steroid therapy can be applied carefully by expert pancreatologists only in patients fulfilling criterion I alone with negative diagnostic work-up results for pancreatobiliary cancer.

Autoimmune pancreatitis

Autoimmune pancreatitis is the pancreatic manifestation of a systemic disorder that affects various organs, including the bile duct, retroperitoneum, kidney, and parotid and lacrimal glands. It represents a recently described subset of chronic pancreatitis that is immune mediated and has unique histologic, morphologic, and clinical characteristics. A hallmark of the disease is its rapid response to corticosteroid treatment. Although still a rare disease, autoimmune pancreatitis is increasingly becoming recognized clinically, leading to evolution in the understanding of its prognosis, clinical characteristics, and treatment.

Current diagnosis and management of unusual pancreatic tumors

BACKGROUND

The finding of a solid or cystic mass in the pancreas is becoming more common secondary to the increasing use of cross-sectional imaging and the improved sensitivity of such studies for the detection of pancreatic abnormalities. Because of the aggressive natural history of pancreatic cancer, this has caused concern that all pancreatic abnormalities may be cancer as well as confusion over proper diagnostic and treatment algorithms. This review provides an overview of the natural history, diagnostic considerations, and treatment recommendations for the less common tumors of the pancreas which can be misinterpreted as pancreatic cancer including: solid pseudopapillary tumors (SPT), acinar cell carcinoma (ACC), lymphoplasmacytic sclerosing pancreatitis (LPSP), primary pancreatic lymphoma (PPL), and metastatic renal cell carcinoma to the pancreas.

DATA SOURCES

A Medline search was conducted to identify studies investigating the clinicopathologic features, molecular genetics, pathogenesis, diagnosis, and treatment of SPT, ACC, LPSP, PPL, and pancreatic metastases.

CONCLUSIONS

It is often possible to obtain an accurate pretreatment diagnosis for these unusual pancreatic tumors and to successfully differentiate them from the more common pancreatic malignancies.

Diagnosis and management of autoimmune pancreatitis: Experience from China

AIM: To determine the clinical, radiographic and pathologic characteristics, diagnostic and treatment modalities in patients with autoimmune pancreatitis (AIP).

METHODS: In this retrospective study, the data of patients with diagnosed chronic pancreatitis (CP) between 1995 and 2006 in Chinese PLA General Hospital were included to screen for the cases with AIP, according to the following diagnostic criteria: (1) diagnostic histopathologic features, and abound IgG4-positive plasma cells on pancreatic tissues; (2) characteristic imaging on computed tomography and pancreatography, together with increased serum IgG, γ-globulin levels or presence of autoantibodies; (3) response to steroid therapy. The clinical, radiographic and pathologic characteristics, diagnostic and treatment modalities, and outcome of AIP cases were reviewed.

RESULTS: Twenty-five (22 male, 3 female; mean age 54 years, 36-76 years) out of 510 CP patients were diagnosed as AIP, which accounted for 49% (21/43) of CP population undergoing surgical treatment in the same period. The main clinical manifestations included intermittent or progressive jaundice in 18 cases (72%), abdominal pain in 11 (44%), weight loss in 10 (40%), and 3 cases had no symptoms. The imaging features consisted of pancreatic enlargement, especially in the head of pancreas (18 cases), strictures of main pancreatic duct and intrapancreatic bile duct. Massive lymphocytes and plasma cells infiltration in pancreatic tissues were showed on pathology, as well as parenchymal fibrosis. Twenty-three patients were misdiagnosed as pancreaticobiliary malignancy, and 21 patients underwent exploratory laparotomy, the remaining 4 patients dramatically responded to steroid therapy. No pancreatic cancer occurred during a mean 46-mo follow-up period.

CONCLUSION: AIP patients always are subjected to mistaken diagnosis of pancreatic cancer and an unnecessary surgical exploration, due to its similarity in clinical features with pancreatic cancer. The differential diagnosis with high index of suspicion of AIP would improve the diagnostic accuracy for AIP.

Autoimmune chronic pancreatitis

BACKGROUND

Autoimmune pancreatitis (AIP) is a unique form of chronic pancreatitis that is characterized by swelling of the pancreas, narrowing of the main pancreatic duct (MPD), elevation of serum gamma globulin, or immunoglobulin G or presence of autoantibody, lymphoplasmacytic infiltration and dense fibrosis on histopathology. It is responsive to steroid therapy. The incidence of AIP can reach 5-6% of chronic pancreatitis. It can present as obstructive jaundice, body weight loss, and pancreas head mass mimicking pancreatic cancer. The recognition of AIP can avoid major surgery such as pancreatic resection.

METHODS

From May 2003 to July 2007, a total of 5 cases of AIP were reviewed retrospectively. The diagnosis was made on imaging study, serology, steroid response and/or histology if surgery was carried out.

RESULTS

There were 2 male and 3 female patients, with a mean age of 61 (39-75) years. Atypical AIP was found in the first case and typical AIP in the remaining 4. The presenting clinical pictures were mild epigastric pain, obstructive jaundice, and loss of body weight in 4 cases, with associated autoimmune disease in 1. Diffuse or long segmental enlargement of the pancreas without peripancreatic fat infiltration was found in all patients except 1 who only had focal pancreatic head enlargement. Distal common bile duct (CBD) stricture was seen in 4 cases and the median CBD stricture length was 1.2 (0.5-2.5) cm. Multiple narrowing of the whole MPD was seen in 2 cases, focal narrowing of the MPD in 2 and long segmental narrowing of the MPD in 1. Serum immunoglobulin G tests were done in 4 cases and were elevated in all. Antinuclear antibody was positive in 3. The first case was operated on after a preoperative diagnosis of suspicious pancreatic head tumor. The subsequent 3 cases were diagnosed correctly as AIP. The last case presented with distal CBD stricture and hypoechoic lesion in the pancreas head on endoscopic ultrasound, with only borderline pancreatic enlargement on computed tomography, and he was operated on. Retrospective endoscopic retrograde pancreatogram review revealed MPD narrowing in the pancreatic body. Endoscopic retrograde brush cytology was performed and was negative for malignancy in 3 cases. Steroid therapy was given in 3 and was responsive, but there were 2 recurrences.

CONCLUSION

AIP should be a differential diagnosis in distal CBD stricture and pancreatic head mass when the patient has: (1) diffuse or long segmental enlargement of the pancreas without peripancreatic fat infiltration, with multiple narrowing of the MPD without much upstream dilatation, or narrowing of the MPD not corresponding to the region of CBD stricture; and (2) abnormal immunoserologic tests.

Chronic pancreatitis

PURPOSE OF REVIEW

As in previous reviews in this journal, this review is focused on the most important new observations in chronic pancreatitis made in the past year and the beginning of this year.

RECENT FINDINGS

Important observations include the following: first, the natural history and course of chronic pancreatitis; second, that smoking enhances the risk of chronic pancreatitis; third, possible new function tests in combination with imaging procedures; fourth, the superiority of surgery compared with endotherapy for long-term pain relief; fifth, new insights in autoimmune pancreatitis.

SUMMARY

All in all, little progress has recently been made in the field of diagnosis and therapy of chronic pancreatitis. There are some studies in the field of endotherapy and autoimmune pancreatitis that are promising however.

The sensitivity and specificity of serum immunoglobulin G and immunoglobulin G4 levels in the diagnosis of autoimmune chronic pancreatitis: Korean experience

OBJECTIVES

Serum immunoglobulin G (IgG) and/or IgG4 elevation is one of the notable characteristics of autoimmune chronic pancreatitis (AIP). The purpose of this study was to compare the sensitivity and specificity of IgG with those of IgG4 in the diagnosis of AIP.

METHODS

From December 2005 to March 2006, patients who were diagnosed as having ordinary chronic pancreatitis of a certain cause (n = 67) and pancreatic cancer (n = 76) in Asan Medical Center were enrolled. The IgG and IgG4 levels of these patients were compared with those of 35 AIP patients diagnosed in Asan Medical Center.

RESULTS

The percentage of patients with serum IgG level more than 1800 mg/dL was 10.4% (7/67), 2.6% (2/76), and 54.3% (19/35) in patients with ordinary chronic pancreatitis, pancreatic cancer, and AIP, respectively. As for serum IgG4 levels more than 135 mg/dL, it was 11.9% (8/67), 1.3% (1/76), and 73.3% (22/30), respectively. The specificity of IgG at 1800 mg/dL and IgG4 at 135 mg/dL was both 93.7%. The serum IgG4 showed high specificity (98.7%) in differentiating AIP from pancreatic cancer. The IgG4 level at 141 mg/dL was determined as the most optimal cutoff value with resulting sensitivity and specificity of 73.3% and 95.1%, respectively (area under the curve, 0.816), whereas for IgG, it was determined as 1770 mg/dL, with sensitivity and specificity of 57.1% and 93.7% (area under the curve, 0.788).

CONCLUSIONS

The sensitivity of serum IgG4 tended to be higher than that of IgG in the diagnosis of AIP. The IgG4 showed high specificity in the differential diagnosis of AIP from pancreatic cancer. Serum IgG4 should be included in the diagnostic workup for AIP.

Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound for diagnosis of chronic pancreatitis

The diagnosis of chronic pancreatitis is based on altered pancreatic morphology and function. A spectrum of disease exists, and milder forms of disease may be missed by CT but demonstrated by endoscopic retrograde cholangiopancreatography (ERCP) or endoscopic ultrasound (EUS). The accuracy of ERCP and EUS for diagnosis of "minimal change" or "early" chronic pancreatitis is controversial, particularly when the results from these imaging procedures are discordant with each other or with tests of pancreatic function; in some cases ERCP and EUS should be considered indeterminate for diagnosis. This review discusses recent data concerning the accuracy of ERCP and EUS for diagnosis of chronic pancreatitis, the use of EUS fine-needle aspiration for differential diagnosis of pancreatic masses, and the use of EUS and EUS-guided TruCut biopsy for diagnosis of autoimmune pancreatitis.

Autoimmune pancreatitis

Autoimmune pancreatitis is a rare systemic fibrotic inflammatory disorder that can affect organs such as the bile ducts, salivary glands, and retroperitoneal lymph nodes, in addition to the pancreas. Morphological characteristics of autoimmune pancreatitis include a diffusely enlarged 'sausage-shaped' pancreas and an irregularly narrowed duct of Wirsung. According to the revised Japan Pancreas Society criteria, the diagnosis of autoimmune pancreatitis requires that one or more secondary serologic or histologic criteria are also met: the presence of autoantibodies, elevated levels of gamma-globulins, IgG or IgG(4), a lymphoplasmacytic infiltrate, or pancreatic fibrosis. The presence in any affected organ of a lymphoplasmacytic inflammatory infiltrate containing greater than 10 IgG(4)-positive cells per high-power field is pathognomonic for autoimmune pancreatitis. Precise data on the incidence and prevalence of autoimmune pancreatitis are currently not available because most reports involve either limited patient series or resection specimen cohorts. New diagnostic tools and further studies of the underlying pathophysiology and prognosis of autoimmune pancreatitis are needed for adequate and effective treatment strategies to be developed. The most crucial issue when caring for patients with suspected autoimmune pancreatitis is to differentiate autoimmune pancreatitis from pancreatic carcinoma, because pancreatic carcinoma requires surgery, whereas autoimmune pancreatitis responds well to steroid treatment.

Autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a benign, IgG4-related, fibroinflammatory form of chronic pancreatitis that can mimic pancreatic ductal adenocarcinoma both clinically and radiographically. Laboratory studies typically demonstrate elevated serum IgG4 levels and imaging studies reveal a diffusely or focally enlarged pancreas with associated diffuse or focal narrowing of the pancreatic duct. The pathologic features include periductal lymphoplasmacytic inflammation, obliterative phlebitis, and abundant IgG4-positive plasma cells. The treatment of choice for AIP is steroid therapy. Diagnostic criteria for AIP have been proposed that incorporate histologic, radiographic, serologic, and clinical information.

Autoimmune pancreatitis: a message from Japan

Autoimmune pancreatitis (AIP) is a unique form of chronic pancreatitis generally observed in aged people and characterized by the presence of autoantibodies,(1-3) elevated levels of immunoglobulins,(4) enlargement of the pancreas (diffuse or focal) on ultrasonography (US) or computed tomography (CT),(1-3,5) diffuse narrowing of the main pancreatic duct (MPD) with an irregular wall,(1,3,5-8) and pathologic features of dense lymphoplasmacytic inflammation and fibrosis, as well as a favorable response to steroid therapy.(1-3,5,8) The clinical findings in AIP include obstructive jaundice secondary to biliary stenosis, mild epigastralgia, and diabetes mellitus. The clinical, laboratory, and radiological features respond promptly to oral steroid therapy.(1-3,5,6,8) Although prompt response to oral steroid therapy may be helpful in the differential diagnosis of AIP, careful imaging studies are necessary to exclude cancer of the pancreas or common bile duct (CBD).

Diagnostic criteria for autoimmune chronic pancreatitis

Autoimmune chronic pancreatitis (AIP) is a clinically attractive entity because of its dramatic response to oral steroid therapy. Recently, as awareness of AIP is increasing, more cases are being reported. However, there are still no established worldwide diagnostic criteria for AIP. Since the Japan Pancreas Society (JPS) published diagnostic criteria for autoimmune chronic pancreatitis in the year 2002, increased attention toward this relatively new disease entity has enabled more cases of AIP to be correctly diagnosed. As previously unrecognized or misdiagnosed cases of autoimmune chronic pancreatitis are found, an increasing number of cases that are not in full accordance with the JPS diagnostic criteria are revealed. As a result, some groups have developed and cited their own criteria in the reporting of autoimmune chronic pancreatitis. The absence of consistent, uniform criteria has made comparison of different cases diagnosed under various guidelines difficult. In this review, we discuss and compare the four current sets of diagnostic criteria, focusing on their individual strengths and weaknesses.

The diagnostic criteria for autoimmune chronic pancreatitis: it is time to make a consensus

Autoimmune chronic pancreatitis (AIP) is increasingly being recognized as a worldwide entity. In 2002, the Japan Pancreas Society published diagnostic criteria for AIP. Since then, increased attention toward this relatively new disease entity has enabled more cases of AIP to be correctly diagnosed, allowing for proper management and avoidance of surgery. Retrospective inclusion of previously unrecognized or misdiagnosed cases of AIP has revealed an increasing number of cases that are not in full accordance with the Japanese diagnostic criteria. As a result, some groups have developed and cited their own criteria in the reporting of AIP, and the Japan Pancreas Society criteria have also undergone revision recently. The absence of consistent and uniform criteria has made the comparison of different cases diagnosed under various guidelines difficult. In this review, we discuss and compare the 4 current diagnostic criteria, focusing on their own strength and weakness with the aim of providing a framework for the development of unified criteria that represent an international consensus.