Autoimmune Pancreatitis with Massive Ascites and Multiple Pancreatic Cysts Successfully Treated with Prednisolone: A Case Report

A 64-year-old man with a history of diabetes and gallstones was admitted to our institution with suspected pancreatic malignancy. Computed tomography (CT) revealed multiple pancreatic cysts and massive ascites, and endoscopic ultrasonography (EUS) revealed a 28×27-mm hypoechoic mass in the pancreatic head. An EUS-guided fine-needle aspiration biopsy was performed, and there were no malignant findings. Based on the test results and imaging findings, type 1 autoimmune pancreatitis was suspected. The patient was administered 30 mg of prednisolone daily. After 11 days, CT revealed that the pancreatic cysts and ascites had reduced in size.

Amendment of the Japanese Consensus Guidelines for Autoimmune Pancreatitis, 2013 I. Concept and diagnosis of autoimmune pancreatitis

BACKGROUND

In response to the proposal of the international consensus diagnostic criteria (ICDC) for autoimmune pancreatitis (AIP) and the Japanese diagnostic criteria in 2011, the 2009 Japanese consensus guidelines for managing AIP required revision.

METHODS

Three committees [the professional committee for making clinical questions (CQs) and statements by Japanese specialists, the expert panelist committee for rating statements by the modified Delphi method, and the evaluating committee by moderators] were organized. Fifteen specialists for AIP extracted the specific clinical statements from 1,843 articles published between 1963 and 2012 (obtained from Pub Med and a secondary database, and developed the CQs and statements. The expert panel individually rated the clinical statements using a modified Delphi approach, in which a clinical statement receiving a median score greater than seven on a nine-point scale from the panel was regarded as valid.

RESULTS

The professional committee created 13 CQs and statements for the current concept and diagnosis of AIP, 6 for extra-pancreatic lesions, 6 for differential diagnosis, and 11 for treatment.

CONCLUSION

After evaluation by the moderators, amendments to the Japanese consensus guidelines for AIP have been proposed for 2013.

Autoimmune pancreatitis: an illustrated guide to diagnosis

Autoimmune pancreatitis (AIP) remains one of the rarer forms of pancreatitis but has become increasingly well recognized and widely diagnosed as it is an important differential, particularly due to the dramatic response to appropriate therapy. It is now best considered as part of a multisystem disease and the notion of "IgG4-related systemic sclerosing disease" has become widely recognized as the number of extra-pancreatic associations of AIP grows. More recently AIP has been classified into two subtypes: lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) with distinct geographical, age and sex distributions for the two subtypes, in addition to different pathological characteristics. The role of imaging is crucial in AIP and should be considered in conjunction with clinical, serological, and histopathological findings to make the diagnosis. Radiologists are uniquely placed to raise the possibility of AIP and aid the exclusion of significant differentials to allow the initiation of appropriate management and avoidance of unnecessary intervention. Radiological investigation may reveal a number of characteristic imaging findings in AIP but appearances can vary considerably and the focal form of AIP may appear as a pancreatic mass, imitating pancreatic carcinoma. This review will illustrate typical and atypical appearances of AIP on all imaging modes. Emphasis will be placed on the imaging features that are likely to prove useful in discriminating AIP from other causes prior to histopathological confirmation. In addition, examples of relevant differential diagnoses are discussed and illustrated.

Japanese consensus guidelines for management of autoimmune pancreatitis: I. Concept and diagnosis of autoimmune pancreatitis

As the number of patients with autoimmune pancreatitis (AIP) is increasing in Japan, practical guidelines for managing AIP need to be established. Three committees [the professional committee for developing clinical questions (CQs) and statements by Japanese specialists, the expert panelist committee for rating statements by the modified Delphi method, and the evaluating committee of moderators] were organized. Fifteen AIP specialists extracted specific clinical statements from a total of 871 articles in the literature using a PubMed search (1963-2008) and a secondary database, and developed the CQs and statements. The expert panelists individually rated these clinical statements using a modified Delphi approach in which a clinical statement receiving a median score greater than 7 on a 9-point scale from the panel was regarded as valid. The professional committee developed 13, 6, 6, and 11 CQs and statements for the concept and diagnosis, extra-pancreatic lesions, differential diagnosis and treatment, respectively. The expert panelists regarded them as valid after two-round modified Delphi approaches.After evaluation by the moderators, the Japanese clinical guidelines for AIP were established. The digest versions of the present guidelines have been published in the official journal of the Japan Pancreas Society, "Pancreas." Full versions divided into three series are scheduled to be published in the present and followings two issues in the Journal of Gastroenterology with approval of Professor Go VLW, the Editor-in-Chief of "Pancreas."

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.