Diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis(AIP) is a distinct form of chronic pancreatitis that is increasingly being reported. The presentation and clinical image findings of AIP sometimes resemble those of several pancreatic malignancies, but the therapeutic strategy differs appreciably. Therefore, accurate diagnosis is necessary for cases of AIP. To date, AIP is classified into two distinct subtypes from the viewpoints of etiology, serum markers, histology, other organ involvements, and frequency of relapse: type 1 is related to Ig G4(lymphoplasmacytic sclerosing pancreatitis) and type 2 is related to a granulocytic epithelial lesion(idiopathic duct-centric chronic pancreatitis). Both types of AIP are characterized by focal or diffuse pancreatic enlargement accompanied with a narrowing of the main pancreatic duct, and both show dramatic responses to corticosteroid. Unlike type 2, type 1 is characteristically associated with increasing levels of serum Ig G4 and positive serum autoantibodies, abundant infiltration of Ig G4-positive plasmacytes, frequent extrapancreatic lesions, and relapse. These findings have led several countries to propose diagnostic criteria for AIP, which consist of essentially similar diagnostic items; however, several differences exist for each country, mainly due to differences in the definition of AIP and the modalities used to diagnose this disease. An attempt to unite the diagnostic criteria worldwide was made with the publication in 2011 of the international consensus diagnostic criteria for AIP, established at the 2010 Congress of the International Association of Pancreatology(IAP).

Endoscopic ultrasonography guided-fine needle aspirationfor the diagnosis of solid pancreaticobiliary lesions:Clinicalaspects to improve the diagnosis

Endoscopic ultrasonography-guided fine-needle aspiration(EUS-FNA) has been applied to pancreaticobiliary lesions since the 1990 s and is in widespread use throughout the world today. We used this method to confirm the pathological evidence of the pancreaticobiliary lesions and to perform suitable therapies. Complications of EUS-FNA are quite rare, but some of them are severe. Operators should master conventional EUS observation and experience a minimum of 20-30 cases of supervised EUS-FNA on non-pancreatic and pancreatic lesions before attempting solo EUSFNA. Studies conducted on pancreaticobiliary EUSFNA have focused on selection of suitable instruments(e.g., needle selection) and sampling techniques(e.g., fanning method, suction level, with or without a stylet, optimum number of passes). Today, the diagnostic ability of EUS-FNA is still improving; the detection of pancreatic cancer(PC) currently has a sensitivity of 90%-95% and specificity of 95%-100%. In addition to PC, a variety of rare pancreatic tumors can be discriminated by conducting immunohistochemistry on the FNA materials. A flexible, large caliber needle has been used to obtain a large piece of tissue, which can provide sufficient histological information to be helpful in classifying benign pancreatic lesions. EUSFNA can supply high diagnostic yields even for biliary lesions or peri-pancreaticobiliary lymph nodes. This review focuses on the clinical aspects of EUS-FNA in the pancreaticobiliary field, with the aim of providing information that can enable more accurate and efficient diagnosis.

Endoscopic and biopsy diagnoses of superficial, nonampullary, duodenal adenocarcinomas

AIM: To investigate the accuracy of endoscopic or biopsy diagnoses of superficial nonampullary duodenal epithelial tumors(NADETs).METHODS:Clinicopathological data were reviewed for84 superficial NADETs from 74 patients who underwent surgery or endoscopic resection between September2002 and August 2014 at a single prefectural cancer center.Superficial NADETs were defined as lesions confined to the mucosa or submucosa.Demographic and clinicopathological data were retrieved from charts,endoscopic and pathologic reports.Endoscopic reports included endoscopic diagnosis,location,gross type,diameter,color,and presence or absence of biopsy.Endoscopic diagnoses were made by an endoscopist in charge of the examination before biopsy specimens were obtained.Endoscopic images were obtained using routine,front-view,high-resolution video endoscopy,and chromoendoscopy with indigocarmine was performed for all lesions.Endoscopic images were reviewed by at least two endoscopists to assess endoscopic findings indicative of carcinoma.Preoperative diagnoses based on endoscopy and biopsy findings were compared with histological diagnoses of resected specimens.Sensitivity,specificity,and accuracy were assessed for endoscopic diagnosis and biopsy diagnosis.RESULTS:The majority(81%)of the lesions were located in the second portion of the duodenum.The median lesion diameter was 14.5 mm according to final histology.Surgery was performed for 49 lesions from 39 patients,and 35 lesions from 35 patients were endoscopically resected.Final histology confirmed 65carcinomas,15 adenomas,and 3 hyperplasias.A finaldiagnosis of duodenal carcinoma was made for 91%(52/57)of the lesions diagnosed as carcinoma by endoscopy and 93%(42/45)of the lesions diagnosed as carcinoma by biopsy.The sensitivity,specificity,and accuracy of endoscopic diagnoses were 80%,72%,and 78%,respectively,whereas those of biopsy diagnoses were 72%,80%,and 74%,respectively.Preoperative diagnoses of carcinomas were made in88%(57/65)of the carcinoma lesions via endoscopy or biopsy.Endoscopic findings associated with carcinoma were red color,depression,and mixed-type morphology.CONCLUSION:Preoperative endoscopy and biopsy showed similar accuracies in the diagnosis of carcinoma in patients with superficial NADETs.