Endoscopic ultrasound-guided fine needle aspiration in the differentiation of type 1 and type 2 autoimmune pancreatitis

AIM:To investigate the usefulness of endoscopic ultrasound-guided fine needle aspiration(EUS-FNA) in the differentiation of autoimmune pancreatitis(AIP).METHODS:We retrospectively reviewed 47 of 56 AIP patients who underwent EUS-FNA and met the Asian diagnostic criteria.On 47 EUS-FNA specimens,we evaluated the presence of adequate material and characteristic features of lymphoplasmacytic sclerosing pancreatitis(LPSP) and idiopathic duct-centric pancreatitis(IDCP) mentioned in the International Consensus Diagnostic Criteria and examined if these findings make a contribution to the differential diagnosis of type 1 and type 2 AIP.A disposable 22-gauge needle was used for EUS-FNA.RESULTS:Adequate specimens including pancreatic tissue for differentiating AIP from cancer were obtained from 43 of 47 patients who underwent EUSFNA.EUS-FNA was performed from the pancreatic head in 21 cases,which is known to be technically difficult when performed by core biopsy;there was no significant difference in the results compared with pancreatic body-tail.Nine of 47 patients met level 1 findings of LPSP and 5 patients met level 2 findings of LPSP.No one met level 1 findings of IDCP,but 3 patients met level 2 findings of IDCP.Of 10 seronegative cases,2 cases were diagnosed with "definitive type 1 AIP",and 3 cases were diagnosed with "probable type 2 AIP" when considering both the level 2 histological findings and response to steroids.CONCLUSION:EUS-FNA is useful in the differentiation of type 1 and type 2 AIP,particularly in seronegative cases.

Use of color Doppler ultrasonography in the diagnosis of anomalous connection in pancreatobiliary disease

AIM: To estimate the detectability of anomalous connection in pancreatobiliary disease (ACPBD) cases, measuring gallbladder wall blood flow (GWBF).METHODS: In the retrospective study, we enrolled 42subjects with gallbladder wall thickening. GWBF velocity was determined as an average value of the peak velocity of color signals on the gallbladder wall, three times in each case. Based on the findings on endoscopic ultrasonography (EUS) or endoscopic retrograde cholangiopancreatography (ERCP), the 42 subjects were divided into 11 cases with ACPBD and 31 cases without ACPBD. In the prospective study, the subjects were 92 cases with gallbladder wall thickening. Using the cut-off level of the flow velocity obtained in the retrospective study, the usefulness of measuring GWBF velocity in diagnosing ACPBD was evaluated.RESULTS: In the retrospective study, imaging of GWBF was obtained in 40 of the 42 subjects. The mean GWBF velocity of the ACPBD cases was 29.4±3.9 cm/s(mean±SD), which was significantly different (P＜0.0001;95% CI 5.48-13.2) from that of the without ACPBD cases(20.1±5.9 cm/s). Based on this result, we prepared a receiver operating characteristic curve, and the cut-off level appropriate for diagnosing ACPBD was estimated to be 25 cm/s. In the prospective study, GWBF was detected in 86 of the 92 subjects. Based on the EUS or ERCP findings, the 92 subjects were divided into 15 cases with ACPBD and 77 cases without ACPBD. When a cut-off level of 25 cm/s was employed, ACPBD could be diagnosed with a sensitivity of 87.0% (13/15) and a specificity of87.3% (62/71).CONCLUSION: Measurement of GWBF velocity, which is less invasive and provides objective values, is very useful for diagnosing ACPBD prior to the development of malignant tumors in cases with gallbladder wall thickening.

Endoscopic papillectomy of minor papillar adenoma associated with pancreas divisum

Tumors of the minor papilla of the duodenum are quite rare.We successfully and safely treated an 18-mm adenoma of the minor papilla associated with pancreas divisum using endoscopic papillectomy.A 64-year-old man was admitted to our hospital for treatment of an asymptomatic mass in the minor papilla detected by upper gastrointestinal endoscopy.Endscopic analysis showed an 18-mm,whitish,sessile mass,located in the duodenum proximal to a normal-appearing major papilla.Endoscopic retrograde pancreatography did not reveal the pancreatic duct.Magnetic resonance cholangiopancreatography showed a lack of the ventral pancreatic duct.We suspected this case was associated with pancreatic divisum;therefore,we performed endoscopic papillectomy of the minor papilla tumor.Subsequently,endoscopic pancreatic stent placement in the minor papilla was done to prevent drainage disturbance.The patient has been asymptomatic without recurrence of tumor or stenosis of the Santorini orifice upon endoscopic examination for the past 2 years.

Clinical oncology for pancreatic and biliary cancers:Advances and current limitations

In the early 2000s,the main stream of endoscopic ultrasonography(EUS)changed from a mechanical scanning method to electronic radial or linear scanning methods.Subsequently,useful applications in trans-abdominal ultrasonography came within reach of EUS.In particular,contrast-enhanced EUS(CE-EUS)and EUS-elastography became cutting-edge diagnostic modalities for pancreatic disorders.Each type of pancreatic disorder has characteristic hemodynamics.CE-EUS uses color Doppler flow imaging and harmonic imaging to classify pancreatic lesions.EUS-elastography can assess tissue hardness by measuring its elasticity.This parameter appears to correlate with the malignant potential of the lesions.Tissue elasticity studies can provide information on both its pattern and distribution.The former is the conventional method of morphological diagnosis,but it is restricted to observations made in a region of interest(ROI).The latter is an unbiased analysis that can be performed by image analysis software and is theoretically constant,regardless of the ROI.Though EUSfine needle aspiration(FNA)is also a very useful diagnostic tool,there are several limitations.Diagnostic EUS-FNA of pancreatic cystic lesions has marginal utility mainly due to low sensitivity.Therefore,in particular,endoscopists should keep this limitation in mind.