10 The association of malignancy with mural nodules on EUS was also reported in other studies.11,39 Yamao et al. reported that the combination of EUS and intraductal ultrasonography showed great accuracy in the diagnosis of invasive IPMN.12 Hara et al. showed that by intraductal ultrasound, 88% of lesions protruding 4 mm or more were malignant.13 Contrast-enhanced harmonic EUS is often used to examine the microvasculature and perfusion in the pancreas, and could prove to have a role in the diagnosis of malignant versus benign pancreatic cysts.14 Indeed, using contrast-enhanced EUS, Ohno et al. was able to classify

mural nodules of IPMN into four types. The diagnosis of IPMN with a type III or IV mural nodule had a sensitivity of 60%, specificity of DMXAA 92.9%, and accuracy of 75.9% for predicting malignancy.15 However, Song et al., in their study of 75 patients, showed that large mural nodules (≥ 10 mm) were observed in six (50%) of 12 patients with malignant IPMN versus three (30%) of 10 patients with benign IPMN, but the difference

was not statistically significant.32 In Korea, Kang et al. used cyst growth rate to predict malignancy of branch type IPMN. Cysts that grew more than 2 mm/year had a higher risk of malignancy (5-year risk of 45.5% vs 1.8%; P < 0.001).25 The latter is an interesting finding, and deserves further studies to provide corroborative evidence. Pancreatic cyst fluid viscosity, cytology, pancreatic

enzymes, and tumor markers could aid in the diagnosis of pancreatic cysts.40,41 The reported rate of correct diagnosis based on the cytology Selleckchem Selumetinib of cyst fluid by EUS-FNA varied from 54% to 97%, according to various reports.42–48 The specificity for the diagnosis of the presence of malignancy in mucinous cystic lesions ranged from 89% to 100%, and the sensitivity ranged from 22% to 100%.47–49 For patients with nodules, in addition to cytology, tissue diagnosis could be performed. Attempts had been made to improve the rate of correct diagnosis with brushing cytology for cysts50 and cystic wall biopsy.51 Of the pancreatic enzymes, amylase and lipase are the most well studied.52 As there is no clear standard for the cut-off learn more value for the diagnosis of mucinous cysts, a differential diagnosis based on a combination of values is necessary. In a pooled analysis of 450 patients, cyst fluid amylase concentration < 250 U/L virtually excluded pseudocysts.53 The American Society for Gastrointestinal Endoscopy guidelines stated that the measurement of cyst fluid amylase and lipase might provide clinically useful information about the cyst, but it could not provide a definitive diagnosis or determine the potential for malignancy.54 The most studied tumor markers are carcinoembryonic antigen (CEA) and CA19-9. The reported cut-off values varied significantly, and the data should not be applied without modification to the standards of various institutions.