review of literature on clinical pancreatology - The Pancreapedia

single-centre experience <strong>of</strong> BD-IPMNs. Some 190 patients with radiological imaging orhistological findings consistent with BD-IPMN were enrolled between 1998 and 2005. Thosewith less than 6 months' follow-up and no histological confirmation were excluded. BD-IPMNwas diagnosed by computed tomography and pancreatography in 105 patients andpathologically in 85. Eighteen patients had adenoma, 53 borderline malignancy, fivecarcinoma in situ and nine invasive carcinoma. Findings associated with malignancy werethe presence <strong>of</strong> radiologically suspicious features and a cyst size <strong>of</strong> at least 30 mm. Hadconsensus guidelines been applied, 54 patients would have undergone pancreatic resection,whereas only 28 <strong>of</strong> these patients actually had a resection; 12 <strong>of</strong> the latter patients had amalignancy compared with none <strong>of</strong> the 26 patients who were treated conservatively. It wasconcluded that a simple increase in cyst size is not a reliable predictor <strong>of</strong> malignancy.Observation is recommended for patients with a BD-IPMN smaller than 30 mm showing nosuspicious features on imaging [582].Intraductal papillary mucinous neoplasm (IPMN) was first described by Ohashi et al as"mucin-producing cancer" that affected the main pancreatic duct and produced excessivequantities <strong>of</strong> mucus, which filled and distended the ductal system. Prediction <strong>of</strong> malignancy<strong>of</strong> IPMN is important not only for indication <strong>of</strong> operation but for selection <strong>of</strong> operativeprocedure. International Consensus Guidelines recommended to resect all main duct andmixed variant IPMNs, and also recommended to resect branch duct IPMNs with symptoms.However, the criteria for resection in the branch duct IPMNs are still unclear. One studyaimed to determine the predictive factors for malignancy in IPMN, particularly cancerinvasion in IPMNs. It was <strong>review</strong>ed 26 cases with IPMN operated from 2003 to 2007. Amongthem, 21 cases were branched type, and the others were main duct type. It was measureddiameter <strong>of</strong> main pancreatic duct, cystic lesion size and intramural nodule size by endoscopicultrasonography or computed tomography and serum levels <strong>of</strong> CEA and CA19-9. As forfactors to predict malignancy only in branched type, the intramural nodules size and wassignificantly larger in the cases with cancer than that in the cases without cancer. Theanalysis all types IPMNs showed significant difference in the main duct diameter between 15benign and 11 malignant cases (5.5 + 4.0 mm vs 10.9 + 4.5 mm). Moreover, among the 11cases whose diameter <strong>of</strong> main pancreatic duct was less than 7 mm, no malignancy wasdetected. These results suggest that the diameter <strong>of</strong> main pancreatic duct as well asintramural nodules size is useful for prediction <strong>of</strong> malignancy and that minimally-invasivesurgery such as spleen-preserving distal pancreatectomy can be safely indicated for thecases whose diameter <strong>of</strong> main pancreatic duct is less than 7 mm [583].It was investigated preoperative findings that are useful to distinguish intraductal papillarymucinousneoplasm (IPMN) subtypes. One hundred twenty-three patients who underwentpancreatectomy for IPMN were analyzed clinicopathologically and radiologically. InvasiveIPM carcinomas (IPMCs) were subdivided into early-stage nonaggressive (minimally invasiveIPMC [MI-IPMC]) and more advanced and aggressive (invasive carcinoma originating inIPMC [IC-IPMC]) subtypes according to recently proposed pathological criteria. The lesionsconsisted <strong>of</strong> 27 IPMNs with low-grade dysplasia, 14 IPMNs with moderate dysplasia, 21IPMNs with high-grade dysplasia, 30 MI-IPMCs, and 31 IC-IPMCs. Multidetector-rowcomputed tomography detected a component <strong>of</strong> invasive carcinoma in IC-IPMC with 86percent sensitivity and 100 percent specificity. In patients with IPMNs other than IC-IPMC,multivariate analysis demonstrated 3 significant predictive factors <strong>of</strong> malignancy: IPMN size(>40 mm), IPMN duct type (main pancreatic duct or mixed type), and the presence <strong>of</strong> a muralnodule or thick septum. The diagnostic score obtained using these 3 factors showed a strongcorrelation with the presence <strong>of</strong> malignancy. It was concluded that regarded preoperativeevaluation <strong>of</strong> patients with IPMN, it is recommended to rule out IC-IPMC using multidetectorrowcomputed tomography and then to categorize IPMN other than IC-IPMC according tomalignant potential based on the diagnostic score [584].