Determination of Malignant and Invasive Predictors in Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Suggested Scoring Formula

Prediction of malignancy or invasiveness of branch duct type intraductal papillary mucinous neoplasm (Br-IPMN) is difficult, and proper treatment strategy has not been well established. The authors investigated the characteristics of Br-IPMN and explored its malignancy or invasiveness predicting factors to suggest a scoring formula for predicting pathologic results. From 1994 to 2008, 237 patients who were diagnosed as Br-IPMN at 11 tertiary referral centers in Korea were retrospectively reviewed. The patients' mean age was 63.1 +/- 9.2 yr. One hundred ninty-eight (83.5%) patients had nonmalignant IPMN (81 adenoma, 117 borderline atypia), and 39 (16.5%) had malignant IPMN (13 carcinoma in situ, 26 invasive carcinoma). Cyst size and mural nodule were malignancy determining factors by multivariate analysis. Elevated CEA, cyst size and mural nodule were factors determining invasiveness by multivariate analysis. Using the regression coefficient for significant predictors on multivariate analysis, we constructed a malignancy-predicting scoring formula: 22.4 (mural nodule [0 or 1]) + 0.5 (cyst size [mm]). In invasive IPMN, the formula was expressed as invasiveness-predicting score = 36.6 (mural nodule [0 or 1]) + 32.2 (elevated serum CEA [0 or 1]) + 0.6 (cyst size [mm]). Here we present a scoring formula for prediction of malignancy or invasiveness of Br-IPMN which can be used to determine a proper treatment strategy.

Determination of Malignancy Predictors in Branch Duct TypeIntraductal Papillary Mucinous Neoplasms of the Pancreas

PURPOSE: Branch duct type intraductal papillary mucinous neoplasms (Br-IPMN) have better prognosis and lower malignancy rate than do main duct type IPMNs (M-IPMN). However, surgical resection is necessary when malignancy is suspected, and radical resection should be performed in cases of invasive IPMN. The objectives of this study were to investigate the characteristics of Br-IPMN and related predictive malignancy/invasiveness factors and to present a standardized scoring system for predicting pathologic results. METHODS: We conducted a retrospective review of 91 patients diagnosed with Br-IPMNs between 1998 and 2007. Mean patient age was 62.5+/-9.0 years. Eighty (87.9%) patients had benign IPMNs (17 adenoma, 63 borderline malignancy), and 11 (12.1%) patients had malignant IPMNs (4 carcinoma in situ, 7 invasive carcinoma). Eighty-four (92.3%) patients had noninvasive IPMN, and 7 (7.7%) patients had invasive IPMN. RESULTS: The size of the cystic mass and the presence and size of the mural nodule were found by univariate analysis to be significantly different between the benign and malignant groups. History of DM, size of the cystic mass, size of the mural nodule, and thickness of the cystic wall were significantly different between the noninvasive and invasive IPMN groups on univariate analysis. The regression coefficients for the size of the cystic mass and for the size and presence of the mural nodule were calculated using multivariate analysis, and the scores predicting malignant and invasive IPMN determined (P=0.001, P=0.000, respectively). CONCLUSION: There are no universally held guidelines for surgical management of Br-IPMN patients. Hence, many clinicians have difficulty deciding the specific character of the resection they will pursue. By using malignancy- and invasiveness-predicting scores, we expect that much of this difficulty can be avoided in the future.

Surgical Management for Intraductal Papillary Mucinous Tumor (IPMT) of the Pancreas Confined to Branch Duct

PURPOSE: Intraductal papillary mucinous tumor (IPMT) of the branch duct type has been reported that it is associated with less aggressive histologic features than the main duct type. The purpose of this study was to evaluate the clinicopathologic features and the optimal management of branch duct type IPMT. METHODS: From October 1994 to November 2004, 30 cases who underwent operations with branch duct type IPMT were reviewed retrospectively. Clinicopathologic findings and late results of treatment were studied in 20 cases of the benign (adenoma, borderline malignancy) group and in 10 cases of the malignant (carcinoma in situ, invasive carcinoma) group. RESULTS: There were statistically significant difference in the 3 factors (mural nodule (P=0.030), diameter of the main pancreatic duct (P=0.036), main location of the tumor (P= 0.031)). There was no statistically significant difference in th survival analysis between the main duct type IPMT including combined type IPMT and the branch duct type IPMT (P=0.572), but there was significant difference between the benign group and the malignant group of the branch duct type IPMT (P=0.049). CONCLUSION: The long-term follow up result of the branch duct type IPMT is similar to that of the main and combined duct type IPMT. Therefore, it is not safe just to monitor the branch duct type IPMT. Our results suggest that surgery is certainly the gold standard treatment for the branch duct type IPMT. And after operation, close long term follow up with appropriate treatment is necessary due to tumor recurrence.