Use of endoscopic ultrasound scoring to estimate the malignant potential of branch duct type intraductal papillary-mucinous neoplasms of the pancreas.

Abstract

182 Background: Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas are characterized by intraductal papillary epithelial growth, mucin hypersecretion, and cystic dilation of main or branch pancreatic ducts. However, it is still difficult to differentiate between benign and malignant, when it only involves the branch duct. The purpose of this study was to evaluate the role of endoscopic ultrasound (EUS) scoring in predicting malignancy in branch-duct type IPMNs, thus providing a convenient guideline to a clinician before considering surgical resection. Methods: We retrospectively reviewed all patients between Dec 1997 and April 2010 who underwent diagnostic and/or preoperative EUS for IPMNs. Borderline malignancy and invasive carcinoma were defined as a malignancy. Results: Of the 32 patients (mean age, 62 years), 13 male and 19 female were identified. Twelve people underwent operation, and there were 23 benign cases, and 9 malignant cases (borderline, n=6; invasive carcinoma, n=3). Among the six parameters (age, cyst size, mural nodule, associated main pancreatic duct dilation, patulous opening, thick septum) that have been known as important parameters for predicting malignancy in main duct type IPMNs, four were significant by Fisher's exact tests—namely, cyst size (p=.002), mural nodule (p =.003), associated main pancreatic duct dilation (p =.001), patulous opening (p =.05). In sizing the cysts, we scored 0 (cyst size ≤10 mm), 1 (11-20 mm), 2 (21-30 mm), 3 (>30 mm). In sizing the mural nodules, we scored 0 (no mural nodule), 1 (<5 mm), 2 (5-<10 mm), 3 (≥10 mm). For main pancreatic duct dilation, we scored 2, if there presented any associated main pancreatic duct dilation, and 0 if not. For the patulous opening, we scored 1 for present, 0 for not. Patients were dispersed from the highest score nine, to the lowest score zero. Mean score for benign cases was 2.47 (±1.59 SD), and 6.33 (±1.87 SD) for malignant cases (p =.001). Conclusions: We strongly recommend a radical surgery for patients scoring above 7(score 7, 8, 9), and a consideration of operation for scoring between 4 and 6, and careful follow up for scoring below 3. No significant financial relationships to disclose.