Natural courses of branch duct intraductal papillary mucinous neoplasm.

PURPOSE: The study was done to elucidate the clinico-radiologic predictive factors for cancerous change detected by disease progression (PD) mainly defined by interval increase in cyst size and change of cyst morphology, for branch duct intraductal papillary mucinous neoplasm (BD-IPMN) patients with relatively long-term follow-up. METHODS: Retrospective analysis of medical records and imaging findings were performed on 107 patients with BD-IPMN enrolled from July 2005 to May 2013, in whom the communication between the cystic lesion and pancreatic duct was confirmed by either endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), or endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: During the mean ± SD follow-up period of 51.5 ± 24.5 months, PD was noticed in 43 (40.2%) of 107 BD-IPMN patients. Among these 107 patients, 21 (19.6%) displayed cancerous change. By univariate analyses, septated/multilocular cyst morphology, cyst size larger than 30 mm, cyst wall thickening, mural nodules, and the presence of symptoms were significant predictive factors for cancerous changes in BD-IPMN patients. A Cox forward stepwise linear regression model revealed that cyst wall thickening (OR 9.187, 95% CI 1.883~44.820, P < 0.01) and mural nodules (OR 6.224, 95% CI 1.311~29.549, P = 0.021) were significant and independent predictive factors for cancerous change in BD-IPMN patients. CONCLUSIONS: A significant proportion of patients with BD-IPMN showed PD and cancerous change during the long-term follow-up. Cyst wall thickening and mural nodules were significant and independent predictive factors of cancerous change in patients with BD-IPMN.