Multimodality imaging studies of intraductal tubulopapillary neoplasms of the pancreas

PURPOSE We aimed to investigate multimodality imaging findings of intraductal tubulopapillary neoplasms (ITPN) of the pancreas. METHODS This study was approved by the institutional review board with waived informed consent. A total of eight patients were histopathologically diagnosed with pancreatic ITPN in a single institution over a 6-year period. The imaging findings of dynamic contrast-enhanced computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasonography (EUS), and positron emission tomography-computed tomography (PET-CT) were reviewed and correlated with clinicopathologic findings. RESULTS Histopathologically, an invasive carcinoma component was found in 5 of 8 patients (62.5%). The median diameter of the lesions and the main pancreatic ducts were larger in ITPN with invasive carcinoma (19 mm, 13.3–98.0 mm and 13 mm, 5.9–16.3 mm, respectively) than in ITPN without invasive carcinoma (13 mm, 12.7–18.5 mm and 6 mm, 5.6–6.1 mm, respectively), but not significantly (lesions, P = 0.229 and main pancreatic ducts, P = 0.143). Pancreatolithiasis accompanied invasive carcinoma in 3 of 5 patients (60%). Intraductal solid tumors were demonstrated on CT (5/8, 62.5%), MRCP (5/7, 71.4%), and EUS (7/7, 100%). In addition, various imaging findings mimicking chronic autoimmune pancreatitis or pancreatic ductal adenocarcinoma were found in 3 patients (37.5%) on multimodality imaging. The lesion multiplicity and synchronous or metachronous biliary cancer occurred in 3 patients (37.5%), respectively. CONCLUSION Patients with associated invasive carcinoma from pancreatic ITPN may have presented a trend toward larger tumor size and dilated pancreatic duct with pancreatoliths, but the difference was not statistically significant. Further studies with a larger number of patients are needed to provide better insight into these findings. Pancreatic ITPN can show various atypical imaging findings as well as typical intraductal solid tumor on multimodality imaging. The presence of lesion multiplicity and synchronous or metachronous biliary cancer can be helpful for assisting with the diagnosis of pancreatic ITPN.