Solitary cystic tumor of the pancreas: EUS-pathologic correlation

Background: It is clinically important to distinguish neoplastic from nonneoplastic pancreatic cysts. Methods: Retrospective correlations were made between pathologic and EUS data from 52 pancreatic solitary cystic tumors: mucinous cystadenoma (10), mucinous cystadenocarcinoma (7), serous cystadenoma (5), ductectatic mucinous cystic tumor (10), solid and papillary epithelial neoplasm (5), and non-neoplastic cyst (15). The mean tumor size was 3.5 cm (range, 1.2 cm to 6.0 cm). Results: Six classifications of the internal structures of these cysts were developed: thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type, and simple type. Although all neoplastic cysts belonged to the first four types, all non-neoplastic cysts belonged to the last two types. The accuracy of EUS for differentiating tumors was estimated at 96% and 92%, respectively, by two observers. Conclusions: EUS may become a mandatory modality for differentiating pancreatic solitary cystic tumors and choosing an optimal treatment.