Pancreatic retention cyst: multi-modality imaging findings and review of the literature.

PURPOSE: To investigate the multi-modality imaging presentation of the pancreatic retention cyst (PRC) with pathologic correlation.

METHODS

Imaging data including CT, MRI, endoscopic ultrasonography (EUS) and EUS guided fine needle aspiration (EUS-FNA), and endoscopic retrograde cholangiopancreatography (ERCP) in fifteen patients (five males and ten females; mean age, 44.5 years) with pathologically proven PRC were analyzed retrospectively, and imaging features were correlated with pathological findings.

RESULTS

Sixteen PRCs of 15 patients were included in this study. The mean size of PRCs was 4.4 × 4.6 cm (range 0.5 × 0.6-8.1 × 10.1 cm). PRC were round (n = 11), oval (n = 2), or lobular (n = 3). Punctiform calcification of the wall on CT (n = 2), thin septa (n = 4), thin wall (n = 3), and dilation of upstream pancreatic duct (n = 6; mean diameter, 4.3 mm) were detected. Dilation of upstream pancreatic duct was smooth in five PRCs and irregular in one PRC with pancreatic duct with punctiform calcification. Communication of PRCs with pancreatic duct was seen in two patients (one on CT, one on ERCP). Pancreatic inflammation and neoplasm were detected in four and two patients, respectively.

CONCLUSIONS

PRC typically presents as a well-defined, round cystic lesion, and different associated pathologic conditions including pancreatic inflammation and neoplasm may be detected in some patients on the multi-modality imaging examinations. Smooth dilation of upstream pancreatic duct with uncommon communication to the cyst may be helpful for the differentiation. Combination of a variety of imaging modalities could contribute to improve the diagnosis.