Mucinous ductal ectasia of the pancreas

Purpose: Pancreatic mucinous ductal ectasia (MDE) is a recently described and poorly understood disorder, with few cases reported in the imaging literature. We undertook this study to describe the spectrum of CT and pancreatographic findings of MDE and to investigate the incidence of associated pancreatic malignancy. Method: The medical records, CT scans, and pancreatograms of 12 consecutive patients with pathologically proven MDE were retrospectively reviewed. There were nine men and three women, ranging in age from 37 to 72 years (mean 59 years). Results: Focal lesions involved primarily the uncinate (two patients) and head (eight patients) by CT imaging. The entire gland was involved in two patients. CT findings were variable and included focal pancreatic enlargement, a low attenuation or cystic mass, low attenuation of the entire gland, or marked ductal dilatation. Pancreatographic findings were more consistent, showing ductal dilatation with or without intraluminal filling defects, obstruction, or displacement. In all cases, findings at enodscopy were felt to be characteristic, with ductal dilatation, filling defects, or abundant mucus seen upon cannulation of the pancreatic duct. Carcinoma-in-situ was present in six cases, cellular atypia without malignancy in two, and in three cases the lesions were histologically benign. One case demonstrated invasive adenocarcinoma. No finding or group of findings on CT or pancreatography permitted differentiation between benign and malignant lesions. Conclusion: MDE can present with a variety of appearances on CT, none of which is diagnostic. Pancreatography can be diagnostic if dilatation and intraluminal filling defects are seen. Carcinoma-in-situ, invasive adenocarcinoma, or cellular atypia is present in similar to 75%, but cannot be accurately diagnosed prospectively.