Intraductal papillary mucinous neoplasm of the pancreas: can benign lesions be differentiated from malignant lesions with multidetector CT?

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct clinicopathologic entity that is being recognized with increasing frequency. In 25%-44% of IPMNs treated with surgical resection, associated invasive carcinoma has been reported. Surgical resection is the treatment of choice for most IPMNs. Preoperative determination of the presence or absence of associated invasive carcinoma is crucial. The prognosis is worse if there is associated invasive carcinoma; when invasive carcinoma is present, the surgical procedure may be modified to include resection of regional lymph nodes. The spectrum of appearances of IPMN, which includes adenoma, borderline lesion, and lesions with associated carcinoma in situ or invasive carcinoma, was studied with 16-section multidetector computed tomography (CT) and histologic correlation. CT was performed with dual-phase acquisition; the reconstructed images were reviewed on a workstation with axial scrolling and interactive multiplanar reformation and three-dimensional reformation techniques. Features predictive of invasive carcinoma in IPMN at CT and other imaging studies include involvement of the main pancreatic duct, marked dilatation of the main pancreatic duct, diffuse or multifocal involvement, the presence of a large mural nodule or solid mass, large size of the mass, and obstruction of the common bile duct.