Magnetic resonance imaging of intraductal papillomas of the breast

Purpose: To conduct magnetic resonance imaging (MRI) studies of intraductal papillomas of the breast and to establish correlations with pathologic features. MATERIALS and Methods: Magnetic resonance images of the breast from 32 patients identified with surgically resected intraductal papillomas were retrospectively analyzed. were obtained. Interpretation of the MRI findings was based on evaluation of the configuration, internal signal intensity, contrast enhancement, type of the time-intensity curve, and presence or absence of dilated ducts associated with the lesion. Intraductal papillomas of our series were classified into several MR types and were compared to each of the surgically resected specimens. Results: Intraductal papillomas of the breast were classified into 4 MR types: oval nodule in 14 patients; irregular nodule in 6, solid and cystic mass in 8; and occult lesion in 4. Each of the MR types reflected its unique pathologic features: oval nodule composed of papillary fronds surrounded by narrow luminal space inside the duct; irregular nodule of papillary fronds entirely filling up the luminal space and adhering to the duct wall, with irregular margins surrounded by fibrosis or collagenization of fibroglandular stroma; solid and cystic mass of solid nodular protrusion of papillary fronds attached to the dilated cystic duct wall; and occult lesion of 1 to 2 mm in diameter with dilated ducts. They showed various contrast enhancements and time-intensity curves. Dilated ducts associated with the lesions were recognized in 20 patients. Conclusion: Classifying the MR images of intraductal papillomas could be useful for understanding their pathologic background.