Extension of ductal carcinoma in situ: histopathological association with MR imaging and mammography.

The purpose of this study is to evaluate the capability of breast MRI (magnetic resonance imaging) and mammography in determining tumor extent and the detectability of ductal carcinoma in situ (DCIS) in association with histopathological features. Thirty women with breast cancer underwent 3D dynamic MRI. Twelve women had pure DCIS and 18 women had DCIS with microinvasion. We analyzed the results of preoperative MRI and mammography with histopathologic results, retrospectively. The mean lesion size was 55.1 mm from the histopathologic results. Twenty-six lesions were detected through the MRI (a sensitivity of 86.7%). MRI depicted eight lesions without mammographically detected microcalcification. In seven cases, MRI showed tumor extent accurately compared with mammography, and the combined diagnosis improved the accuracy of evaluating tumor extent. MRI can complement mammography in guiding surgical treatment of DCIS by providing better assessment of the extent of the lesion.