Characterization of Pure Ductal Carcinoma In Situ on Dynamic Contrast-EnhancedMR Imaging: Do Nonhigh Grade and High Grade Show Different Imaging Features?

To characterize imaging features of pure DCIS on dynamic contrast- enhanced MR imaging (DCE- MRI), 31 consecutive patients (37- 81 years old, mean 56), including 2 Grade I, 16 Grade II, and 13 Grade III, were studied. MR images were reviewed retrospectively and the morphological appearances and kinetic features of breast lesions were categorized according to the ACR BI- RADS breast MRI lexicon. DCE- MRI was a sensitive imaging modality in detecting pure DCIS. MR imaging showed enhancing lesions in 29/ 31 (94%) cases. Pure DCIS appeared as mass type or non- mass lesions on MRI with nearly equal frequency. The 29 MR detected lesions include 15 mass lesions (52%), and 14 lesions showing non- mass- like lesions (48%). For the mass lesions, the most frequent presentations were irregular shape (50%), irregular margin (50%) and heterogeneous enhancement (67%). For the non- mass- like lesions, the clumped internal enhancement pattern was the dominate feature, seen in 9/ 14 cases (64%). Regarding enhancement kinetic curve, 21/ 29 (78%) lesions showed suspicious malignant type kinetics. No significant difference was found in morphology (P >.05), tumor size (P = 0.21), and kinetic characteristics (P =.38) between non- high grade (I+ II) and high- grade (III) pure DCIS.