MRI features of inflammatory breast cancer

OBJECTIVE. The aim of this study was to evaluate the features of inflammatory breast carcinoma (IBC) on MRI compared with mammography and ultrasound and to better define the role of MRI in patients with this aggressive disease. MATERIALS AND METHODS. A retrospective analysis was performed of patients with newly diagnosed IBC evaluated at a single institution between 2003 and 2008. Baseline MRI examinations were performed on a 1.5- or 3-T scanner using contrast-enhanced 3D T1-weighted gradient-echo sequences with parallel imaging. MRI findings were rated in accordance with the BI-RADS MRI lexicon established by the American College of Radiology. All patients underwent concomitant mammography and ultrasound examinations. RESULTS. Eighty women with a clinical diagnosis of IBC were included in the study (median age, 52 years; age range, 25-78 years). MRI detected a primary breast lesion in 78 of 80 symptomatic breasts (98%) compared with 53 of 78 (68%) with mammography (p < 0.0001) and 75 of 80 (94%) with ultrasound. Of the 78 breasts with a primary lesion, the most common MRI finding was a mass or multiple masses (57/78, 73%). Masses were frequently multiple, small, and confluent (47/57, 82%); mass margins, irregular (43/57, 75%); and internal enhancement pattern, heterogeneous (47/57, 82%). Kinetic analysis revealed a delayed washout pattern in 66 of 78 tumors (85%). MRI showed skin thickening in 74 of 80 breasts (93%), whereas mammography showed skin thickening in 56 of 78 breasts (72%). CONCLUSION. Multiple small, confluent, heterogeneously enhancing masses and global skin thickening are key MRI features of IBC that contribute to improved detection of a primary breast cancer and delineation of disease extent compared with mammography.