Inflammatory breast carcinoma in magnetic resonance imaging: a comparison with locally advanced breast cancer.

RATIONALE AND
OBJECTIVES: Although inflammatory breast carcinoma (IBC) accounts for 1%-4% of all breast cancer cases, the appearance of this highly malignant tumor in magnetic resonance imaging (MRI) is still not well characterized. The aim of this study was to identify typical imaging features of IBC in comparison with noninflammatory locally advanced breast carcinoma (LABC).
MATERIALS AND METHODS: MRIs of 48 patients with IBC were compared with an equivalent cohort of 52 subjects with LABC. Age and histopathologic subtype were equivalent between the two groups. To delineate characteristic features, a multitude of dynamic and morphologic parameters were evaluated using T1- and T2-weighted sequences.
RESULTS: No significant differences of prevalences could be found for the following criteria: dynamic tumor signal characteristics, prominent vessels, perifocal edema, axillary lymph node involvement, morphology of focal masses, and morphologic pattern of non-mass like enhancement. Otherwise, the quantity of focal masses and the spatial distribution of the tumoral infiltration significantly differed between the two cancer groups. The following parameters occurred more frequently in the IBC cases: edema (cutaneous/subcutaneous 81.3%, perimamillar 70.8%, diffuse 89.6%, prepectoral 72.9%, intramuscular pectoral 41.7%), thickening (75.0%) and pathologic enhancement (60.4%) of Cooper's ligaments, skin thickening (83.3%), punched-out sign (initially strong, focal increase of some dermal or subcutaneous parts followed by slow-continuous enhancement of the surrounding skin; 56.3%).
CONCLUSIONS: Inflammatory breast carcinoma seems to represent a specific biological entity resulting in typical MRI characteristics. Some of the parameters are supposed to visualize the characteristic extensive lymphovascular infiltration and therefore may improve the diagnosis of IBC.