Tumor-induced neovessel formation identified by gadolinium-enhanced magnetic resonance imaging (MRI) is a commonly used marker for breast malignancy. The purpose of this study was to assess possible differences in whole-breast vascularity as measured by contrast-enhanced MRI in the ipsilateral and contralateral breasts of patients with unilateral breast malignancies.

Gadolinium-enhanced MRI of the breast using a Siemens 1.0-T scanner with dedicated breast coil was performed on 22 consecutive patients with histologically confirmed unilateral breast carcinoma. Whole-breast vascularity of the breast containing the carcinoma was estimated as increased, decreased, or similar compared with the contralateral unaffected breast. Breast vascularity was then correlated to clinical factors including tumor size, histology, multifocality, nodal involvement, and patient age and menopausal status.

Twenty patients had infiltrating carcinomas, and 2 patients had ductal carcinoma in situ. Four were multifocal. Fifteen of 22 patients demonstrated clear evidence of increased whole-breast vascularity in the ipsilateral breast containing the primary breast cancer compared with the contralateral breast. Although there was no clear correlation between the presence of increased whole-breast vascularity in the cancer-bearing breast with tumor size, histology, grade, mammographic appearance, or patient age and menopausal status, increased vascularity was present in 3 of 4 patients with multifocal disease and in 4 of 5 patients with metastatic disease in the axillary nodes.

Measurable increases in whole-breast vascularity can be identified by contrast-enhanced MRI and appear with increased frequency in the cancer-bearing breast. These findings suggest that factors other than tumor size and histology may influence development of macroscopic vessels during tumor progression and may be indicative of angiogenic tumor biology.