Mammographically Occult Breast Cancer

Figure 1. A right axillary mass was palpated by a 62-year-old woman while she was exercising. Surgical biopsy revealed adenocarcinoma, suggestive of metastatic breast cancer. The results of physical examination and mammography of the right breast were normal. One minute after a bolus intravenous injection of gadopentetate dimeglumine (0.1 mmol per kilogram of body weight), 1.5-T, high-resolution, T1-weighted, three-dimensional, water-specific magnetic resonance imaging (MRI) of the right breast revealed an irregular mass (arrow). MRI-guided needle localization was performed, and the location of the lesion was marked with an MRI-compatible hook wire. Subsequent lumpectomy revealed a 1.2-cm invasive ductal . . .