Summary

Background: Magnetic resonance imaging of the breast has emerged as a valuable imaging tool in addition to conventional imaging modalities. It has high sensitivity for malignant lesions, and can detect mammographically, sonographically and clinically occult cancers. “MR only” lesions are best biopsied under MR guidance; however, this may be a challenging task.

Objectives:  To evaluate our initial clinical experience with MR-guided core needle breast biopsy and MR-guided needle localization.

Methods: We retrospectively evaluated 81 women with 97 lesions, who were scheduled for guided core needle biopsy or MR-guided needle localization followed by surgery. Lesions were categorized as malignant, high risk, or benign according to the BI- RADS MR classification system. MR findings were compared with final histopathology or with follow-up imaging findings.

Results: Fifteen (16%) lesions were malignant (9 invasive ductal carcinoma, 2 invasive lobular carcinoma, 4 ductal carcinoma in situ); 7 (7%) lesions were high risk (4 atypical ductal hyperplasia, 3 radial scars); 75 (77%) lesions were benign, mainly fibrocystic changes. Other benign findings were sclerosing adenosis, pseudoangiomatous stromal hyperplasia, fat necrosis, intraductal papilloma, fibroadenoma, capillary hemangioma, and florid ductal hyperplasia. No major complications were encountered.

Conclusions: MR-guided interventional procedures of the breast are accurate, safe and feasible methods for sampling breast lesions detected only by MR and have become a significant tool in the management of certain patients.