Metastases to the breast

Introduction

Metastases to the breast (MB) account for 0.5% to 6.6% of breast malignancies. Diagnosis is difficult because of nonspecific clinical, radiological and histological manifestations. To plan appropriate management, it is important to differentiate MB from primary breast malignancy (PBM).

Objective

To review the clinical and imaging presentation of MB and to differentiate these from PBM.

Method

We retrospectively identified over a 15-month period six pathologically proven cases of MB from an extramammary malignancy. The clinical, ultrasound and mammographic presentations are tabulated. These are compared with the features of PBM.

Results

Primary tumours included one melanoma, two lung cancers, one lymphoma, one gynaecological malignancy and one unknown primary. The MB was the presenting feature in four out of six cases. Five patients had both mammogram and ultrasound examinations, and one of these had breast MRI in addition; one patient had ultrasound only. Imaging features were similar to those discussed in the literature and include well-defined nodules, associated axillary lymphadenopathy and an absence of distortion or microcalcifications.

Conclusion

Although radiological appearances may be helpful, MB must be differentiated from PBM by appropriate histopathologic examination, in order to preclude unnecessary mastectomy and to guide further management.