Metastasis of giant cell tumor to the breast: case report and review of the literature.

Breast cancer is the most common type of malignancy in women. Of all breast cancers, 0.5-3% involve metastasis of a non-breast malignancy to the breast. Metastasis of soft tissue tumors to the breast is rarely seen. In particular, metastasis of a giant cell tumor to the breast has never been reported in the literature. We present here a case of breast metastasis in a 44-year-old woman with a diagnosis of malignant giant cell tumor originating from the distal radius and metastatic to the lung, who had been treated with radiotherapy, surgery and chemotherapy.