Metastatic Osteosarcoma to the Breast Presenting as a Densely Calcified Mass on Mammography.

Osteosarcoma most commonly metastasizes to the lung or the skeleton, and metastatic osteosarcoma to the breast is very rare, with only a few cases reported. Due to its rarity, little has been reported about its imaging features. In this report, we represent a 58-year-old woman with metastatic osteosarcoma to the right breast from a tibial osteosarcoma. The imaging features of the metastatic osteosarcoma to the breast by using dedicated breast imaging modalities are described. Although rare, metastatic osteosarcoma to the breast should be considered when dense calcified masses with suspicious features are seen on breast imaging in patients with a history of osteosarcoma.