Primary osteosarcoma of the breast

Osteosarcoma occurring in the soft tissues is very rare (Rao et al, 1978). We present the findings in a patient where it occurred in the breast. An 81-year-old lady presented with a six-week history of a lump in the right breast. On examination there was a 12 cm hard mass which was infiltrating the skin and was partially adherent to deeper tissues. A mammogram (Fig. 1) revealed a well-defined dense 6 cm mass with no associated calcification. A bone scan (Fig. 2) was performed using 99Tcm diphosphonate.