Local recurrence of a phyllodes tumour of the breast presenting with widespread differentiation to a telangiectatic osteosarcoma.

Osteogenic sarcomas of the breast are extremely rare and need to be distinguished from a variety of breast lesions producing metaplastic bone. A 50 year old patient presented with a painless lump in her right breast after twice previously having undergone local excision of a phyllodes tumour at this site. Following radiological and cytological investigation, excision was advised. Histology showed focal remnants of the previously excised phyllodes tumour in continuity with areas of widespread differentiation towards a telangiectatic osteosarcoma. So far this is a unique morphological endpoint.