Primary mammary osteosarcoma

Primary mammary osteosarcoma is a rare entity. There are only a few reports in the literature that have focussed on its clinical behavior, histological features and treatment. Pure osteosarcoma needs to be distinguished from those arising in phylloides tumour or carcinosarcoma. It may arise from metaplastic sarcomatous transformation of neoplastic cells in primary breast carcinoma, fibroadenoma, malignant phylloides tumour. It may exceptionally represent non phylloides sarcoma arising from the soft tissues of an otherwise normal breast. The present case is a 60 year old female in whom modified radical mastectomy was done for lump in right breast which on histopathology revealed primary mammary osteosarcoma.