Abstract
Osteosarcoma is the most common skeletal malignancy and commonly metastasis to lung and bone. Here we report a case of osteosarcoma of the right knee with metastasis to the lower and inner quadrant of the breast along with axillary, mediastinal, retroperitoneal and inguinal lymphadenopathy with lung and liver metastasis. The diagnosis of breast metastasis was confirmed by ultrasonography-guided biopsy and immunohistochemistry (IHC). So this report highlights the rarest metastasis to breast and axillary lymph node from an osteosarcoma of the right knee primary.