Swelling over distal end of femur with secondaries in lungs, diagnosis is:

Ans. is 'a' ie Osteogenic sarcoma Osteosarcoma are aggressive lesion and metastasize widely through the blood stream; usually first to the lungs.Ewing's sarcoma also metastasizes, to lung & bones. Bone to bone metastasis are more commonOsteoclastoma rarely metastasizes.Thus this lesion could be either osteosarcoma or Ewing's sarcoma but osteosarcoma would produce swelling at distal end of femur (b/c it arises from metaphysis) and Ewing would not be placed distally b/c it arises from the diaphysis.