<prompt> Which of the following bone tumor present secondaries in lung with pneumothorax:OsteosarcomaEwings sarcomaOsteoclastomaChondroblastoma  <response>: Both osteogenic sarcoma and Ewings sarcomamay have metastasis to lung. It is much more common in osteogenic sarcoma and about 10 of patients have pulmonary metastasis by the time they are first seen. Incidence of pneumothorax is higher in osteosarcoma metastasis. 