<prompt> Babu a 19 yrs old male has a small circumscribed sclerotic swelling over diaphysis of femur; likely diagnosis is -OsteoclastomaOsteosarcomaEwing sarcomaOsteoid osteoma  <response>: Well circumscribed sclerotic swelling over diaphysis of a long bone femur in a 19 years old suggests the diagnosis of osteoid osteoma. 