<prompt> Which one of the following bone tumors typically affects the epiphysis of a long bone?OsteosarcomaEwings sarcomaChondroblastomaChondromyxoid fibroma  <response>: Ans. is c ie chondroblastoma Ref: Apleys, 8e, p177.Apleys - X-Ray shows a rounded, well demarcated radiolucent area in the epiphysis; this site is so unusual that the diagnosis springs readity to mind; However, sometimes the lesion extends across the physeal line.Remember 