<prompt> A 25-year-old male presents with swelling over right knee since 1 month. The radiograph is shown here. Which of the following statement is true regarding this condition?It is a bone forming primary malignant tumour of boneCodmans triangle can be seenHematogenous spread with lung metastasis are common.All of above  <response>: Osteosarcoma This primary malignant bone-forming neoplasm is rare, but is still the commonest primary malignant lesion of bone after myeloma. 