<prompt> In a young boy, x-ray of the upper end of the tibia shows a lytic lesion. The least likely diagnosis is-Giant cell tumorOsteosarcomaSolitary bone cystTuberculosis  <response>: Giant cell tumour occurs between 20-40 years not in a young childTelangiectatic type of osteosarcoma, solitary bone cyst and tuberculosis can cause an osteolytic lesion in a child. 