<prompt> Knee with leg x- ray of an adolescent boy is shown. Probable diagnosis:Chondromyxoid fibromaOsteosarcomaBone cyst with fractureOsteitis Fibrosis cystica  <response>: Chondromyxoid Fibroma Disease of adolescent Knee X-ray Sclerotic lesion around the coex in the tibia. . Small eccentric lytic lesion which lie parallel to the long axis of the bone. Bone cyst with fracture will show a larger lesion and is mostly unilateral. Osteitis Fibrosis cystica will present with multiple lesions and also has a history of abdominal groans, psychic moans and renal stones. Osteosarcoma is a malignant lesion usually occurs above the joint. 