Characteristically, there are zones of rarefaction with delicate subperiosteal new bone formation in the metaphysial regions of femur, humerus or spine and pelvis. X-ray reveals subepriosteal and subepiphyseal resorption of bones. Dark bands above the metaphysis called Growth Arrest Lines. Metaphyseal lucencies affects maximum growth. Osteolytic lesions seen in half of the cases and is commonest in shaft of long bones. Osteoblastic lesions are rare, occur in metaphysis. ALL may show following features on X-ray.Periosteal Reaction Metaphyseal cortical erosions Altered medullary trabeculations, subepiphyseal bone resorption.