LeukemiaDark bands above the metaphysis called Growth Arrest Lines. These translucent transverse metaphyseal bands are the earliest & characteristic findings. Metaphyseal lucencies affects maximum growth. Characterstically, there are zones of rerefaction 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. Osteolytic lesions seen in half of the cases and is commonest in shaft of long bones. But any bone can be involved. Osteoblastic lesions are rare, occur in metaphysis → Metaphysial osteosclerosis. ALL may show following features on X-ray. Periosteal reaction (periosteal new bone formation) Metaphyseal cortical erosions Altered medullary trabeculations, subepiphyseal bone resorption.