- An expansile cystic multilocular osteolytic lesion is seen at the metadiaphyseal region of the left humerus, adjacent to the unfused epiphyseal plate with internal multiple fluid-fluid levels.
- Associated thinning out of the overlying cortex with focal cortical interruption noted along its lateral aspect.
- It appears of low to intermediate signal on T1 and of mixed intermediate and bright signal on T2. STIR weighted images showing fluid/fluid levels.
- No extra-osseous soft tissue masses or periosteal reaction.
- Diffuse edema of the surrounding upper arm musculature is noted.
- Mild shoulder joint effusion.