X-rays of the forearm of a child demonstrate an expansile bubbly lesion of the mid radial diaphysis, with irregular margins, no convincing matrix mineralization and no convincing soft tissue extra-osseous mass.

Bone scans demonstrate increased uptake.

MRI elegantly demonstrates multiple fluid-fluid levels, which although non specific suggest the diagnosis of an aneurysmal bone cyst (ABC). This was confirmed on histology following resection and grafting.