This MRI shows a “solid” variant of aneurysmal bone cyst arising in fibula in a 14 y/o male. In such cases, the solid area are predominant and cystic spaces with septa may be inconspicuous. Histologically, they show spindle cell proliferation, giant cells, and reactive new bone formation. Image courtesy of: Bulent Celasun, MD, Ankara, Turkey. Used with permission.