Giant-cell tumor of the tibia in a child presenting as an expansile metaphyseal lesion with fluid-fluid levels on MR.

Approximately two percent of giant-cell tumors (GCT) occur in the skeletally immature. The patient presented is four years old with a cystic giant-cell tumor of the tibial metaphysis. Fluid-fluid levels are demonstrated on CT and MR and likely represent the underlying pathophysiology.