An ill-defined infiltrative medullary lesion is noted involving the distal right femoral meta-diaphyseal region measuring about 7 x 9.5 x 17 cm in maximum dimensions. It expresses heterogeneous iso to hypo-intense signals on T1, mixed intermediate & hyperintense signals on T2 & T2 fat sat with constant hypointense areas corresponding to new bone formation.
Intra-lesional cystic areas with fluid-fluid levelling most appreciated on T2 & T2 fat sat W sequences. The lesion showed moderate heterogeneous post-contrast enhancement.
The lesion is associated with large soft tissue component circumferentially encasing the distal femoral shaft with infiltration of the vastus intermedius & to lesser extent vastus medialis muscles. Focal invasion of the distal femoral growth plate is also noted. Respected neuro-vascular bundle. The left thigh is unremarkable.