DESCRIPTION:
On plain films there is a diaphyseal mass in the right proximal femur with a permeative, destructive pattern with an ill-defined margin. There is a combination of osteolytic and sclerotic areas throughout the bone. The aggressive pattern extends up into to the metaphysis but does not appear to involve femoral head.

Distally the lesion extends distally into the medullary cavity with evidence of scalloping or saucerization, best seen on the frog-leg view further down from the mass which continues to suggest erosion into the cortex. Extent of soft tissue involvement is difficult to discern on the plain films. In the middle of the mass there is a pathologic fracture which shows sclerosis signifying an older healing fracture. The massive soft tissue involvement is suggested by the plain films but is better appreciated on the MRI. These images also confirm the significant involvement of the cortex distally.