What is the immediate next step that should be suggested for this patient?
Image the rest of the lesion! It's always prudent to make sure you are aware of the true extent of the process you are dealing with; therefore, if something you are interested in extends beyond the field of view, you should recommend obtaining more imaging to asses the entire lesion.
The proximal right femur shows a diffusely abnormal irregular trabecular pattern with areas of increased and decreased osseous density and ground-glass opacity. This lesion causes moderate cortical thinning with endosteal irregularity. There is no associated periosteal reaction or definitive soft-tissue mass. The proximal epiphysis of the right femur is spared. Similar lesions are present within the right ilium in the supra-acetabular region and along the iliac crest. The right femoral neck demonstrates a focally expansile lytic lesion with severe cortical thinning which appears to be a distinct lesion from the changes described previously. The cortex along the inferior margin of the right femur is not definitively intact, and may represent an area of cortical disruption indicating a pathological fracture.