You said

"Do a pre-surgical evaluation for a bone biopsy procedure and then go over everything with the owner."

Yes.  This is the very next thing you should do now that you have seen the radiographs of the dog's bone.  Because the nature of the bone pathology is so remarkable and suggests a form of bone cancer, it is time to anesthetize the patient and obtain a small portion of the abnormal area for pathological analysis.

Congratulations! View the diagnosis here