What Does Bone Marrow Problems Causing Sore Hip Mean?

Hi, my friend (33-year-old female in otherwise good health) has had a sore hip/lower back for a month and had an MRI done two days ago. They told her it showed a "bone marow problem" in her back and now she's to take some lab tests. Is there any indication of what this might possible mean? They did not even give her a range of possibilities.