which test do I need?

I have pain in my "sit bone" (ischial tuberosity on the left side) that began with severe back pain after I lifted a heavy piece of furniture 2 months ago.  The back pain went away in 2 days, but the "sit bone" pain continues. My GP ordered an L/S spinal MRI which was negative and said I did not need a pelvic MRI. I am worried about a bone metastasis and have 2 questions: 1) Should I now contact my oncologist and ask for more tests, and which tests should I ask for, a bone scan? 2) Does breast cancer metastasize to the ischial tuberosities?  I was diagnosed with stage 3 breast cancer 5 years ago and have been cancer free since treatment.  Sorry i also posted this question on the community forum (thought I was on the expert forum) Thank you

[Cleveland Clinic]

Dear Cassandra03, Without being able to evaluate including discussion, examination, review of scans, questioning etc. it is difficult to advise specifically.  Breast cancer can metastasize to the bone, including the ischial tuberosity.  However, with the recent injury it would be more likely to attribute the pain to the injury.  Further evaluation of the pain could be done by your GP or your oncologist.  As it has been started by the GP they may want to continue the work-up which might include a bone scan.   You may want to alert your oncologist about the situation, and perhaps the GP and oncologist could discuss.  

[japdip]

This certainly sounds more like it's related to the injury than bone mets. I suppose you could ask your Oncologist but your Primary Care Physician could certainly order a bone scan which might show something different from the MRI results. Perhaps you might consider seeing an Orthopaedic Physician regarding the lingering pain.