OMG so glad you posted this here!!! I have the exact same situation!!!
I did my medical exam last week and I looked at the x-ray report today and I was like -- WTF, there was no PPD (which is a skin test) done!? I would REMEMBER if a needle poked my skin. Not to mention I have actually done multiple PPD tests in the past and it always came out negative.
It's very strange because I did not write down "Positive PPD" in the medical history questionnaire at the x-ray place. I called the panel physician's office and they were like, that's strange, we did not put that down. The panel physician's office asked me to call the x-ray place, which I did, and the latter basically said something like we put that there because the doctor's office wanted to check for TB and that I need to talk to the doctor. So, basically, kicking the ball from one to another. Eventually the person at the doctor's office said the report says I don't have TB and I'm "good to go".
:S The whole thing is very strange. Did you follow up on this? Have you submitted your application and/or passed your medical exam?