Madnurse,
Are all the doctors you are seeing aware of your abnormal CT scan? The abnormality with your thymus along with your sx seems like it'd be a no-brainer. Plus, you have another AI disease already.
Have they done the antibody test yet?
I wish you luck in getting the correct diagnosis. It seems like MG to me, but I'm no doc- just another MG sufferer.
Take care

Nicky