I Have pain

Myasthenia gravis and back pain between shoulder blades

 As like others like my self I was treated for a thymoma on my thymus.
The location of the thymus gland and thus the thymoma is in the middle of the chest right below the lungs behind the chest bone. That is why in the Myasthenia gravis operation, the surgeon has to literally saw the chestbone apart to get to the thymoma and put the chest bone back together again. It is an open chest bone sawing operation.
That location projected to the back is exactly between the shoulder blades.
This brings us to two situations: (1) pre-surgery Myasthenia gravis; and (2) post-surgery Myasthenia gravis.
(1) In pre-surgery Myasthenia gravis, the pain is due to the thymoma. (2) In post-surgery Myasthenia gravis, the pain is a phantom pain. However, due to the surgery, the healing of the cut wound of the chest bone will tighten the chest muscles and the shoulder blade muscles.