I had a CT Scan done and got the results. It apperas there is some soft tissue surrounding my thymus. The thymus is responsable for autoimmune diseases.
Thymus - organ serving as the site of T cell differentiation.
Crohn's disease and myasthenia gravis: a possible role for thymectomy
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1374509
http://www.harvardscience.harvard.edu/medicine-health/articles/shadow-proteins-thymus-may-explain-how-immune-system-gets-know-its-own-body
Researchers recently identified a protein that appears to work by turning on in the thymus, which lies beneath the breast bone, the production of a wide array of proteins from the body's periphery. The discovery of the protein called "aire" could shed light not only on how the healthy immune system develops tolerance to its own proteins but also how tolerance is lost, as it is in diabetes, rheumatoid arthritis, Crohn's disease and other autoimmune illnesses.