Your thymus gland is located behind your breastbone and plays a vital role in healthy immune system development. The thymus is a fairly large gland during childhood, that slowly shrinks after puberty. This atrophy is due to the increased circulation of sex hormones.
When you were born your immune system was not completely developed. One of the immune shortcomings at birth is the lack of mature T cells, a type of lymphocyte. Lymphocytes are your protectors against a foreign organisms invasion, i.e. bacteria.
Your thymus gland is where generic lymphocytes mature into T cells with the help of a thymus secreting hormone. And from there they are disseminated via your bloodstream to your lymph nodes and other lymph tissue. Your thymus also secretes hormones that help develop the lymphoid system.
Normally, within a few months after birth your immune system has matured enough to adequately protect you throughout your life. However, one of the thymus related problems is not having one, either you were born without one or a health reason caused it to be removed shortly after your birth. Essentially, if you are without a thymus during the first couple months of life, then you will likely suffer from immune deficiency the rest of your life.
Some other thymus gland problems include thymoma, thymus cancer and hyperplasia, or enlarged thymus. And these health conditions are most commonly associated with myasthenia gravis.
Thymoma and thymus cancer are rare tumors growing on the outside of the thymus. A thymoma is potentially cancerous and thymus cancer is malignant. And since your thymus contains different types of cells, other types of cancer can develop as well.
When symptoms are present with thymoma or thymus cancer, then you may experience:
The cause of thymoma and thymus cancer is unknown.
Although myasthenia gravis has the most common association with thymoma and thymus cancer, they do occur in those experiencing certain immune system issues, autoimmune disorders, nonthymic cancers, bone disorders, collagen diseases, endocrine disorders, renal disease and skin diseases, like:
- Crohn’s diseae
- acute leukemia
- Grave’s disease
- ulcerative colitis
- Whipple disease
- low blood counts
- hemolytic anemia
- multiple myeloma
- Sjogren syndrome
- Cushing’s disease
- Addison’s disease
- myotonic distrophy
- rheumatoid arthritis
- nephrotic syndrome
- autoimmune pure red cell aplasia
An enlarged thymus is treated differently based on whether the gland itself is normal but the size is too big for your particular age or whether its larger size is caused by an increased number of lymphoid follicles. The former having to do with overgrowth after the cessation of severe systemic stress, known as rebound hyperplasia. The latter is often associated with:
- Graves disease
- Behcet disease
- Addison disease
- rheumatoid arthritis
- polyarthritis nodosa
- Hashimoto thyroditis
- autoimmune hemolytic anemia
Treatment for hyperplagia will depend on your particular cause for an enlarged thymus.