What part does the thymus gland have in myasthenia gravis?
The thymus gland is a small gland at the upper chest just behind the sternum (breastbone). It is part of the immune system. The thymus is abnormal in many people with myasthenia gravis, particularly in those who develop myasthenia gravis before the age of 40. The exact role of the cells in the thymus is not clear but they may have something to do with ‘programming’ or making antibodies against acetylcholine receptors. For some people, removal of the thymus gland by an operation cures their myasthenia gravis. A small number of people with myasthenia gravis develop a tumour (growth) of the thymus gland called a thymoma. If it occurs it is usually benign (non-cancerous) but it is malignant (cancerous) in a very small number of cases.
