Direction of further investigation into microscopic thymoma

Thymoma plays an important role in the initiation of the autoimmune response to acetylcholine receptor (AchR), which leads to myasthenia gravis (MG) (1). Because thymoma, unlike normal thymus tissue, does not have medullary epithelial function and lacks autoimmune regulator expression, negative selection for T cells does not work efficiently. Consequently, many types of autoantibody including anti-AchR antibody are produced.