The thymus is a small gland that sits between the lungs and plays a critical role in the immune system. The thymus is an area where a special kind of immune cell, known as T cells, are able to develop and mature. The thymus is also important for helping the immune system distinguish between infectious cells and normal body tissue. Most diseases of the thymus affect the immune system.
Thymus Cancer
There are two main kinds of cancer that can develop in the thymus. A thymoma is a tumor in which the cancerous cells look very similar to those of normal thymus tissue. Thymic carcinomas, on the other hand, have cells that do not resemble thymus cells. Thymic carcinomas are particularly dangerous because they grow more rapidly and are more likely to spread to other tissues. Thymomas are associated with autoimmune diseases in which the immune system attacks healthy tissue. Both thymomas and thymic carcinomas can be present without causing any symptoms. When cancer of the thymus gland does cause symptoms it can lead to a cough and chest pain.
DiGeorge Syndrome
DiGeorge syndrome, explains MayoClinic.com, is a rare congenital defect that causes dysfunction of a number of different tissues. Patients with DiGeorge syndrome have a small deletion on their 22nd chromosome, known as 22q11.2, which contains between 20 and 30 genes needed for the development of many different parts of the body. One of the effects of DiGeorge syndrome is a very small or absent thymus gland. As a result of this congenital thymus disorder, patients with DiGeorge syndrome have very weak immune systems and are extremely prone to infections. Patients with DiGeorge syndrome may need to receive a thymus transplant or receive infusions of immune cells to help prevent dangerous infections.
Severe Combined Immunodeficiency
Severe combined immunodeficiency, also known as SCID, is another genetic disease which results in a weakened immune system. Children born with this disease have a severely impaired immune system. Because of the role of the thymus in helping immature immune cells develop, patients with SCID often have an atrophied thymus because of the lack of immune cells in the body. Patients with SCID require constant treatment with antibiotics and also need regular transfusions of proteins, known as immunoglobulins, to help bolster the immune system.
