thymectomy

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Related to thymectomies: thymoma, thymus

thymus

 [thi´mus]
a ductless gland lying in the upper mediastinum beneath the sternum; it reaches its maximum development during puberty and continues to play an immunologic role throughout life, even though its function declines with age. During the last stages of fetal life and the early neonatal period, the reticular structure of the thymus entraps immature stem cells arising from the bone marrow and circulating in the blood. The thymus preprocesses these cells, causing them to become sensitized and therefore capable of maturing into a specific differentiated type of lymphocyte. After sensitization by the thymus, the cells reenter the blood and are transported to developing lymphoid tissue, where they seed the cells that eventually become T lymphocytes, a type essential to the development of cell-mediated immunity. If the thymus is removed or becomes nonfunctional during fetal life, the lymphoid tissue fails to become seeded with the sensitized lymphocytes and the body's cell-mediated arm of immunity fails to develop. It is this arm of immunity that is mainly responsible for rejection of organ transplants and resistance to intracellular microbial infection, and perhaps plays a role in natural resistance to cancer.
Thymus.

thy·mec·to·my

(thī-mek'tŏ-mē),
Removal of the thymus gland.
[thymus + G. ektomē, excision]

thymectomy

(thī-mĕk′tə-mē)
n. pl. thymecto·mies
Surgical removal of the thymus.

thy·mec·to·my

(thī-mek'tŏ-mē)
Removal of the thymus gland.
[thymus + G. ektomē, excision]
References in periodicals archive ?
Thymectomies performed in treatment of myasthenia gravis at the Department of Thoracic surgery.
Thus, in accordance with the current literature, this case further supports the concept that thymectomies, as treatments for autoimmune disorders such as myasthenia gravis, may increase the susceptibility to cancers such as leukemia.
Elderly persons (4) and patients who have undergone thymectomies secondary to thymoma (5) are recognized as groups at risk for YEL-AVD.
Although a causal relationship between acquired athymia and immune dysregulation has yet to be established, thymectomies in patients younger than 3 months have been shown to result in lower numbers of circulating T cells and diminished responses to T-cell mitogens.[14] Hence, preoperative imaging studies are recommended to verify the presence of mediastinal thymic tissue prior to surgical neck exploration.