Congenital Anomalies of the Thymus

Abstract

The thymus, a retrosternal lymphoid tissue, develops from the third and fourth pharyngeal pouches like the parathyroid glands at the sixth week of gestational age. The thymus is usually located in the anterior mediastinum, although it can be found anywhere in the thymopharyngeal path. The thymus has a bilobed or quadrilateral shape; however, it can be found in other shapes. Limited information is available about the precise epidemiology of thymic congenital anomalies. Since these anomalies are not symptomatic, it may be more common than the available reports. There are various reports available about the prevalence of thymic diseases and anomalies ranging from 4.45 to 30%. In this chapter we tried to have a review on epidemiology, definition, and management of congenital anomalies of the thymus.