Diagnosis: Cervical thymic cyst
Cervical thymic cysts are rare lesions with an unclear pathogenesis. Speer1hypothesized 5 different possibilities for the development of thymic cysts: (1) embryonal remnants of thymopharyngeal ducts, branchial clefts, or thymic tubules; (2) sequestered products of the thymus eventually undergoing pathologic involution; (3) degeneration of Hassall corpuscles; (4) lymphatics, blood vessels, or connective tissue in various stages of thymic development, hyperplasia, or involution; and (5) neoplastic processes in the lymphoreticular system. In recent years, 2 theories that gained the most support include the congenital persistence of thymopharyngeal ducts and the degeneration of Hassall corpuscles.
Radiology Quiz Case 2: Diagnosis. Arch Otolaryngol Head Neck Surg. 2008;134(10):1115. doi:10.1001/archotol.134.10.1115