Retropharyngeal thymus and parathyroid gland: a case report.

Cervical ectopic thymus occurs when thymic tissue arrests during its embryologic descent through the neck to the upper mediastinum. Most often it presents as an asymptomatic neck mass. Rarely does it present with airway compromise, particularly in neonates. A neonate presented with a retropharyngeal mass causing dynamic upper airway obstruction, mimicking a venolymphatic malformation. Ultimately this proved to be aberrant ectopic thymus with an associated parathyroid gland. While there have been isolated reports of thymus or parathyroid in the retropharyngeal space, none of the prior reports found both within the same patient.