Severe dyspnea and dysphagia resulting from an aberrant cervical thymus.

A 5-month-old infant presented with severe dyspnea and dysphagia resulting from a right-sided cervical mass. At 5 months of age, a large aberrant thymus was excised, resulting in the disappearance of all symptoms. Pathological examination showed normal thymus tissue. Since the preoperative chest X-ray film showed a normal thymic shadow and the T-lymphocyte functions were normal, we conclude that this was not an ectopic gland but an undescended thymic implant.