Thymic cyst in the neck.

A rare case of a thymic cyst in the neck containing both thymus and parathyroid tissue in a 7-year-old boy is presented. The clinical presentation, diagnostic evaluation, surgical management and histopathological features are described. The embryology of cervical thymic cysts and the differential diagnosis of cystic neck masses in children are briefly reviewed. The diagnosis is seldom made preoperatively. Surgical resection is the treatment of choice for definitive diagnosis, resolution of symptoms and cure.