Aberrant cervical thymus in children: three case reports and review of the literature.

Aberrant migration of thymic tissue occurs with ectopic thymus in the mediastinum, base of the skull, tracheal bifurcation, and cervical region. A recent review of the literature showed a total of 76 reported cases of aberrant thymus or thymic cysts in patients who presented with primary neck masses. We report three additional cases of ectopic cervical thymus. All three patients presented with asymptomatic cervical masses, and preoperative diagnosis included branchial cleft cyst, cervical lymphangioma, and cervical teratoma. All patients underwent complete surgical resection of the masses. Aberrant cervical thymus rarely produces symptoms because it does not invade contiguous strictures. Despite its rarity, it should be considered in the differential diagnosis of asymptomatic neck masses in children.