Parathyroid cysts: report of the sixth and youngest pediatric case.

A nonfunctioning parathyroid cyst occurred in an 8-year-old girl, the youngest patient reported to have this diagnosis. Most cysts are asymptomatic; a few are associated with signs and symptoms of hyperparathyroidism. In asymptomatic patients with a lateral neck cyst, aspiration of clear fluid with an elevated parathyroid hormone level is diagnostic of a parathyroid cyst. If this results in disappearance of the cyst, without recurrence, no further treatment is necessary. If the cyst recurs, aspiration may be repeated. However, persistence of the cyst despite aspiration or recurrence after the second aspiration should prompt surgical removal, with intraoperative identification of all parathyroid glands, because functioning parathyroid cysts are associated with a high risk of hyperplasia or adenoma.