Parathyroid cysts of the neck and mediastinum. Case report.

Five cases of parathyroid cyst are presented and the literature concerning this rare entity is reviewed. Three of the five cysts were located in the neck and were non-functioning. The other two were in the anterior mediastinum and functioning, and indeed were associated with hypercalcemic crisis. Four cases were treated surgically, and in one non-functioning parathyroid cyst both diagnosis and treatment were accomplished with fine-needle aspiration. The cystic appearance, color of the fluid contents, high content of parathyroid hormone and histologic features distinguish parathyroid cyst from the much commoner thyroid cyst. Non-functioning parathyroid cysts can be treated with fine-needle aspiration, whereas functioning cysts require surgical removal.