Cystic parathyroid presenting as an apparent thyroid goiter.

Parathyroid cysts are rare lesions that can present clinically as low neck masses. The clinical diagnosis of parathyroid cyst can be challenging and requires a high level of suspicion as it often mimics a thyroid nodule. The cyst occasionally can cause compressive symptoms such as dysphagia or dyspnea. When it occurs in the mediastinum, it can cause recurrent laryngeal nerve paralysis. In this report, we present a patient with a hyperfunctional parathyroid cyst in association with a papillary thyroid carcinoma. In addition, we briefly discuss the current literature on parathyroid cyst. This case is unusual in its clinical presentation in that the parathyroid cyst mimicked a thyroid goiter.