The differential diagnois of cystic masses associated with the thyroid gland includes the more common cystic thyroid nodule. Sandström1 is generally credited with describing the first macroscopic parathyroid cyst, while Goris2 was the first to describe its surgical extirpation. Parathyroid cysts are rare entities. As of 1996, there were approximately 200 reported cases in the literature.3 The exact incidence of parathyroid cysts is debatable, being observed in 0.08% to 3.4% resections of thyroid or parathyroid disease.4 In 1 study of all thyroid and parathyroid specimens examined over a 15-year period, parathyroid cysts were found in 0.6% of the specimens.5