Parathyroid cysts are uncommonly encountered in surgical practice. Even in autopsy material, a cyst of a parathyroid gland large enough to be recognized grossly is an infrequent finding, despite the fact that cysts are commonly seen microscopically. Black and Watts1 and Castleman and Mallory2 noted microscopic cysts in 42% to 50% of parathyroid glands studied at autopsy. Perdue and Martin6 recently collected 25 parathyroid cysts of clinical significance and added one of their own. They included one of the cases reported by Fisher and Gruhn,3 which was actually an incidental finding at autopsy, so the total number of cysts that have been discovered and removed during life is 25.
Parathyroid cysts have been reported in patients 16 to 79 years of age, with a random distribution in all decades. Approximately two-thirds of the cysts have been discovered in women. The cyst usually presents as a mass