Parathyroid cysts with primary hyperparathyroidism: report of a case

Cysts of the parathyroid glands are uncommon, and, moreover functioning parathyroid cysts that cause primary hyperparathyroidism are rare. Herein is reported a 53-year-old female with primary hyperparathyroidism accompanied by 2 parathyroid cysts, in one of which adenoma was noticed. Forty-two cases of parathyroid cysts were found in the Japanese literature. Twelve of them were in the hyperparathyroid state, but infarction of the adenoma lead to cystic degeneration in most of such cases and so the cyst wall were lined with adenoma cells. In only 2 cases including our case were the cyst walls lined with cuboid cells and the adenoma evident in the wall. The pathogenesis of our case seems to be a common embryonic defect or dilatation of vestigial remnants rather than a degenerative change of the adenoma.