Oxyphil cell adenoma and hyperparathyroidism.

Although the oxyphil cells of the human parathyroid generally are not thought to be involved in the secretion of parathyroid hormone, there have been numerous reports in the literature describing functional oxyphil cell adenomas. We reviewed 453 consecutive parathyroid explorations in 446 patients over a 13-year period and identified 15 patients whose hyperparathyroidism had been caused by adenomas composed almost exclusively of oxyphil cells. All patients were relieved of their hypercalcemia postoperatively, and there have been no recurreness during a mean follow-up of 40 months (100% follow-up). Three patients have died, all without evidence of recurrent hyperparathyroidism at the time of death. Immunoperoxidase and ultrastructural studies confirm that oxyphil cells from these adenomas contain parathyroid hormone and suggest that they are capable of secretory activity. A review of the literature showed that functional oxyphil adenomas occur more frequently than is usually appreciated, although they are an uncommon cause of primary hyperparathyroidism.