Parathyroid incidentalomas in normocalcemic patients during thyroid surgery.

The aim of this study was to compare the clinical, biochemical, and pathologic findings of normocalcemic patients with macroscopically enlarged parathyroid tissue identified at thyroid surgery with those of patients treated surgically for preoperatively proved primary hyperparathyroidism (PHPT). The records of 28 patients with incidental parathyroid enlargement and 533 patients with PHPT were reviewed to compare age, sex, serum calcium and phosphate, intact parathyroid hormone (iPTH), parathyroid weight, number of diseased glands, cell and histologic types, PTH content, and cure rate. Incidentally found lesions were lighter and developed in younger patients. Biochemistry and pathology found them to be less hyperfunctioning. Sex, number of diseased glands per patient, and cell type were not different. PTH content was low in the incidental lesions. Incidentally discovered enlarged parathyroid glands are mildly hyperfunctioning at the time of discovery. They may represent an early stage of lesion responsible for overt PHPT. In the absence of knowledge concerning their significance and evolution, we recommend that enlarged parathyroids found during the course of a thyroid operation be removed.