Background: Most of the available data on multiglandular disease (MGD) originate from long-term series. The spectrum of the disease has changed now because of earlier diagnosis. We decided to assess the current frequency of MGD in seemingly sporadic primary hyperparathyroidism.
Methods: MGD was defined as the finding that more than one grossly enlarged gland weighed more than 50 mg and the rim of normal parathyroid tissue was diagnostic of adenoma. Nine hundred eight consecutive neck explorations for hyperparathyroidism were performed, 624 before 1989 and 284 between 1989 and 1991, and studied retrospectively. Since 1989, oil Red O staining has been done to assess hyperfunction.
Results: When multiple endocrine neoplasia and non-multiple endocrine neoplasia familial cases of hyperparathyroidism are excluded, the frequency of MGD in seemingly sporadic primary hyperparathyroidism, 17.7% before 1989, is still 14% since then, including a 3% frequency of true multiple adenomas. With more restrictive criteria, which exclude the second enlarged gland if it weighed less than 100 mg, if it had no rim, and if oil Red O staining was negative, the frequency of MGD in sporadic hyperparathyroidism has remained 11% since 1989. Unilateral exploration had missed 78% of second enlarged glands, and preoperative imaging studies, when performed, showed more than one gland in only two of 22 cases.
Conclusions: Routine bilateral neck exploration is recommended in primary hyperparathyroidism because of a current frequency of MGD of at least 11%.