Heterogeneous gland size in sporadic multiple gland parathyroid hyperplasia

Background: The success rate for bilateral exploration in patients with pri mary hyperparathyroidism approaches 95%. Multiglandular parathyroid hyperpl asia accounts for approximately 10% to 30% of primary hyperparathyroidism. The incidence of recurrent or persistent hyperparathyroidism is highest in familial forms of the disease, in which multiglandular disease is more comm on; this may be due to asymmetric enlargement of parathyroid glands. Becaus e of improvements in tumor-imaging capability, some surgeons are now advoca ting unilateral exploration for primary hyperparathyroidism, but there: is limited experience concerning how often these imaging methods fail. Study Design: The outcomes of 7 patients who had sporadic primary hyperpara thyroidism with multigland hyperplasia were reviewed. We gathered demograph ic data and laboratory values and reviewed radiologic tests, surgical findi ngs, pathologic findings, and postoperative followup. Results: All patients underwent preoperative localization with ultrasonogra phy and technetium/sestamibi scans. The sensitivity of these two tests for the dominantly enlarged gland was 100% for both, but dropped to 0% and 5%, respectively, for all other enlarged glands. The sensitivity of CT and MRI for the dominant tumor was 67% (2 of 3) and 50% (1 of 2), respectively. Six of 7 patients underwent subtotal (3 1/2 gland) parathyroidectomy. The mean volume of all glands was 1.51 +/- 5.89 cm(3) compared with a mean of 5.66 +/- 11.4 cm(3) for all dominant glands and 0.123 +/- 0.1 cm(3) for all nond ominant hyperplastic glands. There was a large amount of variability betwee n the volumes of dominant and other glands as demonstrated by large SDs fro m the mean. Conclusions: There is a marked heterogeneity in gland size in patients with sporadic multigland hyperplasia, which is similar to that found in multipl e endocrine neoplasia type I. This heterogeneity may result in failure to r ecognize multigland disease if a unilateral neck exploration is performed. Intraoperative parathyroid hormone assay may prove to be an important adjun ct in this population of patients who have unsuspected multigland disease. (J Am Coil Surg 1999;188:382-389, (C) 1999 by the American College of Surge ons).