Endocrine Abstracts

Abstract: The incidence of multiglandular parathyroid disease (MGD) varies in the range 7–33%. Negative preoperative imaging is a strong predictor of MGD in patients with primary hyperparathyroidism (PHPT). We retrospectively evaluated a cohort of 13 patients with PHPT and inconclusive MIBI scintigraphy and/or neck ultrasound (mean age 64 years, total calcium 2.74 mmol/l and parathyroid hormone (PTH) 114 ng/l). All subjects subsequently underwent additional imaging with flurocholine PET/CT (FCH) prior to surgery. In 10 of 13 patients a single parathyroid adenoma or hyperplasia were found whereas 3 patients had MGD (23%). In one patient with negative MIBI and ultrasound FCH showed three active foci. Two enlarged parathyroid glands were found at surgery (one oxyphil hyperplasia and one chief cell adenoma). In two patients a single enlarged parathyroid gland was excised. Histopathology confirmed one chief cell adenoma and one hyperplastic gland. In both cases hypercalcemia, however, persisted. After FCH imaging both patients underwent a successful reoperation of the second enlarged gland (one hyperplasia and one chief cell adenoma). In conclusion, sporadic MGD was present in 3 of 13 patients with PHPT and inconclusive conventional imaging. Two subjects with MGD had to undergo the second neck surgery for persistent hypercalcemia. Interestingly, the excision of a single pathologically enlarged parathyroid gland did not change their calcium and PTH in comparison with preoperative levels. These two enlarged parathyroid glands were not probably hypersecreting and functional. The question how the additional enlarged parathyroid glands contribute to a clinical picture of PHPT in patients with sporadic MGD remains to be elucidated.