Background: Patients receiving lithium therapy are at elevated risk of developing hyperparathyroidism. In lithium-associated hyperparathyroidism (LAH), the incidence of multiglandular disease (MGD) is unclear, and the need for routine bilateral cervical exploration remains controversial. Therefore, in LAH patients, surgical approaches, pathologic findings, cure rates, and factors associated with persistent or recurrent disease were investigated.
Methods: Retrospective analysis of 27 patients with LAH undergoing parathyroidectomy with the intraoperative parathyroid hormone (PTH) assay.
Results: The median postoperative follow-up was 7 months; 17 patients had >6 months follow-up. Cervical exploration was unilateral in 9, bilateral in 18 (3 were converted from unilateral). Sixteen patients (62%) had MGD, 12 with four-gland hyperplasia and 4 with double adenomas. Ten patients (38%) had a single adenoma. Twenty-five (93%) of 27 patients had initially successful surgery. Of the 17 patients with >6 months follow-up, two had persistent disease and two experienced recurrent disease. All patients with a single adenoma remain free of disease. Three (75%) of four patients with persistent/recurrent disease had MGD and were receiving lithium at the time of surgery. Patients with persistent/recurrent disease were older (p = 0.01) and had experienced a longer duration of hypercalcemia (p = 0.04).
Conclusions: LAH patients have a high incidence of MGD, and bilateral exploration is frequently necessary. With access to the intraoperative PTH assay, it is reasonable to initiate a unilateral approach because many patients will harbor single adenomas and can be reliably rendered normocalcemic. Patients with MGD remain at higher risk of persistent/recurrent disease.