Pathology and outcome of surgical treatment for lithium-associated hyperparathyroidism

Background: Hyperparathyroidism associated with long-term lithium therapy i s well described. However, few studies have clearly defined the pathologica l findings or looked at the outcome of surgical treatment. Methods: The study was a retrospective review of II patients with bipolar a ffective disorder who had surgery for lithium-associated hyperparathyroidis m. Results: Twelve patients were identified who had received lithium therapy, of whom 11 (nine women and two men, aged 46-84 (mean 65) years) had prolong ed treatment from 2 to 30 (mean 15.3) years. At operation a single adenoma was identified in six patients, whereas multigland disease was seen in five patients. All patients resumed lithium treatment after operation. One pati ent had recurrent hyperparathyroidism at 3 years, while another had an incr eased serum level of parathyroid hormone in the presence of a normal serum calcium level after 1 year. Conclusion: Hyperparathyroidism associated with lithium may be due to eithe r parathyroid hyperplasia or adenoma. Observations in the present study sup ported a true cause and effect relationship. Routine bilateral neck explora tion should be performed because of a relatively high frequency of multigla nd involvement. However, parathyroid resection should be limited to evident disease.