SPECIAL CASES Lithium-induced hyperparathyroidism

SPECIAL CASES Lithium-induced hyperparathyroidism

• Lithium-induced hyperparathyroidism occurs in 10–15% of patients treated with long-term lithium. It is generally associated with a mild elevation in calcium with failure to suppress PTH. The underlying aetiology can be either gland hyperplasia, with lithium originally thought to stimulate all parathyroid tissue, or a single adenoma, which has been shown to occur in 33–49% of cases. It has recently been suggested that the hyperparathy - roidism may be caused by interference with the parathyroid kinase C signal transduction system and the Wnt pathway . Biochemical abnormalities may resolve with discontinua tion lithium is required or where abnormalities persist following withdrawal of lithium. Minimally invasive surgery is relatively contraindicated in these patients because of the high incidence of multigland disease. Excision, however, should be limited to those glands that are obviously enlarged at exploration rather than a formal three-and-a-half-gland excision. SPECIAL CASES Lithium-induced hyperparathyroidism

• Lithium-induced hyperparathyroidism occurs in 10–15% of patients treated with long-term lithium. It is generally associated with a mild elevation in calcium with failure to suppress PTH. The underlying aetiology can be either gland hyperplasia, with lithium originally thought to stimulate all parathyroid tissue, or a single adenoma, which has been shown to occur in 33–49% of cases. It has recently been suggested that the hyperparathy - roidism may be caused by interference with the parathyroid kinase C signal transduction system and the Wnt pathway . Biochemical abnormalities may resolve with discontinua tion lithium is required or where abnormalities persist following withdrawal of lithium. Minimally invasive surgery is relatively contraindicated in these patients because of the high incidence of multigland disease. Excision, however, should be limited to those glands that are obviously enlarged at exploration rather than a formal three-and-a-half-gland excision.