Recurrent acute primary hyperparathyroidism in an adult male patient.

OBJECTIVE

To report the occurrence of recurrent acute primary hyperparathyroidism (HPT), a rare disorder that occurs in only 1 to 2% of patients with primary HPT.

METHODS

We describe a patient who had two separate episodes of acute primary HPT and discuss the appropriate treatment of parathyroid crisis.

RESULTS

In 1990, primary HPT developed in a 41-year-old man, who underwent surgical removal of a parathyroid adenoma. He remained normocalcemic until 1995, when acute primary HPT developed after lithium therapy was initiated because of depression. Calcium and parathyroid hormone (PTH) levels declined after lithium therapy was discontinued, but they remained slightly above the normal range. Nine months later, he was rehospitalized with acute primary HPT. After stabilization, a second parathyroid adenoma was successfully resected, and calcium and PTH levels subsequently remained normal. In this disorder, levels of PTH are increased up to 20 times normal, and the clinical manifestations are similar to parathyroid carcinoma. Treatment involves rehydration, antiresorptive agents, and parathyroidectomy. Our patient initially was thought to have lithium-induced primary HPT, which can occur in up to 10% of patients on long-term lithium therapy. The mechanism is unknown but may be an alteration of the calcium-PTH "set-point."

CONCLUSION

Patients with asymptomatic primary HPT should have close follow-up because of the risk of development of acute primary HPT. Patients at risk, such as those with immobilization or severe illness, should be identified. Drugs known to interfere with calcium metabolism (for example, lithium) should be avoided in patients with primary HPT.