ABSTRACT
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.
