Parathyroid hyperplasia: an unusual cause of neonatal hypercalcemia.

Primary hyperparathyroidism (PHPT) in infants is caused by parathyroid chief cell hyperplasia. Patients present with symptoms of chronic hypercalcemia, such as failure to thrive, irritability, abdominal pain, and anorexia. Medical therapy is inadequate, often resulting in chronic hypercalcemia or death. Partial or total surgical removal of the parathyroid gland is the preferred treatment. We describe a case of a 7-month-old infant with PHPT secondary to hyperplasia successfully treated with a subtotal parathyroidectomy.