Double adenoma as a cause of primary hyperparathyroidism: As
• Double adenoma (DA) occurs in almost 10% of patients undergoing initial surgery for PHPT.

• Rates of recurrent/persistent disease is similar in DA and four-gland hyperplasia. In a multivariate model, DA is associated with a higher risk of failure to cure.

• Low-normal IOPTH is associated with decreased risk of persistence/recurrence. Careful use of IOPTH may minimize the risk of failure to cure in DA.

Primary hyperparathyroidism (PHPT) caused by double adenoma may carry a higher risk of failure to cure. The Researchers compared outcomes in single adenoma (SA), double adenoma (DA), and four-gland hyperplasia (HP). Patients undergoing initial parathyroidectomy for PHPT were categorized by diagnosis. The primary outcome was persistent/recurrent disease postoperatively.

Of 3408 patients, 81.3% had SA, 9.5% had DA, and 9.3% had HP. Rates of persistence/recurrence were 2.9%, 5.3%, and 4.5% in SA, DA, and HP, respectively. Patients with persistence/recurrence had higher preoperative calcium and PTH, and lower rates of IOPTH normalization. On multivariable analysis, DA was associated with an increased risk of persistent/recurrent disease. Most patients with DA are cured with the removal of two glands, but approximately 5% experience disease persistence/recurrence. Low-normal final IOPTH was associated with a lower risk of persistent/recurrent disease.