Background: Are double parathyroid adenomas a discrete clinical entity or are all hyperplastic parathyroid glands of varying size? This investigation was done to determine whether patients with persistent or recurrent hyperparathyroidism and double adenomas (DA) differ in clinical profile or in response to treatment from patients with hyperplasia.
Methods: From 1982 to 1993, 37 unselected patients with persistent (11) or recurrent hyperparathyroidism (26) were treated. Twenty-one had DA and 16 had hyperplasia. DAs were defined as two abnormal and two normal parathyroid glands.
Results: Patients with persistent or recurrent hyperparathyroidism caused by DA were older and had more muscle weakness, neuropsychiatric disorders, constipation, and weight loss (p < 0.001) than patients with persistent or recurrent hyperparathyroidism caused by hyperplasia. Nephrolithiasis was more common in patients with recurrent hyperparathyroidism caused by hyperplasia than in patients with recurrent hyperparathyroidism caused by DA (p < 0.001). Serum Ca2+ levels before operation were similar in these groups with variable parathyroid hormone levels. No recurrences occurred in either group (DA [mean, 6 yr]; hyperplasia [mean, 5 yr]). Postoperative levels of serum Ca2+ and parathyroid hormone were normal in both groups.
Conclusions: Patients with persistent or recurrent hyperparathyroidism caused by DA are older, have different clinical manifestations, and are cured by resection of the second adenoma. These findings support the concept that DA and hyperplasia are distinct entities.