Parathyroid hyperplasia in primary hyperparathyroidism: a review of 85 cases.

Parathyroid hyperplasia of all four glands was found to be the cause of primary hyperparathyroidism in 85 of 557 cases seen at the Massachusetts General Hospital between 1930 and 1973. There were 66 cases of chief cell hyperplasia and 19 cases of clear cell hyperplasia that were grossly, microscopically, and ultrastructurally distinct. Although the clinical findings overlap, there are several differences in the signs and symptoms between these two forms of hyperplasia. Both types are treated by subtotal removal of all the parathyroid tissue. Removal of insufficient tissue has left residual hyperparathyroidism in 45% of those with chief cell hyperplasia and 11% of those with clear cell hyperplasia after what was thought to be definitive surgery. Postoperative hypoparathyroidism was found in 15% of the patients with chief cell hyperplasia and in none with clear cell hyperplasia. These findings further suggest that removal of three and one-half glands in the more than 86% of patients with one gland involvement (adenoma or carcinoma) as the cause of primary hyperparathyroidism is unwarranted.