PARATHYROID HYPERPLASIA IN RENAL INSUFFICIENCY

Abstract

Another case of "primary" hyperparathyroidism characterized by diffuse hyperplasia of the parathyroid glands of the wasserhelle type is reported. The histological findings in this case have been used to emphasize the contrasting character of the "secondary" hyperplasia which is described in detail on the basis of 29 cases of chronic renal insufficiency of varying grades. Whereas in the primary hyperplasias a uniform direction of differentiation of all cells to the large water-clear type is the invariable finding, in the secondary hyperplasias such uniformity is lacking. Here the glands are composed almost completely of normal sized chief cells, although a few small water-clear cells are occasionally present. The oxyphil cells are always greatly increased in number. The glands show varying degrees of gross enlargement and even when the enlargement is limited to a single gland, microscopic examination has not failed in any instance to show evident hyperplasia in the other glands as well. The criteria for the diagnosis of secondary hyperplasia are described. Comparison of cases of chronic renal insufficiency with and without bone lesions showed quantitative but not qualitative differences in the parathyroid glands, and the development of osteitis fibrosa is felt to be directly dependent on the duration of renal insufficiency. That these changes are in no way specific to renal insufficiency is shown by the fact that no qualitative differences could be recognized between the milder grades of secondary hyperplasia in nephritis and those occasionally seen in individuals without renal insufficiency, but with a variety of associated lesions varying from metastatic carcinomatosis involving bone to basophilism of the pituitary.