Histologic parathyroid abnormalities in an autopsy series.

The parathyroid glands from 422 subjects without clinical, biochemical, or advanced histologic signs of renal disease were dissected at autopsy. The glands were evaluated histologically in relation to the subjects' age, sex, histologic renal features, other diseases, and medical therapy. Normal parathyroid glands generally had diffuse cellular arrangements, with variable fat cell content. Increased nodularity was observed, especially in enlarged parathyroid glands. Hyperplasia was present in 7 per cent and adenomas in 2.4 per cent. Hyperplastic glands were often nodular and asymmetric, and numbers of oxyphil cells were frequently increased. Some large nodules were histologically indistinguishable from adenomas. Serum calcium levels were elevated in subjects with adenomas or with hyperplastic glands containing large nodules. The findings seem to indicate that nodularity of the parathyroid tissue is a sign of abnormality and that adenomas may arise from such nodular hyperplasia. Hyperplasia and adenomas were more common in elderly subjects and in those with slight or moderate nephrosclerosis. Other diseases or medical therapy were not found to be correlated with parathyroid weight or histologic features.