ULTRASTRUCTURAL PATHOLOGY OF PARATHYROID-GLANDS IN HYPERPARATHYROIDISM - A REPORT OF 69 CASES

The ultrastructural features of 69 parathyroid glands from 43 patients with hyperparathyroidism were studied to distinguish between differen t parathyroid lesions causing hyperparathyroidism. Samples came from 4 4 cases of hyperplasia, 21 of adenoma, 3 of carcinoma, and 1 from a hi stologically normal gland. To establish the diagnosis we took into acc ount intraoperative findings during surgery as well as light microscop ic examination. Ultrastructural features, evaluated on a semiquantitat ive scale, were correlated with diagnostic, clinical, and biochemical parameters. Neoplastic glands were heavier than nonneoplastic ones, an d carcinomatous glands were heavier than adenomatous glands. Our findi ngs suggest that the cellular membrane of adenomatous glands shows mor e folding than that of hyperplastic glands, mainly in the capillary po le. Carcinomatous glands show the greatest degree of irregularity, wit h the formation of microvilli-like projections. Hyperplastic glands, i n turn, are richer in glycogen deposition. Secretory granules appear i n higher amounts when the serum calcium level is high. These findings are not of diagnostic value by themselves, but they can be taken in co nsideration to aid in differential diagnosis.