[Primary hyperparathyroidism--pathological findings and ultrastructure]

Primary hyperparathyroidism may be caused by one or two benign tumors in separate glands, adenoma, a malignant tumor of one gland, carcinoma or hyperplasia of all four glands. Pathologically, the main problem lies in distinguishing between primary chief cell hyperplasia and adenoma, it is impossible from pathological findings of only one gland. Parathyroid adenomas and chief cell hyperplasias contain large numbers of active chief cells. The cells contain aggregated arrays of rough endoplasmic reticulum and large, complex Golgi apparatus with numerous vacuoles and vesicles. Secretory granules are often present in these cells. Most of the cells are generally interpreted to be in the more active phases of parathyroid hormone synthesis and secretion.