Tertiary hyperparathyroidism.

In our first 200 cases of primary hyperparathyroidism confirmed by operation 12 were also shown to have a long history either of a malabsorption syndrome or of chronic renal-glomerular failure. We consider that they first went through a phase of secondary hyperparathyroidism, during which one or more of the glands became autonomous adenamata. This then produced the biochemical changes of "primary" hyperparathyroidism, necessitating excision of the adenoma. This condition is best described as "tertiary" hyperparathyroidism. The transition from secondary to tertiary hyperparathyroidism occurred in four of the 12 patients while under our observation. We think the same process can be traced retrospectively in the other eight cases. The concept of tertiary hyperparathyroidism may help to explain the high incidence of other diseases in association with primary hyperparathyroidism.The behaviour of the parathyroid glands provides a valuable model for the investigation of tumour formation in man. All states occurred in our patients with primary hyperparathyroidism, from normal through hyperplasia to adenoma formation and finally to parathyroid carcinoma.