COMBINED PRIMARY AND SECONDARY HYPERPARATHYROIDISM: TWO CASE REPORTS AND A REVIEW

Abstract
The cases reported are of 2 types - the first showing primary renal disease with secondary parathyroid hyperplasia and a parathyroid (chief cell) adenoma. In the second, the renal lesion is nephrocalcinosis. In addition there is secondary hyperplasia of the parathyroid gland and a chief cell adenoma. The 2 cases reported here are supplemented by 5 cases which were culled from the world literature. In a number of instances, the serum Ca was normal or elevated despite elevated blood urea nitrogen and inorganic phosphate. It is argued that in view of the evidence that hypocalcemia is the predominating stimulus to parathyroid hyperplasia, some of the Ca must be present in "complexed" form with citrate or other weak inorganic acids and the total ionized serum Ca remains low.