Parathyroid pathology in hyperparathyroidism secondary to chronic renal failure.

Weights and histopathological changes in parathyroid glands were evaluated in relation to clinical and biochemical parameters in 42 patients who underwent parathyroidectomy for hyperparathyroidism (HPT) secondary to chronic renal failure. There was a positive relation (r = 0.71, p less than 0.01) between duration of renal insufficiency and total parathyroid glandular weight. The glandular weight was also closely related to the serum levels of parathyroid hormone (r = 0.67, p less than 0.01). No correlation was found between total parathyroid glandular weight or histopathological findings and clinical symptoms, serum levels of calcium, phosphate, alkaline phosphatases, calcium X phosphorus product or radiological evidence of bone disease. The enlargement of the glands was mostly uniform in the individual patient and all patients showed multiple gland involvement. This indicates that when parathyroid surgery is performed in patients with uraemia and secondary HPT, a radical approach, i.e. total parathyroidectomy with autotransplantation or subtotal parathyroidectomy, should always be used. In smaller glands only diffuse hyperplasia of parenchymal cells was generally found; fat cells were present in near-normal amounts. With increasing glandular weight, fat cells were more sparse and nodularity was common. In general, the proportion of oxyphil cells increased parallel with the total glandular weight, suggesting that this cell type is sensitive to stimulation. As a group, patients undergoing conservative renal treatment had suffered longer with renal disease, had larger parathyroid glands with more nodularity, and had more oxyphil cells than those undergoing parathyroidectomy while on haemodialysis.