Development of parathyroid hyperplasia or adenomas and autonomous parathyroid hormone (PTH) secretion following chronically low calcium levels.
Any cause of chronic secondary hyperparathyroidism, in particular chronic renal failure. Often becomes apparent postrenal transplantation.
During secondary hyperparathyroidism, the glands may become autonomous, either developing an adenoma or hyperplasia which secretes excessive PTH resulting in hypercalcaemia. In a patient with renal failure and secondary hyperparathyroidism who undergoes renal transplantation, PTH secretion may fall as the glands recover normal activity.
History of previous secondary hyperparathyroidism. Clinical features are those of hypercalcaemia (bones, stones, groans and moans).
Acute severe hypercalcaemia may cause seizures, abdominal pain, nausea and vomiting, confusion and pyschosis.
Hypercalcaemia with markedly raised PTH.
Total parathyroidectomy possibly with autotransplantation of parathyroid tissue equivalent to a normal gland into the arm, where it can be readily accessed for further treatment. Calcium replacement, phosphate binders and alfacalcidol (1-alpha hydroxyvitamin D3) to increase calcium absorption and serum levels may be effective by negative feedback on the parathyroids.