3°HPT develops in some cases of long standing 2°HPT when prolonged hypocalcemia causes the development of independently functioning parathyroid glands. Hypercalcemia develops and again the PTH levels are significantly elevated. This situation occurs most commonly in patients with chronic renal failure. The classic situation occurs when a patient with kidney failure (and 2°HPT) receives a kidney transplant. The abnormal physiology that lead to 2°HPT is corrected with the transplant but the hyperplastic parathyroid glands continue to over-function. Treatment is usually surgical. Typically a standard neck exploration is performed and 3 and1/2 glands are resected. The cure rate approaches 98%. As with other cases of hyperplasia, re-operation may uncommonly be required in recurrent disease.
