Hyperparathyroidism and parathyroid carcinoma.

A patient with hyperparathyroidism due to a functioning parathyroid carcinoma presented with distinctive clinical and laboratory features, including high serum calcium levels, roentgenographic signs of severe bone disease, a markedly elevated alkaline phosphatase level, a palpable cervical mass, and a high parathyroid hormone level. Treatment of parathyroid carcinoma requires en bloc resection of the ipsilateral thyroid lobe and isthmus for the primary tumor and ispilateral neck dissection for metastatic disease. Because the tumor grows slowly, recurrences should be resected to provide relief of hypercalcemia, the usual cause of death.