The simultaneous occurrence of primary hyperparathyroidism and hyperthyroidism due to Graves disease in the same patient is quite rare. Primary hyperpara-thyroidism accounts for hypercalcemia in only 1% of the thyrotoxic patients. The occurrence of hypercalcemia in thyrotoxic patients may represent a challenging diagnostic approach.
In this report, we describe the first case diagnosed in the Clinic of Endocrinology Timisoara with hyperthyroidism due to Graves disease and hypercalcemia due to PTH-secreting adenoma.
A 55-year-old woman was referred to our clinic for investigations. She had signs and symptoms of thyrotoxicosis and Graves ophtalmopathy. In routine laboratory investigations, hyperthyroidism and mild hypercalcemia were detected. Thyroid ultrasonography revealed a small goiter with hypoechoic parenchyma. Under thyrostatic therapy the patient became euthyroid. Further, laboratory determinations revealed maintaining of hypercalcemia and decrease of phosphoremia. Parathyroid hormone determination indicated high value. In ultrasonography, a small hypoechoic nodule was revealed in the lower posterior part of the right thyroid lobe, corresponding to right lower parathyroid gland. No complications of hyperparathyroidism were detected. The patient was operated, subtotal thyroidectomy and right inferior parathyroid adenoma removal being performed. Postoperatively, the total calcium and phosphorus returned to normal values and the clinical condition of this patient was very good.
Conclusion: The persistence of hypercalcemia in patients with Graves disease after achieving euthyroid status raises the suspicion of primary hyperparathyroidism. The high values of PTH confirm the coexistence of these two endocrine disorders, having probably no causal relationship. Thus, early diagnosis and surgical therapy of hyperparathyroidism, before occurrence of complications, confer a good evolution and prognosis for these cases.