Management problems in coexisting parathyroid crisis and florid thyrotoxicosis

The etiologic relationship between parathyroid and thyroid disease is controversial and still not well defined. An increased incidence of parathyroid adenomas with thyroid disease has been suggested by some researchers. Other authors are unable to confirm this and maintain that the major factor contributing to the coexistence of parathyroid adenomas and thyroid disease is the prevalence of these conditions, independently, in middle-aged women. Serum parathyroid hormone levels are generally lower in patients with thyrotoxicosis and higher in patients with hypothyroidism. The simultaneous occurrence of thyrotoxicosis and symptomatic hyperparathyroid crisis has been reported previously only once in the American literature. We report a case of a 32-year-old woman with documented uncontrolled Graves' disease (T4 = 20 micrograms/dl [normal = 4.5 to 11.5 micrograms/dl], total T3 = 361 ng/dl [normal = 115 to 190 ng/dl], T3RU = 53% [normal = 35% to 45%]), who developed parathyroid crisis (serum calcium = 15 mg/dl [normal = 9 to 11 mg/dl], N-terminal parathyroid hormone = 121 pg/ml [normal = 11 to 24 pg/ml], C-terminal parathyroid hormone = 9416 pg/ml [normal = 60 to 450 pg/ml]). After a turbulent 10-day period to achieve a euthyroid state with propranolol, propylthiouracil, and a saturated solution of potassium iodide, operation revealed a large parathyroid adenoma (2 by 2 by 3 cm) and a diffusely hyperplastic thyroid gland. Adenoma excision and bilateral subtotal thyroidectomy were performed. This case illustrates management guidelines of a true endocrine emergency in which prompt operation for acute hyperparathyroidism could not be undertaken until a euthyroid state and reduction in serum calcium levels were achieved with aggressive medical management.