A Case of Parathyroid Carcinoma Presenting Hyperparathyroidism that was Clinically Easy to Overlook

Parathyroid carcinoma is very rare in patients with primary hyperparathyroidism, only accounts for 1% to 2% of all cases. It is characterized by higher incidence of renal dysfunction, metabolic bone disease and gastrointestinal symptoms. Although the clinical manifestations of hyperparathyroidism are more severe in patients with parathyroid carcinoma when compared to those with those with parathyroid adenoma, it is difficult to differentiate carcinoma from adenoma without pathologic confirmation. To our knowledge, there have only been a few cases of hyperparathyroidism due to parathyroid carcinomas reported to date. Here, we report a case of 63-year-old woman developing osteoporosis, hypercalcemia and hypophosphatemia due to a parathyroid tumor and was diagnosed with parathyroid carcinoma postoperatively. [Korean Journal of Bone Metabolism, 19(1): 59-65, 2012]