ABSTRACT
Parathyroid carcinoma is an uncommon cause of PTH-related hypercalcemia with a reported incidence of 0.4% to 5% of all cases of primary hyperparathyroidism. Even though the clinical manifestations of hyperparathyroidism are more severe in patients with parathyroid carcinoma than in those with parathyroid adenoma, it is difficult to differentiate carcinoma from adenoma preoperatively. Parathyroid carcinomas are usually larger and firmer than parathyroid adenomas and patients with parathyroid carcinoma have a higher incidence of renal dysfunction, bone disease and gastrointestinal symptoms. Anemia is an uncommon clinical feature of parathyroid carcinoma. There have been no prior cases of ectopic parathyroid carcinomas reported to date. In this article, we report the case of a 26-year-old man who developed severe anemia and acute renal failure due to an ectopic parathyroid tumor and was diagnosed with parathyroid carcinoma postoperatively. His serum calcium levels returned to normal and the anemia resolved postoperatively.