Multiglandular Parathyroid Hyperplasia Including Double Ectopic Glands: A Case Report

Hyperparathyroidism is a common cause of persistent hypercalcemia and is typically caused by a single parathyroid adenoma. Prompt treatment of hyperparathyroidism is essential to minimize impacts on various body systems such as the skeletal, renal, and cardiovascular systems. Hyperparathyroidism is typically cured by surgical removal of the adenoma, but persistent disease may occur in the presence of multiglandular hyperplasia or remaining adenoma. Further contributing to persistent disease are ectopic parathyroid glands. In this case a 51-year-old male was incidentally found to have hypercalcemia due to hyperparathyroidism. He was ultimately diagnosed with multiglandular parathyroid hyperplasia, with two of these glands in ectopic locations, one within the thyroid and the other in the mediastinum. Multiglandular disease and ectopic location contributed to need for reoperation and throughout the course of treatment, various imaging modalities were unsuccessful in locating hyperplastic parathyroid glands. This case demonstrates the importance of working up incidental hypercalcemia, persistence in treating hyperparathyroidism, and the need for use of various imaging modalities.