A<unk>  is a benign tumor of the parathyroid gland. It generally causes hyperparathyroidism; there are very few reports of<unk> s that were not associated with hyperparathyroidism. A human being usually has four parathyroid glands located on the posterior surface of the thyroid in the neck. In order to maintain calcium metabolism, the parathyroid glands secrete parathyroid hormone (PTH) which stimulates the bones to release calcium and the kidneys to reabsorb it from the urine into the blood, thereby increasing its serum level. The action of calcitonin opposes PTH. When a<unk>  causes hyperparathyroidism, more parathyroid hormone is secreted, causing the calcium concentration of the blood to rise, resulting in hypercalcemia.
Parathyroid adenoma
Parathyroid carcinoma
Thyroid adenoma
Pituitary adenoma
Adrenocortical adenoma
Primary hyperparathyroidism
Tertiary hyperparathyroidism
Nontoxic nodular goiter