DefinitionParathyroid cancer is a cancerous (malignant) growth in a parathyroid gland.Alternative NamesParathyroid carcinomaCauses, incidence, and risk factorsThe parathyroid glands are responsible for managing the calcium levels in the body. There are four parathyroid glands, two on top of each lobe of the thyroid gland. They are located at the base of the neck.Parathyroid cancer is an extremely rare type of cancer. Men and women are equally affected. It usually occurs in people older than 30.The cause of parathyroid cancer is unknown. People with multiple endocrine neoplasia type I have an increased risk for this disease. People who had head or neck radiation may also be at increased risk. Such radiation exposure, however, is more likely to cause thyroid cancer.SymptomsSymptoms of parath