Diagnosing and Treating Parathyroid Tumors
The parathyroid glands are typically four pea-sized glands located in the neck near the thyroid. They secrete parathyroid hormone (PTH), which regulates calcium levels throughout the body.
The parathyroid glands can grow in size and make more hormone than the body needs. These parathyroid adenomas grow very slowly, but produce too much PTH—a highly treatable condition known as hyperparathyroidism. Primary hyperparathyroidism means that an individual has overactive parathyroid disease. Secondary hyperparathyroidism results from a disorder in another organ such as the kidneys—or from a nutritional deficit – that causes the parathyroid glands to grow and produce more hormone without the rise in calcium levels in the blood. Tertiary hyperparathyroidism results from patients who have had secondary hyperparathyroidism but now have elevated levels of calcium as well.
Parathyroid tumors can be a form of multiple endocrine neoplasia type I. They are most often benign (not cancerous), but can be hereditary. Parathyroid cancer is fairly rare.
How are Parathyroid Tumors Diagnosed?
- Blood and urine tests: Tests to check for high levels of PTH and calcium in the blood and urine can help diagnose a parathyroid tumor.
- Symptoms: A patient's symptoms strongly indicate the presence of a parathyroid tumor. If symptoms persist after surgery, imaging tests can help verify a cancer.
- Imaging tests: Ultrasound is the first test of choice for evaluating patients with suspected hyperparathyroidism, and demonstrates the structure of both the thyroid and parathyroid gland. Ultrasound is highly operator-dependent; this means that the person performing the ultrasound needs to have expertise in performing this procedure. Scintigraphy, using either sestamibi alone or in combination with another isotope, allows for a two-dimensional image that can demonstrate abnormal over-function of one or more parathyroid glands. On occasion, our surgeons will use 4D CT scans using using injectable contrast material or venous sampling for PTH when other localization tests have failed.
- Biopsy: This is rarely performed. In this procedure, a fine needle aspiration biopsy is performed to remove cells to evaluate them under the microscope to determine if the tissue biopsied is parathyroid tissue or not. This procedure cannot tell us whether or not the gland biopsied is the abnormal gland.
Treating Parathyroid Tumors
Surgery is the primary treatment for parathyroid tumors and most patients with hyperparathyoridism—benign or cancerous. If cancer is found, the nearby thyroid gland and lymph nodes may also be removed.
When cancer has metastasized, additional methods and drugs are necessary to help the body excrete excess calcium.
At MedStar Washington Hospital Center, our endocrine surgeons perform minimally invasive parathyroidectomy with great success. In this surgery, the glands are examined and removed through small incisions using intraoperative parathyroid hormone measurements and pathologic real-time evaluation of the parathyroid glands to assess for cure. This is now used routinely by our surgeons to remove benign parathyroid tumors.