Diagnosis
If a person has any symptoms of parathyroid cancer, a doctor should conduct a physical examination and take their full medical history. During the physical exam, the doctor should thoroughly examine the neck and throat for any lumps or swelling. If the doctor suspects parathyroid cancer, he or she may recommend any of the following procedures to diagnose the disease:
Parathyroid Hormone Test
The doctor takes a blood sample and has it examined for high levels of parathyroid hormone (PTH). This condition, known as hyperparathyroidism, is almost always caused by benign parathyroid adenomas, and in some cases malignant parathyroid tumors.
Blood Chemistry Test
The doctor will check the level of calcium in the blood and look for any signs of hypercalcemia. Hypercalcemia is a condition in which there is too much calcium in the blood. The simultaneous elevation of both PTH and blood calcium is a strong indication that a parathyroid adenoma or parathyroid cancer may be present. The doctor may also check the levels of other substances such as blood urea nitrogen (BUN) and creatinine to monitor kidney function, which may be decreased as a result of hypercalcemia.
Sestamibi Scan
A sestamibi scan helps doctors locate an overactive parathyroid gland. A radioactive substance is injected into the patient's bloodstream and collects in the overactive gland. The overactive gland will be brightly illuminated on an imaging test that detects the radioactivity.
Venous Sampling
This test is rarely used and usually in centers with high experience. The doctor takes blood samples from veins near each of the four parathyroid glands and has them tested for PTH and other substances that may indicate parathyroid cancer. The doctor may perform this procedure if other tests are unable to find the hyperactive parathyroid gland.
CT of the neck
This radiographic test provides anatomic clarification of where the parathyroid tumor may be relative to other structures in the neck.
Ultrasound
Ultrasounds bounce sound waves off of internal organs in order to create echoes that form a picture. Ultrasounds may be able to help doctors locate some parathyroid tumors near the surface of the skin, but are generally not very effective in diagnosing this disease.
