Diagnosis of Parathyroid Cancer
Blood/urine tests. Many types of blood or urine tests may be done if a person has problems with their parathyroid. The most common test is a serum calcium test. Elevated serum calcium levels can suggest the presence of a parathyroid tumor or hyperplasia, which are overactive cells, on 1 or more glands. Another common laboratory test looks for elevated levels of the parathyroid hormone (PTH) and phosphorus levels in the blood. Doctors may suspect parathyroid cancer if these blood tests find a very high level of calcium and/or PTH.

Computed tomography (CT or CAT) scan. A CT scan creates a 2-dimensional picture of the inside of the body using x-rays taken from different angles. A computer combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan can be used to measure the tumor’s size. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill to swallow.

Sestamibi/SPECT scan. SPECT is a type of CT scan (see above), and it stands for "single proton emission computerized tomography." A sestamibi/SPECT scan is a procedure in which a specific protein, called sestamibi, is mixed with a radioactive material and injected into the patient’s vein. A parathyroid tumor will absorb the material, and the tumor will be visible on an x-ray of the neck. A sestamibi/SPECT scan may be recommended if laboratory tests show an elevated level of PTH or it may be used to evaluate parathyroid cancer that has spread to distant parts of the body or come back after treatment. See the Stages section for a full description of these stages.

Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. An ultrasound is very useful for locating a tumor in or around the thyroid gland. However, it has limitations if the tumor is located lower in the neck or upper chest.

Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. MRI can be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye can be injected into a patient’s vein or given as a pill to swallow.