Diagnosis of Parathyroid Cancer

Diagnosis of Parathyroid Cancer

Parathyroid cancer may be hard to diagnose because the cells of a benign parathyroid adenoma and a malignant parathyroid cancer look alike. The patient’s symptoms, blood levels of calcium and parathyroid hormone, and characteristics of the tumor are also used to make a diagnosis. The following tests and procedures may be used:
  • Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
  • Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. To diagnose parathyroid cancer, the sample of blood is checked for its calcium level.
  • Parathyroid hormone test: A procedure in which a blood sample is checked to measure the amount of parathyroid hormone released into the blood by the parathyroid glands. A higher than normal amount of parathyroid hormone can be a sign of disease.
  • Sestamibi scan: A type of radionuclide scan used to find an overactive parathyroid gland. A small amount of a radioactive substance called technetium 99 is injected into a vein and travels through the bloodstream to the parathyroid gland. The radioactive substance will collect in the overactive gland and show up brightly on a special camera that detects radioactivity.
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.
  • Angiogram: A procedure to look at blood vessels and the flow of blood. A contrast dye is injected into the blood vessel. As the contrast dye moves through the blood vessel, x-rays are taken to see if there are any blockages.
  • Venous sampling: A procedure in which a sample of blood is taken from specific veins and checked to measure the amounts of certain substances released into the blood by nearby organs and tissues. If imaging tests do not show which parathyroid gland is overactive, blood samples may be taken from veins near each parathyroid gland to find which one is making too much PTH.
Factors Affecting Prognosis and Treatment Options The prognosis (chance of recovery) and treatment options depend on the following:
  • Whether the calcium level in the blood can be controlled.
  • The stage of the cancer.
  • Whether the tumor and the capsule around the tumor can be completely removed by surgery.
  • The patient’s general health.
 

Stages of Parathyroid Cancer

The process used to find out if cancer has spread to other parts of the body is called staging. The following imaging tests may be used to determine if cancer has spread to other parts of the body such as the lungs, liver, bone, heart, pancreas, or lymph nodes:
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
There are three ways that cancer spreads in the body. Cancer spreads in the body through tissue, blood or the lymph system. When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. There is no standard staging process for parathyroid cancer. Parathyroid cancer is described as either localized or metastatic:
  • Localized parathyroid cancer is found in a parathyroid gland and may have spread to nearby tissues.
  • Metastatic parathyroid cancer has spread to other parts of the body, such as the lungs, liver, bone, sac around the heart, pancreas, or lymph nodes.
 

Recurrent Parathyroid Cancer

Recurrent parathyroid cancer is cancer that has recurred (come back) after it has been treated. More than half of patients have a recurrence. The parathyroid cancer usually recurs between 2 and 5 years after the first surgery, but can recur up to 20 years later. It usually comes back in the tissues or lymph nodes of the neck. High blood calcium levels that appear after treatment may be the first sign of recurrence.