Parathyroid Adenoma

Overview

What is a parathyroid adenoma?

An adenoma is a benign (noncancerous) growth that appears on one or more of your parathyroid glands.

An adenoma causes your parathyroid gland to make more parathyroid hormone than your body needs, a condition called primary hyperparathyroidism. Too much parathyroid hormone upsets your body’s normal calcium balance, which increases the amount of calcium in your bloodstream.

A similar but less common condition, called secondary hyperparathyroidism, can occur if you have chronic kidney failure.

What are parathyroid glands and what do they do?

Your parathyroid glands are located in your neck, around your thyroid gland. Most people have four pea-sized, oval-shaped parathyroid glands. The job of your parathyroid is to release parathyroid hormone, which helps manage how your body uses calcium.

Cells in your brain, heart, nerves, bones and digestive system all need calcium to function properly. “Communication” between your parathyroid and bloodstream helps keep calcium at its normal level. Parathyroid hormone takes calcium from your bone and increases reabsorption from your kidney and gut to maintain normal bloodstream levels.

Who develops parathyroid adenoma?

Approximately 100,000 Americans develop primary hyperparathyroidism each year. Women are three times more likely to develop parathyroid adenomas than men. Adenomas are most common in those 50 to 70 years old.

Symptoms and Causes

What are the symptoms of parathyroid adenoma?

Too much calcium in your blood (hypercalcemia) can cause a number of symptoms and medical conditions including:

You may not have, or recognize that you have, symptoms before they are discovered in routine blood work your healthcare provider may have ordered as a part of your general health care.

What causes a parathyroid adenoma to develop?

Scientists don’t know the cause of most parathyroid adenomas. About 10% are thought to be passed along through parents (inherited). Radiation exposure to your head and neck area as a child or young adult also may increase your risk of adenomas. Lack of enough calcium in your diet long-term is also thought to raise your risk.

Primary hyperparathyroidism is the medical condition that results from having adenomas. Hyperparathyroidism may be caused by one or more adenomas, four adenomas (a condition called hyperplasia), or cancer (which is very rare, less than 1% of all parathyroid cases).

A single parathyroid adenoma is the cause in up to 85% of cases, two adenomas cause 4% to 5% of cases and four adenomas cause 10% to 12% of hyperparathyroidism cases.

What are the complications of parathyroid adenoma if it’s not treated?

Untreated parathyroid adenomas cause a rise in calcium levels in your blood. An extremely high amount can cause:

  • Irregular heartbeats (cardiac arrhythmia).
  • Parathyroid crisis (a clinical event in which a person experiences mental changes that can lead to nervous system failure and coma).
  • Death.

Diagnosis and Tests

How are parathyroid adenomas diagnosed?

Parathyroid adenomas are usually discovered when a higher-than-normal calcium level shows up in a routine blood test. Your provider may also ask if you take thiazide diuretics or lithium. These two medications can raise the level of calcium in your blood. Your healthcare provider then confirms the diagnosis of primary hyperparathyroidism with a test that shows higher-than-normal parathyroid hormone levels in your blood.

It's important to understand that primary parathyroid disease is diagnosed by looking at the calcium and parathyroid hormone levels only. The fact that you may or may not have symptoms doesn’t matter in terms of making the diagnosis.

Once the diagnosis has been made, your healthcare provider may order more tests to gather more information and check for complications. These might include:

  • A special type of imaging method to determine if there are one or more adenomas.
  • A CT scan to check for calcium deposits in your kidney and urinary tract.
  • Bone densitometry to measure bone loss.
  • A 24-hour urine test to measure the amount of calcium lost in your urine.

Management and Treatment

How are parathyroid adenomas treated?

The most common treatment is surgery to remove the enlarged gland (or glands). Surgery cures the issue up to 95% of the time.

If you are too ill to have surgery, medication may be the only option. The different medications don’t reduce the extra amount of parathyroid hormone in the blood. Instead, they prevent the loss of calcium from bone. Hormone replacement therapy or other treatments for this condition must be taken for the rest of your life.

A prescription medication called cinacalcet (Sensipar®) reduces both calcium and parathyroid hormone levels in people with chronic kidney failure (secondary hyperparathyroidism). Its use in primary hyperparathyroidism is still being studied.

If I don't have symptoms, do I need surgery?

Surgery is the most common treatment for parathyroid adenoma, even if you don't have symptoms.

The removal of one or more of your parathyroid glands (parathyroidectomy) can make you feel better, improving the overall quality of your life. More importantly, parathyroidectomy can prevent osteoporosis and kidney stones.

If I decide to have surgery, what should I expect?

Several weeks before surgery, your surgeon will order tests to locate one or more overactive parathyroid gland(s). These tests may include:

  • An ultrasound of your neck.
  • A scan that uses a drug called Tc-sestamibi.

If imaging identifies a particular parathyroid gland that has an adenoma, your surgeon will look for that particular gland first during surgery. However, all four parathyroid glands need to be identified during the scan. This imaging is very important in terms of planning your surgery. Even if no parathyroid gland is seen on imaging, the diagnosis still remains and your surgeon would still recommend surgery.

What surgical steps are taken to remove parathyroid adenomas?

  1. A small incision is made in the front of your neck under general anesthesia.
  2. All four parathyroid glands are inspected during surgery. The surgeon takes out the abnormal parathyroid. If one or two abnormal parathyroid glands are found, they are removed and the remaining normal parathyroid gland can maintain a normal calcium level.
  3. If all four parathyroid glands are abnormal, then 3 1/2 of the glands are removed. Some parathyroid tissue needs to be left in your body to maintain normal calcium levels.
  4. Parathyroid hormone levels are checked during surgery. If the diseased parathyroid gland(s) have all been removed, the parathyroid hormone level should drop by at least 50%.

Parathyroid glands removed during surgery will be checked by a pathologist (frozen evaluation) for confirmation that the parathyroid gland was indeed hyperactive.

Finding all four parathyroid glands during the surgery provides the highest cure rate in the long term.

What are the risks of having surgery?

All surgeries have risks. With parathyroid surgery, you might experience:

  • Short-term or permanently low calcium levels in your blood (hypocalcemia). Symptoms of hypocalcemia include numbness/tingling in the fingers and around the mouth and muscle cramps.
  • If you have three or more parathyroid glands removed, you’ll definitely experience low calcium symptoms in the first week after surgery.

To reduce these risks:

Take calcium and vitamin D supplements for the first two weeks after surgery, in the amount and as often as instructed by your healthcare provider. If you’ve had 3 1/2 glands removed, you may be instructed to take an even higher dosage of calcium.

Prevention

Can parathyroid adenoma be prevented?

No, there’s no way to prevent the development of growths on your parathyroid glands.

Outlook / Prognosis

What should I expect following surgery to remove my parathyroid glands?

After surgery, your symptoms should stop within about one month. Surgery to remove the parathyroid glands or glands that have become overactive due to adenomas is highly successful. The cure rate is over 95%

The benefits of surgery to remove the diseased parathyroid glands include:

  • Higher bone density.
  • Lower risk of broken bones.
  • Reduced risk of kidney stones.

A note from Cleveland Clinic

Having parathyroid adenomas is a condition that may or may not have noticeable symptoms at first. Most of the time, your healthcare provider suspects that you have an adenoma after routine blood work shows you have an elevated calcium level. Even though you may not have symptoms, surgery is the recommended treatment for most people. Without surgery, high calcium levels in your blood can lead to other health problems, including kidney stones, osteoporosis and other symptoms that will affect the quality of your life long term. Surgery to remove the abnormal parathyroid glands cures primary hyperparathyroidism.

Last reviewed by a Cleveland Clinic medical professional on 04/06/2022.

References

  • American Academy of Family Physicians. Hyperparathyroidism. (https://familydoctor.org/condition/hyperparathyroidism/) Accessed 4/6/2002.
  • National Institute of Health. National Institute of Diabetes and Digestive and Kidney Diseases. Primary Hyperparathyroidism. (https://www.niddk.nih.gov/health-information/endocrine-diseases/primary-hyperparathyroidism) Accessed 4/6/2002.
  • Radiological Society of North American and the American College of Radiology. Parathyroid disease. (https://www.radiologyinfo.org/en/info/parathyroid-disease#:~:text=Your%20doctor%20may%20diagnose%20parathyroid,medication%2C%20dietary%20supplements%20and%20monitoring.) Accessed 4/6/2002.
  • Merck Manual Consumer Version. Hypercalcemia (High Levels of Calcium in the Blood). (https://www.merckmanuals.com/home/hormonal-and-metabolic-disorders/electrolyte-balance/hypercalcemia-high-level-of-calcium-in-the-blood?query=primary%20hyperparathyroidism) Accessed 4/6/2002.
  • Wolfe SA, Sharma S. Parathyroid Adenoma. (https://www.ncbi.nlm.nih.gov/books/NBK507870/) [Updated 2020 Jun 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-.
  • Potts, Jr JT, Juppner HW. Disorders of the Parathyroid Gland and Calcium Homeostasis. In: Jameson J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscaizo J, eds. Harrison’s Principles of Internal Medicine, 20e. McGraw-Hill; Accessed May 19, 2021.

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