Parathyroid adenoma

Definition

A parathyroid adenoma is a noncancerous (benign) tumor of the parathyroid glands. The parathyroid glands are located in the neck, near or attached to the back side of the thyroid gland.

Alternative Names

Hyperparathyroidism - parathyroid adenoma; Overactive parathyroid gland - parathyroid adenoma

Causes

The parathyroid glands in the neck help control calcium use and removal by the body. They do this by producing parathyroid hormone, or PTH. PTH helps control calcium, phosphorus, and vitamin D levels in the blood and is important for healthy bones.

Parathyroid adenomas are common. Most parathyroid adenomas do not have an identified cause. Sometimes a genetic problem is the cause. This is more common if the diagnosis is made when you are young.

Conditions that stimulate the parathyroid glands to get bigger can also cause an adenoma. These include:

• Genetic disorders
• Taking the drug lithium
• Chronic kidney disease

Women over age 60 have the highest risk for developing this condition. Radiation to the head or neck also increases the risk.

Symptoms

Many people have no symptoms. The condition is often discovered when blood tests are done for another medical reason.

Parathyroid adenomas are the most common cause of hyperparathyroidism (overactive parathyroid glands), which leads to an increased blood calcium level. Symptoms may include any of the following:

• Confusion
• Constipation
• Lack of energy (lethargy)
• Muscle pain
• Nausea or decreased appetite
• Urinating more often at night
• Weak bones or fractures

Exams and Tests

Blood tests may be done to check levels of:

• PTH
• Calcium
• Phosphorus
• Vitamin D

A 24-hour urine test may be done to check for increased calcium in the urine.

Other tests include:

• Bone density exam
• Kidney ultrasound or CT scan (may show kidney stones or calcification)
• Kidney x-rays (may show kidney stones)
• MRI
• Neck ultrasound
• Sestamibi neck scan (to identify the location of the parathyroid adenoma)

Treatment

Surgery is the most common treatment, and it often cures the condition. But, some people choose to only have regular checkups with their health care provider if the condition is mild.

To help improve the condition, your provider may ask you to stop taking calcium and vitamin D supplements. Women who have gone through menopause may want to discuss treatment with estrogen.

Outlook (Prognosis)

When treated, outlook is generally good.

Possible Complications

Osteoporosis and the increased risk for bone fractures is the most common concern.

Other complications are less common, but may include:

• Nephrocalcinosis (calcium deposits in the kidneys that can reduce kidney function)
• Osteitis fibrosa cystica (softened, weak areas in the bones)

Complications from surgery include:

• Damage to a nerve that controls your voice
• Damage to the parathyroid glands, which causes hypoparathyroidism (lack of enough parathyroid hormone) and low calcium level

When to Contact a Medical Professional

Call your provider if you have symptoms of this condition.

Images

References

Reid LM, Kamani D, Randolph GW. Management of parathyroid disorders. In: Flint PW, Francis HW, Haughey BH, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 123.

Silverberg SJ, Bilezikian JP. Primary hyperparathyroidism. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 63.

Thakker RV. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 232.