What is the parathyroid and parathyroid adenoma?
Parathyroid glands are located in your neck, next to the thyroid gland. Most people have four pea-sized, oval-shaped parathyroid glands. The job of the parathyroid is to secrete parathyroid hormone, which helps regulate how the body uses calcium.
Calcium is needed by cells in many parts of your body: the brain, heart, nerves, bones and digestive system. Parathyroid hormone takes calcium from bone, where it's stored, and releases it into the blood stream. "Communication" between the parathyroid and blood stream help keep calcium at its normal level.
Sometimes, benign (noncancerous) growths called adenomas appear on one or more of a person's parathyroid glands. We don’t know the cause of most parathyroid adenomas. About 10% are thought to be hereditary (inherited in a family). Radiation exposure to the head and neck area that the patient had as a child or an young adult also may increase the risk of adenomas. Parathyroid cancer is extremely rare and occurs in less than 1% of all parathyroid cases.
Adenomas cause the parathyroid gland to make more parathyroid hormone than the body needs, a condition called primary hyperparathyroidism. Too much parathyroid hormone upsets the body's normal calcium balance, which increases the amount of calcium in the blood stream.
A similar but less common condition, called secondary hyperparathyroidism, can occur in people with chronic kidney failure.
Who develops parathyroid adenoma?
Approximately 100,000 Americans develop primary hyperparathyroidism each year. Women are twice as likely to develop parathyroid adenomas as men, and often after menopause. Primary hyperparathyroidism may be caused by one adenoma, more than one adenoma (hyperplasia), or cancer (which is very rare).
Symptoms and Causes
What are the symptoms of parathyroid adenoma?
Too much calcium in the blood (hypercalcemia) can cause a number of symptoms and medical conditions. These include:
- Worsening memory and concentration.
- Depression, irritability or mental confusion.
- Kidney stones.
- Bone and joint pain, osteoporosis.
- Abdominal pain.
- General aches and pains from no obvious cause.
Many patients may believe they don't have any symptoms. However, when the calcium levels have been high for a number of years, patients may not be able to tell whether symptoms exist.
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, particularly in people without symptoms. Doctors then confirm the diagnosis of primary hyperparathyroidism with a test that shows parathyroid hormone levels in the blood are higher than normal.
It's important to understand primary parathyroid disease is diagnosed by looking at the calcium and parathyroid hormone levels only. Whether or not symptoms are there doesn't aid in the diagnosis.
Management and Treatment
How are parathyroid adenomas treated?
The most common treatment is to remove the enlarged gland (or glands). This surgery cures the problem up to 98% of the time.
In patient who 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 fight back by preventing 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 people with 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 for people who don't feel like they have any symptoms. For patients who have had high calcium levels for a number of years, it would be hard for them to tell if they are truly without symptoms.
Parathyroidectomy can make patients feel better, thus improving the overall quality of time. More importantly, parathyroidectomy can prevent osteoporosis and kidney stones.
If I decide to have surgery, what should I expect?
Several weeks before surgery, the surgeon will order tests to locate your one or more overactive parathyroid gland(s). These tests may include:
- An ultrasound of the neck.
- A scan that uses a drug called Tc-sestamibi.
If imaging can localize to one parathyroid gland, the surgeon will look for that particular gland first during surgery. However, all four parathyroid glands need to be identified during the procedure. This imaging is very important in terms of surgical planning. Even if no parathyroid gland showed up on imaging, the diagnosis is still there and the surgeon would still recommend surgery.
What happens during surgery to remove parathyroid nodules?
- A small incision is made in the front of the neck under general anesthesia.
- All 4 parathyroid glands are inspected during surgery. The surgeon takes out the abnormal parathyroid. If 1 or 2 abnormal parathyroid glands are found, they are removed and the remaining normal parathyroid gland can maintain normal calcium level.
- If all 4 parathyroid glands are abnormal, then 3½ of the glands are removed. Some parathyroid tissue needs to be left in the body to maintain normal calcium levels.
- Intraoperative parathyroid hormone levels are checked during surgery. If the diseased parathyroid gland(s) have all been removed, then the parathyroid hormone level before removal should drop at least 50% after removal.
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 surgery will provide the highest cure rate in the long term.
What are the risks of having surgery?
All surgeries have risks. With parathyroid surgery, some patients experience:
- Short-term or permanent low calcium levels in the blood (hypocalcemia). These can manifest as numbness/tingling in the fingers and around the mouth and muscle cramps.
- Patients who have 3 or more parathyroid glands removed will definitely experience low calcium symptoms in the first week after surgery.
To reduce these risks:
- All patients will be on calcium and vitamin D supplements for the first 2 weeks after surgery. A patient who had 3½ glands removed may be instructed to take even more calcium pills.