PARATHYROIDS AND PARATHYROID ADENOMAS
Where is the parathyroid, and what does it do?
Parathyroid glands are very small endocrine glands located in the lower neck. Although the parathyroid glands locations may be quite variable in the neck in general they are located on or nearby the thyroid gland. Most people have four pea-sized, oval-shaped parathyroid glands. The parathyroid glands are endocrine glands that secrete hormones which are natural chemicals that regulate body functions. 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 the body—the brain, heart, nerves, bones, muscles and the digestive system. The levels of calcium in the each of the different tissues are very important to proper function and health. Parathyroid hormone (produced by the parathyroid glands) regulates the levels of calcium in the blood and other tissues. Depending on the levels of parathyroid hormone (PTH) calcium may be taken calcium from bone, where it is stored, and released into the blood stream. Parathyroid hormone also increases calcium absorption from the gut. The “Communication” between the parathyroid and the blood stream helps to keep calcium at its normal levels.
What is a parathyroid adenoma?
A parathyroid adenoma is a benign (noncancerous) growth which may appear on one or more of a person’s parathyroid glands. The cause of most parathyroid adenomas is unknown. However, about 10 percent are thought to be inherited or hereditary.
Although adenomas are benign tumors of the parathyroid glands. A parathyroid adenoma will cause the parathyroid gland to make more parathyroid hormone than the body needs. The excess parathyroid hormone (hyperparathyroidism) upsets the body’s normal calcium balance, which increases the amount of calcium in the blood stream.
Parathyroid adenomas are not rare. Approximately 100,000 Americans develop parathyroid adenomas each year. Hyperparathyroidism may be caused by one adenoma, more than one adenoma or parathyroid cancer (which is very rare).
How are parathyroid adenomas diagnosed?
Too much calcium in the blood (hypercalcemia) may not cause any symptoms at all or can cause a number of symptoms and medical conditions. Some of the problems which may be caused by a parathyroid adenoma include:
- Depression and or mental problems
- Bone and joint pain
- Abdominal pains
- General aches and pains from no obvious cause
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.
Patients with parathyroid cancer have symptoms including:
- Bone pain
- Kidney disease
- Extremely high levels of parathyroid hormone in the blood
- Neck masses that can be felt with the hand
Sometimes the diagnosis of cancer is difficult to make, even after surgery. This is because parathyroid carcer cells look very similar to noncancerous adenoma cells.
How are parathyroid adenomas treated?
The most common treatment is to remove the enlarged gland (or glands). This surgery cures the problem 95 percent of the time.
Instead of surgery, some people with mild or no symptoms of primary hyperparathyroidism may decide to try medication options. These and other treatments do not reduce the extra amount 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). However, its use in people with primary hyperparathyroidism (without kidney failure) is still being studied.
If I do not have symptoms, do I need surgery?
Surgery is the usual treatment for parathyroid adenomas, even for people who do not have obvious symptoms. Some people with only mild symptoms, such as feeling tired, forgetful, or depressed, may actually have another medical condition causing the symptoms. When primary hyperparathyroidism is the cause of symptoms, surgery can improve these symptoms and the person’s quality of life.
If you have hyperparathyroidism, a specific test (a bone density test)can show if the raised level of parathyroid hormone in your blood is causing serious calcium loss from your bones. Calcium loss can cause osteoporosis (thin bones) and increase the risk for breaking bones. X-rays of the kidney can show if you have kidney stones. The most common cause of kidney stones is too much calcium in your blood. These and other tests will help you and your doctor decide if surgery is appropriate for you.
If I decide to have surgery, what should I expect?
A procedure called minimally invasive parathyroidectomy has become widely accepted for removing enlarged parathyroid glands on one side of the neck. The benefits of this surgery include smaller incisions, shorter operations, and fewer complications compared with traditional two-side (bilateral) open-neck surgeries. In order to just focus on one area of the neck you doctor must of course know where the parathyroid adenoma is located.
How is the parathyroid adenoma located? How will it be determined which of my parathyroid glands has the adenoma?
Some of the tests which may be done to determine the location of a parathyroid adenoma include:
- A scan that uses a drug called Tc-sestamibi
- A 4-D CT scan of the neck and chest
- An ultrasound of the parathyroids
These presurgical imaging tests are quite accurate but not foolproof in determining the location of parathyroid adenoma. Your surgeon will plan the surgical approach based on how many adenomas are found and where they are located.
What happens during surgery to remove parathyroid nodules?
Minimally invasive surgery can be done if the patient has only one adenoma or two adenomas on the same side of the neck. Anesthesia is usually a general anesthetic where you are put completely asleep.
On the day of surgery your parathyroid hormone levels will drop dramatically within an hour after successful removal of the glands with adenomas. If parathyroid hormone levels do not drop after the targeted glands are removed, further surgery may be necessary to look for other adenomas.
What are the risks of having parathyroid surgery?
All surgeries have risks. With parathyroid surgery, some patients experience:
- Hoarseness from paralysis of the voice box (from damage to the voice box nerve
- Short-term or permanent low calcium levels in the blood (hypocalcemia)
To reduce these risks:
- A device can be used to monitor the nerve’s location during surgery.
- Hypocalcemia can be treated with calcium and special forms of vitamin D supplements.
- Careful control of bleeding during surgery can reduce the risk of developing blood clots in the neck.