A parathyroid biopsy is a procedure to remove a small piece of parathyroid gland.

The parathyroid glands are behind the thyroid gland at the top of the neck. They secrete parathyroid hormone (PTH), which helps control the body's calcium levels.

A parathyroid biopsy is done while the patient is awake. Using an ultrasound machine, the health care provider located the parathyroid gland of concern, and inserts a thin needle directly into the gland. The health care provider uses the need to remove a small piece of tissue from the gland. The tissue is sent to a laboratory, where it is examined under a microscope. The tissue's levels of parathyroid hormone will also be checked.

Tell your health care provider if you have any drug allergies or bleeding problems, or if you are pregnant. You must sign a consent form. Also, make sure the health care provider knows about all the medications you are taking.

The test feels like a quick shot (injection). You may feel a sting as the needle is inserted into the gland.

Parathyroid biopsy is most often performed to confirm the cause of hyperparathyroidism. It may also be done if an ultrasound exam shows a larger-than-normal parathyroid gland. Your doctor can only see a parathyroid gland on ultrasound if it is abnormally swollen.

The biopsy confirms that a parathyroid gland is enlarged, if hormone levels are too high, or if cells from the sample are abnormal.

• Parathyroid adenoma or carcinoma (rare)
• Parathyroid hyperplasia

Additional conditions under which the test may be performed:

• Multiple endocrine neoplasia I (MEN I)
• Multiple endocrine neoplasia II (MEN II)

You can return to normal activities the same day.