The parathyroid glands are located in the throat near the thyroid gland. They secrete parathyroid hormone (PTH), which helps control the body's calcium levels.

A parathyroid biopsy most often is performed as the first part of a surgical procedure to examine or remove these glands, usually because of hypercalcemia (increased blood calcium) caused by hyperparathyroidism (increased parathyroid hormone production).

Hyperparathyroidism can be a primary condition (parathyroid hyperplasia) or it can be a secondary condition caused by a tumor of the parathyroid gland.

For the biopsy, you will be under general anesthesia with endotracheal intubation (breathing tube placed in the airway). The physician will make an incision in the lower neck above the sternum. The thyroid gland is identified and may be rotated to enable the parathyroid glands to be located. The number and exact location of the parathyroid glands may vary from individual to individual. Usually, there are between three and seven, most commonly four.

A sample may be cut from the parathyroid glands, or an entire gland may be removed. The tissue is sent to the laboratory for examination.

You will be asked to fast before the biopsy. Fasting for 6 to 8 hours is recommended before any procedure using general anesthesia.

Infants and children:
The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

• Infant test/procedure preparation (birth to 1 year)
• Toddler test/procedure preparation (1 to 3 years)
• Preschooler test/procedure preparation (3 to 6 years)
• School-age test/procedure preparation (6 to 12 years)
• Adolescent test/procedure preparation (12 to 18 years)

After the surgery, you may feel some soreness around the neck incision. You may also have a slight sore throat caused by the breathing tube used during surgery.

This test is most often performed to confirm the cause of hyperparathyroidism.

This test is only performed when there is an abnormality of parathyroid function.

• 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)

Risks are those of general surgery:

• Reaction to anesthesia
• Excessive loss of blood
• Infection

Additional risks specific to this surgery include the following:

• Injury to the laryngeal nerve (the nerve to the vocal cords). This is extremely rare.
• Hematoma (blood collection under the skin)
• Breathing difficulty
• Hypocalcemia (low blood calcium) as a response to lack of parathyroid stimulation related to the surgery

It is possible that the doctor may not be able to locate the parathyroid glands during the procedure.