Parathyroid hyperplasia

Definition

Parathyroid hyperplasia is the enlargement of all four parathyroid glands. The parathyroid glands are glands in the neck that produce parathyroid hormone (PTH).

Causes

Parathyroid hyperplasia may occur in people without a family history of the disease, or as part of three inherited syndromes:

• Multiple endocrine neoplasia I (MEN I)
• MEN IIA
• Isolated familial hyperparathyroidism

In people with an inherited syndrome, a changed (mutated) gene is passed down through the family. You only need to get the gene from one parent to develop the condition.

• In MEN I, problems in the parathyroid glands are due to tumors in the pituitary gland and pancreas.
• In MEN IIA, overactivity of the parathyroid glands is due to tumors in the adrenal or thyroid gland.

Symptoms

Symptoms may include:

• Bone fractures
• Constipation
• Lethargy
• Muscle pain
• Nausea

Exams and Tests

Blood tests will be done to check calcium, phosphorus, magnesium, PTH, and vitamin D levels. A 24-hour urine test may be done to determine how much calcium is being removed from the body and is leaking into the urine.

Bone x-rays and a bone density test (DXA) can help detect fractures, bone loss, and bone softening.

Treatment

Surgery is the preferred treatment. Usually 3 1/2 glands are removed. The remaining tissue may be implanted in the forearm so a doctor can easily operate on it if symptoms come back. This tissue will also help the body control calcium levels.

Outlook (Prognosis)

Increased calcium levels persist or return about 20% of the time after surgery.

Possible Complications

Parathyroid hyperplasia can cause hyperparathyroidism, which leads to an increase in blood calcium levels.

Complications include increased calcium in the kidneys and osteitis fibrosa cystica (a softened, weak area in the bones).

Patients may also have complications from the other tumors that are part of the multiple endocrine neoplasia syndromes. See also:

• MEN I
• MEN IIA

When to Contact a Medical Professional

Call your health care provider if:

• You have any symptoms of hypercalcemia
• You have a family history of a MEN syndrome

Prevention

Patients with a family history of the MEN syndromes may want to have genetic screening to check for the defective gene. Those who have the defective gene may have routine screening tests to detect any early symptoms.

References

Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Kronenberg HM, Schlomo M, Polansky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. St. Louis, Mo: WB Saunders; 2008:chap. 266.

Bringhurst FR, Demay MB, Kronenberg HM. Disorders of mineral metabolism. In: Kronenberg HM, Schlomo M, Polansky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. St. Louis, Mo: WB Saunders; 2008:chap. 27.

Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 253.

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