Patient Education - Endocrine Encyclopedia
Endocrine Surgery Encyclopedia
Parathyroid hyperplasia involves enlargement of all four parathyroid glands, which are located
in the neck and control calcium metabolism. The condition produces high levels of calcium
in the blood (hypercalcemia).
Causes, incidence, and risk factors:
Parathyroid hyperplasia causes about 15% of cases of hyperparathyroidism, which leads to
elevated levels of calcium in the blood (hypercalcemia).
Parathyroid hyperplasia may occur sporadically (without a family history) or as part of
three familial (inherited) syndromes: multiple endocrine neoplasia 1 (MEN 1) and MEN 2A and
isolated familial hyperparathyroidism.
In the familial syndromes, a mutated gene is inherited in an autosomal dominant fashion
(you only need to get the gene from one parent to develop the condition).
In MEN 1, the problems in the parathyroids are associated with other tumors in the pituitary
and the pancreas. In MEN 2A, the overactivity of the parathyroids is associated with tumors
in the adrenal gland or thyroid.
The genetic basis of isolated familial parathyroidism is not yet clear.
Symptoms of hyperparathyroidism associated with parathyroid hyperplasia may include:
- myalgias (muscle pains)
- kidney stones
- bone fractures
Signs and tests:
Signs of hyperparathyroidism associated with parathyroid hyperplasia may include:
Tests may show:
- elevated serum calcium
- low serum phosphorus
- elevated intact PTH
- elevated serum chloride
- low serum bicarbonate
- elevated 24-hour urine calcium
- low bone mineral density
Surgery is the preferred treatment. Usually 3 1/2 glands are removed. The remaining tissue
may be implanted in the forearm to regulate calcium levels but allow easy surgical access
if hypercalcemia recurs.
The success rate for surgery for parathyroid hyperplasia is lower than that for parathyroid
adenoma. Persistent or recurrent hypercalcemia occurs about 20% of the time.
Advanced complications of hyperparathyroidism associated with parathyroid hyperplasia include
nephrocalcinosis and osteitis fibrosa cystica.
Patients may also have complications from the other endocrine tumors that are part of
the multiple endocrine neoplasia syndromes:
- MEN 1 -- includes pancreatic and pituitary tumors, adrenal adenomas and lipomas
- MEN 2A
-- includes medullary carcinoma of the thyroid and pheochromocytoma
Calling your health care provider:
Call your health care provider if you have any symptoms of hypercalcemia, or there is a family
history of any of the MEN syndromes
Patients with a family history of the MEN syndromes may be genetically screened for presence
of the defective gene and then screened regularly with standard diagnostic methods for endocrine
problems if this test is positive.
Review Date: 8/12/2004
Reviewed By: Aniket R. Sidhaye, M.D., Division of Endocrinology and Metabolism, Johns Hopkins
University School of Medicine, Baltimore, MD. Review provided by VeriMed Healthcare Network.
Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission
(www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M.
follows rigorous standards of quality and accountability. A.D.A.M. is among the first to
achieve this important distinction for online health information and services. Learn more
a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net
The information provided herein should not be used during any medical emergency or for
the diagnosis or treatment of any medical condition. A licensed medical professional should
be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for
all medical emergencies. Links to other sites are provided for information only -- they do
not constitute endorsements of those other sites. © 1997- 2007 A.D.A.M., Inc. Any duplication
or distribution of the information contained herein is strictly prohibited.