Parathyroid

There are four parathyroid glands along the behind the thyroid glands and near the edges of the gland. They are pea-sized and control calcium levels in the body. The most common disease of the parathyroid glands in children is hyperpararthyroidism.

Neonatal Hyperparathyroidism

This rare disease causes high levels of calcium during the neonatal period. This can occasionally run in families. Symptoms can develop over days to months after birth and include lethargy, decreased body tone, dehydration, and feeding problems. Treatment involves removal of the four glands with transplantation of one gland into the muscles of the neck or arm.

Familial Hyperparathyroidism

This disease affects all four glands. This often is part of a syndrome, MEN I, MEN IIA, and familial hypocalciuric hypercalcemia. Children are diagnosed as part of the screening of the entire family. If not diagnosed by screening of a family, these children can present with lethargy, malaise, and renal stones.

All children with MEN I (multiple endocrine neoplasia) have abnormalities of the parathyroid glands. They also can have pancreatic and pituitary tumors. Hyperparathyroidism from MEN I is usually treated by removal of all four glands. Some surgeons recommend leaving a small piece in place while others recommend transplanting one gland into the muscles of the neck or arm. The parathyroid tissue left behind occasionally can grow and cause symptoms to return. During the surgery, some also recommend removal of the thymus gland. This is a fatty tissue behind the sternum which is involved in the immune system in infancy and later involutes (goes away). In MEN I, the thymus can have additional parathyroid tissue (spernumerary glands) and can cause recurrent symptoms if not removed along with the four parathyroid glands. After the operation, 5-10% of children will require lifelong medications for hypopararthyroidsim.

Children with MEN IIA have tumors of the thyroid (medullary thyroid carcinoma) and adrenal glands (pheochromocytoma) in addition to the parathyroid disease. Because all patients with MEN IIA develop MCT, total thyroidectomy is recommended by age 5 years. If the child has hyperparathyroidism, the parathyroid resection can be done at the time of the thyroidectomy. The four parathyroid glands are all examined, and the enlarged glands (usually 1 or 2 glands) are removed. If more glands are removed, there is an increased risk of hypoparathyroidism. MEN IIB is not associated with hyperpararthyroidism.

Parathyroid Adenoma

An adenoma is a non-cancerous enlargement of the parathyroid gland which causes problems from increased calcium levels in the blood. It is more common in boys, and is the most common cause of hyperpararthyroidism during adolescence. Symptoms in children include kidney stones, high blood pressure, headaches, constipation, weakness, and fatigue. Hperparathyroidism can cause pancreatitis. Children are initially evaluated by ultrasound looking for an enlarged gland. This is followed by technetium-99m sestamibi radionuclide study to help determine which of the four parathyroid glands has increased activity. If both studies identify a single involved gland, a small incision over the gland can be made to remove just the identified gland. If the two studies do not indicate a single gland involved, a larger incision is made and all four glands must be identified and biopsied. All glands with an adenoma should be removed. If hyperplasia of the glands is demonstrated instead of an adenoma, three and half glands are removed with the remaining portion of a gland implanted into the muscles of the neck or arm.

Secondary Hyperparathyroidism

If a child is on long-term dialysis for renal failure, they can develop increased parathyroid function called secondary (to renal failure) hyperpararthyroidism. While on dialysis, attempts are made to keep phosphorous absorption low. Despite this, children can rarely develop bone pain and pruritis (itching). Blood work confirms the diagnosis in these patients. If medical management fails, the patient will need surgery with visualization of all four glands. One normal appearing gland can be preserved. If all look abnormal, a portion of one gland should be implanted into the muscles of the neck or arm.

Tertiary Hyperparathyroidism

This usually occurs after kidney transplantation. The parathyroid glands continue to have increased function despite high calcium levels (which should suppress thyroid function). These patients require removal of all four parathyroid glands with a portion of one gland implanted into the muscles of the neck or arm.