Parathyroid Adenoma

What is a parathyroid adenoma?

Most people have four parathyroid glands, each about the size of a grain of rice, sitting behind the thyroid in the neck. They are separate from the thyroid and control blood calcium. When calcium falls, they release parathyroid hormone (PTH), which pulls calcium from bone, keeps it in the kidneys and boosts vitamin D to absorb more from food.

In a parathyroid adenoma, one gland grows and stops responding to the normal "off" signal of high calcium. It keeps releasing PTH, so calcium rises and stays high. This is primary hyperparathyroidism.

Parathyroid adenoma symptoms

Symptoms come from high calcium (hypercalcemia) and from calcium being drawn out of bones. The old memory aid is "stones, bones, groans and psychiatric moans".

Bones

• Thinning bones (osteoporosis), especially at the wrist and hip
• Fractures after minor falls
• Bone pain and joint aches
• Rarely, in severe long-standing disease, bone cysts (osteitis fibrosa cystica)

Kidneys

• Kidney stones, which affect up to about 1 in 5 people with the condition
• Thirst and passing a lot of urine, including at night
• Reduced kidney function over time

Gut ("groans")

• Constipation
• Nausea and poor appetite
• Heartburn and stomach ulcers
• Rarely, pancreatitis

Mind and mood ("moans")

• Fatigue and low energy
• Low mood, irritability or anxiety
• Poor concentration and memory ("brain fog")
• Poor sleep

Muscles and other

• Muscle weakness and aches
• High blood pressure
• Rarely, abnormal heart rhythms with very high calcium

Is sensitivity to pain a symptom?

Many people with primary hyperparathyroidism report generalized aches and pains, and some describe feeling more sensitive to pain. These usually improve after successful surgery. Diffuse aches are non-specific, though, so other causes should still be considered.

Parathyroid adenoma symptoms in females

The condition is about three times more common in women and peaks after menopause. Because falling estrogen also thins bones, women with an adenoma can lose bone faster than expected. Symptoms such as fatigue, low mood, poor sleep and joint aches overlap with menopause and are easy to attribute to it. A simple calcium blood test separates the two.

No symptoms at all

Many people today are diagnosed with "asymptomatic" disease after a routine blood test shows high calcium. On close questioning, a large share have subtle symptoms such as tiredness or poor concentration that they had put down to aging.

Causes and risk factors

Most adenomas arise for no known reason. Risk factors include:

• female sex and age over 50
• radiation to the head or neck, especially in childhood
• long-term lithium treatment
• inherited syndromes, especially multiple endocrine neoplasia type 1 (MEN1) and type 2A, familial hypocalciuric hypercalcemia (a mimic), and hyperparathyroidism-jaw tumor syndrome. These are more likely if the condition starts before age 30, runs in the family, or involves several glands.

How a parathyroid adenoma is diagnosed

Blood and urine tests

• Calcium: high (often adjusted for albumin).
• PTH: high or inappropriately "normal" despite high calcium. In a healthy person high calcium switches PTH off.
• Vitamin D: low vitamin D is common and is corrected because it affects results.
• Kidney function and a 24-hour urine calcium to rule out familial hypocalciuric hypercalcemia, which does not need surgery.

Checking for complications

• Bone density (DEXA) scan, including the forearm, which is most affected.
• Kidney imaging for stones or calcium deposits.

Finding the adenoma

Scans are done to plan surgery, not to make the diagnosis. The diagnosis is made by blood tests.

• Neck ultrasound
• Sestamibi scan: a nuclear scan where the overactive gland holds on to a tracer
• 4D CT scan or choline PET-CT when other scans are unclear

Parathyroid adenoma treatment

Surgery (parathyroidectomy)

Surgery is the only cure. When scans clearly show a single adenoma, a minimally invasive parathyroidectomy removes it through a small neck incision, often as a day case. Surgeons measure PTH during the operation, which should fall sharply within minutes once the right gland is out. Experienced surgeons cure about 95% to 98% of patients.

Surgery is recommended for anyone with symptoms, and for people without symptoms who meet any of these guideline criteria:

• calcium more than 1 mg/dL (0.25 mmol/L) above the upper limit of normal
• osteoporosis on a DEXA scan or a vertebral fracture
• reduced kidney function, kidney stones, or high urine calcium
• age under 50

Many surgeons now offer surgery to almost everyone fit for it, because it is low-risk and prevents long-term bone and kidney damage.

Risks are uncommon: temporary low calcium (tingling and cramps, treated with calcium tablets), hoarseness from irritation of the voice box nerve, and persistent disease if the adenoma is not found.

If surgery is not done

• Monitoring: calcium and kidney function every year and bone density every 1 to 2 years.
• Cinacalcet: a tablet that lowers calcium and PTH, used when surgery is not possible.
• Bisphosphonates or denosumab: protect the bones but do not lower calcium much.
• Day-to-day: drink plenty of fluids, keep a normal calcium intake (do not restrict it), keep vitamin D adequate, and avoid thiazide diuretics and lithium if possible.

Outlook after surgery

After successful surgery calcium returns to normal within a day or two. Bone density improves over the following 1 to 2 years, the risk of new kidney stones falls, and many people notice better energy, mood and sleep. Calcium is checked again around 6 months and then periodically, because a small number of people develop a new adenoma later.

Frequently asked questions

What are the most common parathyroid adenoma symptoms?

Fatigue, aches and pains, low mood, poor concentration, thirst, frequent urination, constipation and kidney stones are the most common. Many people also have thinning bones. Some have no obvious symptoms, and the adenoma is found after a routine blood test shows high calcium.

Is a parathyroid adenoma cancer?

No. A parathyroid adenoma is benign and does not spread. Parathyroid cancer is a different and rare condition, causing well under 1% of primary hyperparathyroidism, usually with very high calcium and a large, hard neck lump.

Can a parathyroid adenoma be treated without surgery?

Surgery is the only cure. If surgery is not suitable, medicines such as cinacalcet lower calcium, and bone-protecting drugs reduce fracture risk, with regular monitoring. People with mild disease and no complications may choose monitoring after discussing it with their endocrinologist.

Can you feel a parathyroid adenoma in your neck?

Almost never. Most adenomas are about 1 to 2 cm and lie behind the thyroid, too deep to feel. A lump you can feel in the neck is much more likely to be a thyroid nodule. A large, hard, palpable parathyroid mass raises concern for parathyroid cancer.

How long does it take to feel better after parathyroid surgery?

Calcium normalizes within 1 to 2 days. Many people notice improved energy, sleep and mood within weeks, though it can take several months. Bone density keeps improving for 1 to 2 years. Tingling in the days after surgery means calcium has dipped and should be reported.