ConditionCancer
Parathyroid Cancer
Parathyroid cancer is a rare cancer of one of the four parathyroid glands in the neck, responsible for fewer than 1 percent of cases of primary hyperparathyroidism. Most tumors make large amounts of parathyroid hormone (PTH), causing very high blood calcium with bone pain, kidney stones, thirst, nausea and weakness, and sometimes a lump in the neck. The main treatment is complete surgical removal with the nearby thyroid lobe. It grows slowly, and many people live for years, but it often recurs.
Also called: Parathyroid carcinoma, cancer of the parathyroid gland
At a glance
- What it is
- A rare malignant tumor of a parathyroid gland.
- Main effect
- Very high PTH and calcium, often much higher than with benign adenomas.
- Symptoms
- Bone pain, fractures, kidney stones, thirst, nausea, confusion, a neck lump, hoarseness.
- Risk factors
- Hyperparathyroidism-jaw tumor syndrome (CDC73 gene), radiation to the neck, long-standing kidney disease (rare).
- Treatment
- Complete en bloc surgery; calcium-lowering medicines; radiation or other therapies for recurrence.
- Outlook
- Often slow-growing; 5-year survival above 75 to 85 percent, but recurrence is common.
When to get help
Call 911 or go to the ER
- Confusion, extreme drowsiness, severe vomiting, dehydration or an irregular heartbeat with known high calcium (possible hypercalcemic crisis)
See a doctor within a day or two
- Blood calcium above about 14 mg/dL (3.5 mmol/L), or rapidly rising calcium
- A hard, growing lump in the neck with hoarseness or difficulty swallowing
- Severe bone pain or a fracture after minor injury
Book a routine appointment
- High calcium and PTH found on blood tests, especially if very high
- A family history of hyperparathyroidism or jaw tumors
- Persistent or returning high calcium after parathyroid surgery
What parathyroid cancer is
The parathyroid glands control calcium by releasing PTH. When they overproduce it, the result is hyperparathyroidism. Almost all overactive parathyroid glands are benign: a single adenoma or enlargement of all four glands. In parathyroid cancer, a gland becomes malignant, can invade surrounding tissues such as the thyroid, muscles and nerves, and can spread to lymph nodes, lungs, bones and liver.
It is very rare, with only a few hundred cases diagnosed in the US each year, usually in people aged 40 to 60, affecting men and women about equally.
Risk factors
- Hyperparathyroidism-jaw tumor syndrome: an inherited condition caused by changes in the CDC73 (HRPT2) gene; up to about 15 percent develop parathyroid cancer
- familial isolated hyperparathyroidism
- radiation exposure to the neck
- rarely, long-standing secondary hyperparathyroidism from kidney failure
- a minority of people with sporadic parathyroid cancer have CDC73 changes, so genetic testing is often offered
Symptoms
Symptoms come mainly from very high calcium (hypercalcemia):
- bone pain, thinning bones and fractures
- kidney stones and kidney damage
- excessive thirst and urination
- nausea, vomiting, loss of appetite and constipation
- tiredness, weakness and muscle aches
- depression, confusion and memory problems
- pancreatitis or peptic ulcers
Local symptoms:
- a lump in the neck, felt in up to about half of people
- hoarseness from invasion of the voice box nerve
- difficulty swallowing
A small number of parathyroid cancers do not produce hormone; they present as a neck mass without high calcium.
Parathyroid cancer vs adenoma
| Feature | Parathyroid adenoma | Parathyroid cancer |
|---|---|---|
| Calcium | Mildly raised | Often very high (above 14 mg/dL) |
| PTH | Moderately raised | Often several times the upper limit |
| Neck lump | Rarely felt | Often felt, hard |
| Symptoms | Often none | Usually severe bone and kidney disease together |
| Size | Usually under 2 cm | Often over 3 cm |
| Behavior | Stays in the gland | Invades nearby tissue, can spread |
Diagnosis
Parathyroid cancer is difficult to diagnose before surgery. Suspicion is raised by:
- very high calcium and PTH
- a palpable neck mass or vocal cord paralysis
- ultrasound showing a large, irregular gland with invasion
- CT, MRI, sestamibi or PET scans to locate the tumor and look for spread
Fine-needle biopsy is avoided, because it can spread cancer cells along the needle track. The diagnosis is usually confirmed by examining the removed tumor, looking for invasion into blood vessels, nerves or surrounding tissue.
Treatment
Surgery
The best chance of cure is complete removal at the first operation: the tumor is removed in one piece (en bloc) along with the thyroid lobe on the same side and any involved tissue, taking care not to rupture it. Lymph nodes may be removed if they are involved. Surgery for recurrent disease or metastases can also control calcium.
Controlling calcium
- IV fluids for dehydration
- cinacalcet or other calcimimetics to lower PTH and calcium
- bisphosphonates or denosumab to reduce bone breakdown
- treating hypercalcemic crises in hospital
Other treatments
- radiation therapy may be used after surgery in selected cases or for local recurrence
- chemotherapy has limited effect
- targeted therapies and immunotherapy are being studied in clinical trials
Follow-up and outlook
Regular calcium and PTH tests are the best way to detect recurrence, along with imaging when levels rise. Recurrence is common, often within 2 to 5 years, but can occur much later. Because the cancer grows slowly, 5-year survival is generally reported above 75 to 85 percent and 10-year survival around 50 to 70 percent. Death is most often due to uncontrolled high calcium rather than tumor bulk, so calcium control is central to care.
Frequently asked questions
What are the symptoms of parathyroid cancer?
Most symptoms come from very high calcium: bone pain and fractures, kidney stones, thirst, frequent urination, nausea, constipation, tiredness, depression and confusion. Some people have a hard lump in the neck or hoarseness.
How is parathyroid cancer different from a parathyroid adenoma?
Adenomas are benign and usually cause mild calcium elevation. Parathyroid cancer typically causes much higher calcium and PTH, a larger and harder gland, and may invade surrounding tissue or spread. The final diagnosis is made after the tumor is removed.
What is the survival rate for parathyroid cancer?
Parathyroid cancer usually grows slowly. Five-year survival is generally above 75 to 85 percent and 10-year survival around 50 to 70 percent, depending on whether the tumor was completely removed and whether it has spread.
Is parathyroid cancer hereditary?
Some cases are linked to inherited conditions, particularly hyperparathyroidism-jaw tumor syndrome caused by CDC73 gene changes. Genetic testing is often recommended for people with parathyroid cancer, and family members may be offered screening.
Sources
This guide was written from current patient and clinical guidance, including:
- National Cancer Institute: Parathyroid Cancer Treatment (PDQ)
- American Association of Endocrine Surgeons: Guidelines for Definitive Management of Primary Hyperparathyroidism
- MedlinePlus Genetics: Hyperparathyroidism-jaw tumor syndrome
- American Cancer Society: Parathyroid Cancer
- NCCN Guidelines: Neuroendocrine and Adrenal Tumors (parathyroid section)