Parathyroid Carcinoma, from the CureRays guide library.

Parathyroid carcinoma is a very rare cancer of one of the tiny neck glands that control calcium — most of its harm comes from sky-high calcium levels, and the best chance of cure is complete removal in one careful operation.

What it is.

Parathyroid carcinoma is a very rare cancer of the parathyroid glands — four tiny glands behind the thyroid in the neck that make parathyroid hormone (PTH), which controls the level of calcium in the blood. Almost all parathyroid carcinomas are 'functioning,' meaning they pour out PTH and drive blood calcium to dangerously high levels. Most of the symptoms — kidney stones, bone pain and fractures, fatigue, confusion, and stomach upset — come from this severe high calcium rather than from the tumor pressing on anything. Because the cancer grows slowly but the high calcium can be life-threatening, controlling calcium is an urgent priority alongside treating the tumor itself. The single most important treatment is a complete surgical removal of the tumor together with the surrounding tissue in one piece (en-bloc resection) during the first operation, because that offers the best chance of cure and recurrences are hard to clear later. Some cases are linked to an inherited condition called hyperparathyroidism-jaw tumor syndrome, tied to the CDC73 (HRPT2) gene.

How radiation treats it.

Radiation damages the DNA inside cancer cells so they can no longer divide and survive, while normal cells are better at repairing themselves. For parathyroid carcinoma, surgery is the main cure, and radiation is used in a supporting role — given to the neck after surgery to lower the chance the cancer comes back when it was invasive or incompletely removed, or to ease symptoms from disease that has spread. It is delivered as short, painless daily sessions and leaves no radioactivity in your body, so you remain safe to be around family and children.

The ways we can treat it.

Surgery. The primary and only reliably curative treatment — a complete, in-one-piece removal at the first operation, with re-operation used for recurrences.

Adjuvant radiation. External-beam radiation to the neck after surgery can lower the chance of local recurrence when the tumor was invasive, incompletely removed, or involved lymph nodes.

Palliative radiation. Targeted radiation can relieve pain from bone deposits or control a specific area of recurrent disease that cannot be removed surgically.

Questions we hear often.

Why is the high calcium such a big deal? Most parathyroid carcinomas pour out parathyroid hormone, which drives blood calcium very high. That high calcium — not the tumor pressing on something — causes most of the symptoms (kidney stones, bone pain, fatigue, confusion) and can be life-threatening, so controlling it is just as urgent as treating the tumor.

Why does the first surgery matter so much? The best chance of cure comes from removing the tumor completely, in one piece, with the surrounding tissue, at the very first operation. If the tumor is broken into or only partly removed, cancer cells can be left behind that are very hard to clear later, which is why this surgery is best done by an experienced endocrine surgeon.

Should I be tested for an inherited cause? Sometimes. A minority of parathyroid carcinomas are linked to an inherited condition (hyperparathyroidism-jaw tumor syndrome, tied to the CDC73 gene). Your team may recommend genetic counseling, especially if you are young or have a family history, so relatives can be screened if needed.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.