What is parathyroid cancer?

Parathyroid cancer starts in the cells of the parathyroid glands. A cancerous (malignant) tumour is a group of cancer cells that can grow into and destroy nearby tissue. It can also spread (metastasize) to other parts of the body.

The parathyroid glands are 4 pea-sized organs behind the thyroid in the neck. They are usually attached to the surface of the thyroid with 2 on each side.

Diagram of the location of the parathyroid glands
Diagram of the location of the parathyroid glands

Parathyroid glands are part of the endocrine system. The endocrine system is the group of glands and cells that make and release hormones into the blood to control many body functions, such as breathing and circulating blood.

Parathyroid glands make parathyroid hormone (PTH). PTH controls the amount of calcium in the blood. Most calcium is stored in the bones. When calcium levels in the blood are low, the parathyroid glands make PTH to get the bones to release calcium into the blood. When calcium levels in the blood are high, the glands make less PTH.

Cells in any of the parathyroid glands sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous (benign) tumours called parathyroid adenomas. Cell changes can also lead to a non-cancerous condition called parathyroid hyperplasia.

But in some cases, changes to parathyroid cells can cause parathyroid cancer (also called parathyroid carcinoma). It is a very rare cancerous tumour.

Expert review and references

Parathyroid tumours and disease

Malignant tumours of the parathyroid gland are cancerous growths that have the potential to spread (metastasize) to other parts of the body. Parathyroid carcinoma is a rare, slow-growing (indolent) tumour.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

The Canadian Cancer Society is not responsible for the quality of the information or services provided by other organizations and mentioned on cancer.ca, nor do we endorse any service, product, treatment or therapy.


1-888-939-3333 | cancer.ca | © 2024 Canadian Cancer Society