What is a Benign Notochordal Cell Tumour (BNCT)?

A Benign Notochordal Cell Tumour, or a “BNCT”, is a non-cancerous growth that arises in the bones of the spine. The same growth has been called different names over the years, including notochordal rest or vertebral notochordal rest, but the official terminology is now Benign Notochordal Cell Tumour. Doctors may shorten this to BNCT or still use the other names.

BNCTs are related to the rare bone tumour, chordoma, but BNCTs are thought to be benign. Both children and adults can have a BNCT. They can occur in any of the spinal bones, from the bottom of the skull down to the tail bone, or coccyx.

BNCTs can occur at the base of the skull and throughout the spine to the tail bone or coccyx (shown by pink dots).

Frequently asked BNCT questions

It is not known exactly how many people have a BNCT but up to 1 in 5 people may have a one. Some of these are very small though (a few millimetres across) and may not cause any symptoms or show up on a scan.

BNCTs are often discovered when people have a scan of their spine for another reason, such as another spine condition. This is because they do not always cause symptoms or cause mild symptoms such as back ache. BNCTs are mostly seen on magnetic resonance imaging, or MRI, within the bones of the spine.

This is not entirely clear at the moment. The cells in a BNCT look like the cells from a structure in the fetus called a notochord. This structure gives rise to the spine in a baby before shrinking away as the spine develops. In BNCTs it is thought that the cells from the notochord persist beyond birth and grow during life - the reason why this happens is the subject of ongoing research.

If a BNCT is small, which they often are, some patients undergo a period of observation using regular scans. Others may be scanned for an observation period to ensure the BNCT is not growing before stopping the scans. Depending on how the BNCT looks on the scan, some doctors may recommend a biopsy. This is a sample of the growth is taken using a needle so that the tissue can be looked at under the microscope. This can help to confirm the diagnosis but may not always be necessary.

If treatment is thought to be necessary, which is not very common, it may consist of surgery and/or other treatments like proton beam therapy.

If a BNCT changes over time or causes symptoms, then other treatment options may be discussed, for example surgery to remove it. The majority of BNCTs can be safely observed rather than treated surgery but this decision is made on an individual basis.

No. BNCTs are non-cancerous and the majority do not cause any problems. It is possible that a BNCT can grow into a chordoma but this would only happen in a very small percentage. To put this in perspective, you are more likely to be killed in a motor vehicle accident in this country than to have a BNCT that becomes a chordoma. Furthermore, if a BNCT is monitored with scans, any change will be detected early and this allows the best treatment if it is required.

At the moment there is little information for patients about BNCTs which is why we created this page. With more research being done into this condition, there will be more information. We will therefore update this leaflet as more information becomes available. If you have any comments about this leaflet, please do get in touch with us so we can improve it.
Contact: Dr Inga Usher inga.usher@nhs.net

Yes, if you have a BNCT and would like to join a study, contact Dr Inga Usher on the address above. We are running a study into the genetics of BNCTs to better understand what causes them and how they are related to chordomas.

This information is provided for general guidance only and is not intended to be a substitute for specialist and professional medical advice, diagnosis or treatment. It is crucial to seek the advice of your GP, oncologist or other medical specialist with any questions you may have regarding your concerns and/or medical care. Contact us to find out more.

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