Content overview

What is it?

How does it present?

How is it diagnosed?

How can it be treated?

Support measures

What is it? 

Anaplastic thyroid cancer is a rare, aggressive cancer of the thyroid which is more common in older people. Please note poorly differentiated thyroid tumours are different and it is important to distinguish them (whenever possible).

How does it present?

It often presents as a rapidly enlarging mass in the neck.  Sometimes it can be associated with a new, hoarse voice, or difficulty with breathing or swallowing. The assessment and diagnosis should be as fast as possible with early biopsies taken of the tumour sent for analysis, including BRAF mutation testing. This genetic test looks for specific changes (mutations) in the BRAF gene and many thyroid cancer centres in the UK can undertake a rapid turnaround testing for BRAF mutation. Testing for other genes that may help with treatmentwill take longer to be processed in the lab.

How is it diagnosed?

The tumour is usually diagnosed by one or more biopsies. A CT scan or MRI scan of the neck can often show if the tumour has spread to other tissues in the neck, e.g. oesophagus, trachea, large vessels in the neck. A CT scan of the body will show whether the disease has spread to the lungs or other parts of the body. 

How can it be treated?

Unfortunately, treatment of this disease is very difficult and often not very effective. Surgery is rarely a treatment option because by the time it is diagnosed the tumour is usually too advanced and has spread into important areas of the neck.

If the tumour is BRAF mutation positive then there are targeted drugs that can be considered to be used (e.g. Dabrafenib and Trametinib.)   

Sometimes radiotherapy (with or without chemotherapy) is advised.

Specialist oncologists and surgeons will discuss the advantages and disadvantages of these treatments and whether they may be options in your case.

Support measures

Anaplastic cancer of the thyroid often grows very rapidly and in some advanced cases, there may not be any treatment options. Specialist nurses, e.g. Macmillan nurses or district nurses, can help with the management of symptoms. Palliative care specialists and hospice teams can also be extremely helpful. When someone is diagnosed with cancer, their GP is informed and should also be able to help with pain relief and other symptom support.

March 2026