Bone cyst - Diagnosis

Bone cysts can usually be diagnosed by looking at an X-ray of your child's bone. This will highlight any hollow cavities or fractures in the bone.

In many cases, a bone cyst will only be discovered by chance when X-rays are used to diagnose an unrelated condition. Alternatively, a diagnosis may be confirmed after the affected bone has been fractured.

Further testing

Further testing is usually only required if:

• the cyst has developed on the end of a long bone that is still growing (an area of the bone known as the growth plate) and there is concern that it may affect normal physical development
• there are additional symptoms, such as unexplained weight loss, which mean a diagnosis of bone cancer needs to be ruled out (it should be stressed that bone cancer is very rare, with only 600 new cases occurring in the UK each year)
• the cyst is so large that the affected bone is at risk of fracturing (breaking)

In these circumstances, two tests may be used:

• a computerised tomography (CT) scan, where a series of X-rays are taken and a computer is used to produce a more detailed three-dimensional image of the bone
• a magnetic resonance imaging (MRI) scan, which uses strong magnetic fields and radio waves to produce a detailed image of the inside of the bone