A bone cyst is a fluid-filled hole that develops inside a bone. They mostly occur in children and young adults. Bone cysts do not usually cause any symptoms, they are not cancerous and they do not usually pose a serious threat to health.
However, larger cysts can cause a bone to weaken, making it more vulnerable to fracture. This can lead to symptoms such as pain, swelling or not being able to move or put weight on a body part.
Bone cysts do not usually have any symptoms. They may not be discovered until you fracture (break) the bone, or until you have an X-ray