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 are fluid-filled pockets in the bone that have not developed into actual bone or bone tissue. There are four main types of bone cysts: nonossifying fibromas (NOF), fibrous cortical defects, unicameral bone cysts and aneurysmal bone cysts (ABC). Nonossifying fibromas are the most common type of benign bone tumor found among children.
A bone cyst is typically treated using curettage and bone grafting. In some cases, additional treatments such as liquid nitrogen (a very cold substance) may be used to damage the tissue of the cyst. Some aneurysmal bone cysts will heal spontaneously following a simple biopsy. About one in five aneurysmal bone cysts will recur following treatment, almost always within the first 18 months.