Non-cancerous conditions of the bone

A non-cancerous (benign) condition of the bone is a change to bone cells, but it is not cancer. Non-cancerous conditions do not spread (metastasize) to other parts of the body and are not usually life-threatening.

Bone cysts are the most common non-cancerous condition of the bone. A bone cyst is a fluid-filled area in the bone. They are most often found in the long bones of the legs and arms, but they can also occur in the bones of the pelvis and spine. Bone cysts are more common in children and teenagers, though they can occur in adults as well.

There are 2 types of bone cysts.

Unicameral bone cysts are the most common type of bone cysts. They are found in men twice as often as they are found in women. Unicameral bone cysts can cause a bone to break (fracture).

Aneurysmal bone cysts are not as common as unicameral cysts. These cysts can be locally aggressive. As they get larger, they can cause pain, swelling, and bone fractures.

Small bone cysts that don’t cause symptoms and don’t increase the risk of the bone breaking are usually just watched for changes. Larger cysts that are causing symptoms or weakening the bone are usually removed with surgery.

Expert review and references

  • American Academy of Orthopaedic Surgeons. OrthoInfo: Unicameral Bone Cysts. 2013.
  • Hakim DN, Pelly T, Kulendran M, Caris JA . Benign tumours of the bone: a review. Journal of Bone Oncology. 2015.
  • Joyce MJ . Benign bone tumours. Beers, M. H., & Berkow, R., (Eds.). Merck Manual Professional Edition.
  • Joyce MJ . Other bone lesions. Beers, M. H., & Berkow, R., (Eds.). Merck Manual Professional Edition.
  • Mascard E, Gomez-Brouchet A, Lambot K . Bone cysts: unicameral and aneurysmal bone cyst. Orthopaedics & Traumatology: Surgery & Research. 2015.
  • Tedesco N. Medscape Reference: Aneurysmal Bone Cyst. 2015: