Aneurysmal Bone Cyst | Symptoms & Causes

What causes an aneurysmal bone cyst?

The cause of these cysts is unknown and controversial. They’re believed to grow in response to a disturbance of the blood vessels in the involved bone. They may grow because of a pre-existing tumor. In half of all cases, a pre-existing tumor, such as fibrous dysplasia, nonossifying fibroma, a solitary bone cyst or osteosarcoma also exists.

Abnormalities in the chromosomes (karyotype) of the tumor cells have been described, but the significance of these findings is unclear.

There is no definitive explanation for why these cysts occur. It’s important to know that there’s nothing that you could have done (or not done) that would have prevented your child’s cyst from developing.

What are the symptoms of an aneurysmal bone cyst?

While symptoms may vary child-to-child, the most common include:

  • swelling
  • mild to severe neurological problems (if the cyst is in your child's spine)
  • a fracture caused by the cyst (rarely)

It’s important to understand that the symptoms of aneurysmal bone cyst may resemble other medical problems, some of them which are very common and easy to treat, others which could be more serious.

Your child may experience symptoms differently. Therefore, it is important to be evaluated by a physician to get an accurate diagnosis. Always consult your child's physician if you have concerns.