Bone Cyst – Overview
A bone cyst is a fluid-filled cavity that develops inside a bone, typically in children and young adults. Although they can sound alarming, most bone cysts are benign (non-cancerous) and often discovered accidentally on X-rays taken for unrelated reasons, like after a fall or injury.
Bone cysts are generally painless, but they may weaken the affected bone over time, increasing the risk of fractures. If a cyst is large, growing, or located in a critical bone like the femur or humerus, treatment might be required.
There are two main types of bone cysts:
- Unicameral (simple)
- Most common in children aged 5–15.
- Usually found in long bones, especially the upper arm (humerus) and thigh bone (femur).
- Typically resolves with age or minor intervention.
- Aneurysmal
- Less common but more aggressive.
- Filled with blood, not just fluid, and can grow rapidly.
- Can affect both children and adults.
- More likely to cause swelling, pain, and bone expansion.
Symptoms of a bone cyst may include:
- A dull ache or mild pain in the affected area
- A noticeable lump or swelling (in some cases)
- Limited range of motion if near a joint
- Sudden pain if a cyst causes the bone to fracture
Most bone cysts do not become cancerous, but they must be monitored to ensure they do not interfere with growth or structural stability. In South Africa, they are typically diagnosed by orthopaedic specialists at public or private clinics when investigating unexplained pain or injury in children and teens.
While many cysts resolve on their own, some require surgical drainage, steroid injection, or bone grafting, especially if they’re large or recurrent.
👉 [Next: Causes and Risk Factors of Bone Cysts]
