What Is a Giant Cell Tumor?
A Giant Cell Tumor (GCT) is a generally non-cancerous (benign) but aggressive tumor that usually develops in the bones. It often grows at the ends of long bones, especially near joints like the knee, wrist, or hip. Though it’s not usually cancer, GCT can still cause pain, swelling, and bone damage, and in rare cases, it may become cancerous or spread to the lungs.
What Causes Giant Cell Tumor?
The exact cause of giant cell tumors is not fully understood. However, they tend to occur in young adults between the ages of 20 and 40 and are slightly more common in women.
Some possible contributing factors include:
- Abnormal cell growth in bone tissue
- Previous bone trauma (rarely)
- Certain genetic conditions (although not typical)
GCTs are not inherited and usually occur without a clear reason.
Where Do Giant Cell Tumors Occur?
They most commonly develop in:
- The lower end of the femur (thigh bone)
- The upper end of the tibia (shin bone)
- The distal radius (wrist area)
- The sacrum (lower spine)
They tend to appear close to the joints and may affect movement if not treated.
Symptoms of Giant Cell Tumor
Symptoms depend on the tumor’s location and size. Common signs include:
- Localized pain that worsens over time
- Swelling and tenderness near the affected joint
- Limited joint movement
- A visible or palpable lump
- Bone fracture in severe cases (pathological fracture)
In spinal tumors, symptoms may include back pain or nerve issues like numbness or weakness.
How Is a Giant Cell Tumor Diagnosed?
Doctors typically use several methods to diagnose GCT:
- Physical exam – To check for swelling or pain near joints
- X-rays – To look for bone damage or visible tumor growth
- MRI or CT scans – To assess the size and spread of the tumor
- Biopsy – A small tissue sample is taken to confirm the diagnosis under a microscope
Treatment Options for Giant Cell Tumor
Treatment aims to remove the tumor and prevent it from returning. Common options include:
Surgery
- Curettage – Scraping out the tumor from the bone cavity
- Bone graft or cement – Filling the cavity after removal
- Wide resection – Removal of part of the bone (used in aggressive or recurrent cases)
- Joint reconstruction – If the tumor is near a joint, reconstruction or joint replacement may be needed
Medications
- Denosumab – A targeted drug that helps shrink the tumor and is used before or after surgery
- Bisphosphonates – Help prevent bone damage
Radiation Therapy
- Used in rare cases where surgery isn’t possible, especially in spinal or skull-base tumors. However, it’s avoided when possible due to risk of malignancy over time.
Can Giant Cell Tumors Be Cancerous?
While most GCTs are benign, in rare cases they can:
- Become malignant (cancerous)
- Spread to the lungs (known as benign pulmonary metastasis)
Regular monitoring is important even after treatment to catch any recurrence early.
Recurrence of Giant Cell Tumor
GCTs can come back, especially if not completely removed. Recurrence rates are higher with simple curettage but lower with wide excision or use of additional treatment like bone cement or denosumab.
Living with a Giant Cell Tumor
Most people recover well after treatment, especially if the tumor is detected early. Long-term care may involve:
- Physical therapy to restore joint function
- Regular follow-up scans to check for recurrence
- Emotional support, especially if extensive surgery was needed
With proper care, the majority of patients can return to normal or near-normal activity.
Who Is at Risk?
Giant cell tumors mostly affect:
- Adults aged 20–40
- Women (slightly more common)
- People without any significant prior health conditions
They are rare in children and older adults.