Giant Cell Tumor
Giant cell tumor is one of the more common benign bone tumors, occurring in adults ages 20 – 40 years. While a giant cell tumor can occur in any bone, it is most commonly located in the (metaphysis) or at the end (epiphysis) of the thigh bone (femur) or shin bone (tibia).
Giant cell tumors are named for how the biopsied tissue looks under a microscope. They are made up of a combination of cell types – large bone destroying cells (like osteoclasts) and a type of white blood cell (histiocyte). 1 Giant cell tumors are benign (meaning they aren’t cancerous) but they are very aggressive, destroying healthy bone and joints. There are rare cases that the tumor spreads to the lungs. The lesions in the lungs are usually benign as well. 1
There is no known cause of giant cell tumor and it is not associated with inherited disorders like some cancers.
Signs and Symptoms of Giant Cell Tumor
Patients with giant cell tumors usually describe a deep, persistent pain in the area of the tumor that isn’t related to an injury. The pain progressively worsens and may result in limited function. Sometimes there is swelling of an effected area, especially if the joint line has been affected. Because giant cell tumors destroy bone, there is risk for pathologic fracture in the area of the tumor.
An x-ray is the first test that will show a tumor. Giant cell tumors have a recognizable pattern on x-ray – a large, almost transparent area in the bone where the tumor has destroyed bone cells. The bone may look like it’s expanding in the area of the tumor.
An MRI may be done to determine if the tumor is extending into the soft tissue around the area or to assess the extent of bony destruction.
A chest x-ray or CT scan is usually done to see if there has been any spread of the tumor to the lungs.
Surgery is the best treatment for a giant cell tumor. During surgery the tumor is curetted (scooped out) and then the space is filled with a ‘bone void filler’. The filler may be bone graft material like allograft (bone bank tissue), autograft (the patient’s own bone), bone cement, or a combination of these things. There is some evidence that use of bone cement decreases the chance of the tumor returning (local recurrence) because of the heat that the cement gives off when it is mixed and placed in the area.
Another approach to surgery is to curette the tumor then pour liquid nitrogen, hydrogen peroxide, or phenol in the area, followed by filling it with bone cement. These substances kill tumor in the area so their use may decrease the likelihood of local recurrence.
In some situations, the tumor has caused so much bony destruction that a larger reconstructive surgery is necessary. The approach is determined by the location of the tumor and the amount of destruction, sometimes requiring joint replacement surgery or plating of the affected bone.2
Prognosis of Giant Cell Tumor
While surgical removal of a giant cell tumor is considered curative and people can return to full activity, it is important to be diligent about follow-up. There is a potential for the tumor to return so regular (yearly) x-rays are recommended to assure the tumor isn’t recurring.
1. Werner, M. (2006). Giant cell tumour of bone: morphological, biological and histogenetical aspects. Springer-Verlag , 30, 484-48
2. Mendenhall W, Zlotecki R, Scarborough M, Gibbs C, Mendenhall N (2006). "Giant cell tumor of bone". Am J Clin Oncol 29 (1): 96–9