Giant Cell Tumor Specialist Explains The Treatment
The giant cell tumor (GCT) was first discovered in 1818; back then, it was called osteoclastoma. This lesion is considered benign despite having the potential for pulmonary metastasis; cases that become malignant are extremely rare and associated with a post-radiotherapy condition.
Who Develops GCT?
GCT is more prevalent among bone tumors in the Asian population amongst people in their 30s and 40s. The lesion appears in the distal femur, the proximal tibia, and the distal radius. Metastasis occurs in about 4% of patients.
It is extremely important to remember that the giant cell tumor does not affect patients who do not have fully developed bones.
When Do Medical Experts Suspect GCT?
Usually, the giant cell tumor begins with a mild pain that progressively worsens. Over time, the patient will notice swelling in the joint region, a tumor may also be seen, and they may experience difficulty in movement. In about 10% of cases, the patient will arrive at the emergency room with a fracture. Cases of giant cell tumor in the spine may present during radiculopathy.
How Are Giant Cell Tumors Revealed In X-Rays?
The lesion of giant cells is usually eccentric, located in the meta-epiphyseal region of the bone whose edges are not sclerotic. In some cases, there may already be an established fracture.
What Is The Role Of Resonance In GCT?
Magnetic resonance imaging is used to investigate the results of the radiographs. It helps us understand the extent of the disease in the medullary part of the bone.
In T1 sections, we will see a homogeneous lesion with an intermediate signal; in T2 sections, there will be a heterogeneous signal since hemosiderin components produce a low signal, and those with water will have a high signal.
The gadolinium contrast will spread over the lesion, confirming its solid nature.
GCT With Eurysmal Bone Cyst
Sometimes the giant cell tumor will be multiloculated on tomography or resonance, usually because these areas of trabeculae were left behind at the time of action of the giant cells, the osteoclasts. Whenever we see this, we suspect the presence of an associated aneurysmatic bone cyst that occurs in about 14% of cases.
Bone scans have no role in the diagnosis of GCT. They are only used to show if there are lesions in the parts of the body (hyperparathyroidism). In spite of this, the image of the GCT on scintigraphy is very characteristic, as it presents in the periphery and a central photopenia.
The biopsy will show us the presence of the classic giant multinucleated cells (giant cells) and the tumor from which they originated.
It is important to highlight that the presence of these cells does not confirm the diagnosis of the tumor; the stroma mononuclear ovoid cell confirms it.
The literature on this topic is quite extensive, and there has been significant progress in the treatment of this disease with the understanding of pathways related to the nuclear factor kappa-B ligand (RANKL) and the advent of Denosumab as neoadjuvant in some cases.
What Is The Multicentric Giant Cell Tumor?
The multicentric giant cell tumor is extremely rare; it only occurs in 1% of cases.
It’s been given this name because the lesion appears at the same time in various parts of the body. Unlike the classic GCT, the epicenter is usually found in short bones of the hand and foot; the condition is more common in males.
In this situation, laboratory tests must be performed to differentiate it from the brown tumor of hyperparathyroidisms, such as serum calcium, phosphate, and parathyroid hormones.
How Is GCT Treated?
Back in the day, treatment involved surgically removing the tumor. Some researchers recommend large block resections with a recurrence rate of around 5%.
Currently, we stick to en bloc resection only in cases that present with an intra-articular fracture. In general terms, the current treatment recommended for GCT is curettage and local adjuvant, leading to a recurrence rate between 6-25%.
The Use Of Denosumab
GCT is mainly treated with a monoclonal antibody and RANKL inhibitor called Denosumab. Now, we use this treatment when surgery is too risky.
Can GCT Metastasize?
About 2% of cases will have metastasis, and in most cases, it is related to chronic disease.
The anatomopathological study of lung metastasis is similar to that of the primary giant cell tumor. The behavior of pulmonary lesions in the GCT is totally unpredictable. Some lesions will be spontaneously stable; others will have very slow growth and their surgical resection successful.
In other cases, we may have a very aggressive lesion that impacts the patient’s lungs. The medical team will only opt for surgery in these cases when they know the patient is healthy enough to recover and believe the lesion can be removed easily.
Lesions that can’t be removed due to their locations can be treated with interferon.
Is GCT Malignant?
GCT is considered a benign aggressive tumor with a rare potential for metastasis, but it does have a malignant form.