Tenosynovial Giant Cell Tumor
Tenosynovial Giant Cell Tumor (TGCT) is a rare, benign (non-cancerous) tumor that affects the lining of joints, tendons, and bursae. This condition can lead to significant pain and functional limitations if left untreated.
Key Takeaways
- Tenosynovial Giant Cell Tumor (TGCT) is a rare, non-cancerous growth affecting joint linings and tendons.
- It often presents with gradual onset of swelling, pain, and stiffness in the affected joint.
- Diagnosis typically involves physical examination, MRI imaging, and a biopsy for confirmation.
- Surgical removal is the primary treatment, though recurrence is possible, and other therapies may be considered for diffuse or recurrent cases.
What is Tenosynovial Giant Cell Tumor?
Tenosynovial Giant Cell Tumor (TGCT) is a rare, benign proliferative disorder originating from the synovial membrane, which lines joints, tendon sheaths, and bursae. It is characterized by an overgrowth of cells within these tissues, forming a mass that can be localized or diffuse. While not cancerous, TGCT can be locally aggressive, causing damage to surrounding bone and cartilage, leading to pain, swelling, and restricted joint movement. The tumor is thought to arise from a chromosomal translocation that leads to the overexpression of colony-stimulating factor 1 (CSF1), which attracts CSF1R-expressing cells, including macrophages, forming the bulk of the tumor.
TGCT can affect any joint but is most commonly found in the knee, hip, ankle, shoulder, and fingers. It is classified into two main types: localized TGCT (previously known as giant cell tumor of the tendon sheath), which is more common and typically affects fingers and toes, and diffuse TGCT (previously known as pigmented villonodular synovitis or PVNS), which is less common but more aggressive, often affecting larger joints like the knee or hip. According to the American Academy of Orthopaedic Surgeons, TGCT is a rare condition, with an estimated incidence of 1.5 to 4 cases per million people per year.
Recognizing Tenosynovial Giant Cell Tumor: Symptoms and Diagnosis
Recognizing tenosynovial giant cell tumor symptoms is crucial for early intervention. The symptoms typically develop gradually over months or even years and can vary depending on the size and location of the tumor. Common symptoms include:
- Swelling: Often the most noticeable symptom, a persistent, sometimes fluctuating swelling around the affected joint or tendon.
- Pain: Aching or throbbing pain in the affected area, which may worsen with activity.
- Stiffness: Reduced range of motion in the joint, making everyday activities difficult.
- Locking or Catching: A sensation of the joint getting stuck, particularly in diffuse forms.
- Palpable Mass: In some cases, a soft, movable lump can be felt under the skin.
The process of tenosynovial giant cell tumor diagnosis involves a thorough clinical evaluation. A physician will perform a physical examination to assess the swelling, tenderness, and range of motion. Imaging studies are essential for confirming the presence and extent of the tumor. Magnetic Resonance Imaging (MRI) is the preferred imaging modality, as it can clearly show the characteristic features of TGCT, such as the synovial proliferation and hemosiderin deposits (due to old bleeding within the tumor). While imaging can strongly suggest TGCT, a definitive diagnosis requires a biopsy, where a small tissue sample is taken from the tumor and examined under a microscope by a pathologist.
Tenosynovial Giant Cell Tumor Treatment Options
The primary tenosynovial giant cell tumor treatment is surgical removal. The goal of surgery is to remove the entire tumor while preserving joint function. The specific surgical approach depends on the type, size, and location of the tumor:
| Treatment Type | Description | Considerations |
|---|---|---|
| Surgical Excision | Removal of the tumor, either through open surgery or arthroscopically (minimally invasive). | Primary treatment; aims for complete removal to prevent recurrence. |
| Synovectomy | Removal of the affected synovial lining, often used for diffuse forms. | Can be extensive for diffuse TGCT; higher risk of recurrence if not completely removed. |
| Targeted Therapy | Medications like pexidartinib (a CSF1R inhibitor) for diffuse, symptomatic, and unresectable TGCT. | Approved for specific cases; can have significant side effects. |
| Radiation Therapy | Used in select cases, particularly for recurrent or inoperable diffuse TGCT. | Can help control tumor growth; potential for long-term side effects. |
For localized TGCT, surgical excision is usually curative, with a low recurrence rate. However, diffuse TGCT has a higher rate of recurrence even after extensive surgery, sometimes requiring multiple operations. In cases of diffuse TGCT that are not amenable to surgery or have recurred multiple times, targeted therapies, such as pexidartinib, may be considered. These medications work by inhibiting the CSF1R pathway, which plays a key role in the tumor’s growth. Radiation therapy is another option for managing recurrent or inoperable diffuse TGCT, aiming to control tumor growth and alleviate symptoms. Close follow-up with a specialist is essential after treatment to monitor for any signs of recurrence.
