Synovial sarcoma is a rare type of soft tissue cancer that can develop in various parts of the body. The extremities, including the hand, are frequently affected sites. This cancer can impact individuals across all age groups, though it is more often observed in young adults.
Understanding Synovial Sarcoma in the Hand
Synovial sarcoma, despite its name, does not originate from the synovium, the lining of joints. Instead, it arises from primitive mesenchymal cells, a type of stem cell found in various connective tissues. This cancer is classified as a soft tissue sarcoma, developing in non-bony tissues such as muscles, ligaments, fat, and nerves. It accounts for approximately 5% to 10% of all soft tissue sarcomas.
The hand and wrist are common locations for synovial sarcoma, with the hand accounting for about 4% of cases. It primarily affects individuals between 10 and 40 years of age. There is a slight male predominance, and its occurrence is similar across different ethnic groups.
Recognizing Symptoms in the Hand
The initial symptoms of synovial sarcoma in the hand can be subtle and may resemble those of more common, benign conditions. A noticeable lump or mass is often the first sign, which can be painless. This lump may slowly increase in size over time, sometimes being present for over a year before diagnosis.
As the tumor grows, it can lead to swelling in the affected area. If the mass presses on nearby nerves, individuals may experience numbness or weakness in the hand or fingers. Joint stiffness or a limited range of motion can also occur, particularly if the tumor is located near a joint.
Diagnostic Procedures
Diagnosing synovial sarcoma in the hand involves a comprehensive approach, beginning with a detailed clinical examination. Imaging techniques are then used to visualize the mass and assess its characteristics. Plain X-rays may reveal a soft tissue mass, sometimes showing spotty calcifications within the tumor.
Magnetic Resonance Imaging (MRI) is the preferred imaging method for soft tissue sarcomas, providing detailed images of the tumor’s size, exact location, and its relationship to surrounding structures like nerves and blood vessels. Computed Tomography (CT) scans may be used to further assess the mass and to check for any spread of the cancer, such as to the lungs.
A biopsy is a definitive diagnostic step, where a small tissue sample is taken from the tumor. This can be a core needle, incisional, or excisional biopsy. The tissue is then examined by a pathologist, who performs immunohistochemistry and genetic testing. A specific genetic marker, the SYT-SSX fusion gene, which results from a chromosomal translocation, is characteristic of synovial sarcoma and is detected in over 90% of cases, confirming the diagnosis.
Treatment Strategies
Treatment for synovial sarcoma of the hand is multimodal, involving a combination of therapies. The primary treatment is surgical removal, aiming for wide local excision with clear margins to reduce the risk of local recurrence. Advancements in surgical techniques have made limb-sparing procedures more common, reducing the need for amputation. However, due to the hand’s intricate anatomy, achieving clear margins can be challenging.
Radiation therapy is frequently used with surgery, either before (neoadjuvant) or after (adjuvant) the procedure. Preoperative radiation can shrink the tumor, potentially making surgery more effective, while postoperative radiation helps eliminate any remaining cancer cells to lower the risk of local recurrence. The local radiation dose ranges from 40 to 60 Gy.
Chemotherapy may be considered for high-grade tumors, larger tumors, or when there is evidence of metastatic disease. It can be administered before surgery to reduce tumor size or after surgery to target any microscopic cancer cells that may have spread. Anthracycline-based chemotherapy, sometimes combined with ifosfamide, is a common approach. Chemotherapy’s overall benefit in all cases remains under study, but it can improve survival rates in selected patients, particularly those with tumors larger than 5 cm.
Prognosis and Post-Treatment Care
The prognosis for synovial sarcoma in the hand is influenced by several factors, including tumor size, tumor grade, and whether the cancer has spread at diagnosis. Smaller tumors and those without metastasis at diagnosis have more favorable outcomes. For localized synovial sarcoma of the hand, the estimated 5-year overall survival rate has been reported around 80%.
Long-term follow-up care is important to monitor for any signs of recurrence, which can occur locally or as distant metastases, often in the lungs. This follow-up includes regular clinical examinations and imaging scans, such as MRI and CT scans, to detect any new lesions early. Patients with synovial sarcoma should be followed for more than 10 years, as metastases can develop late.
Rehabilitation is an important part of post-treatment care for synovial sarcoma of the hand. Physical therapy is initiated early to help restore hand function, improve range of motion, and strengthen muscles affected by surgery or radiation therapy. Psychological support can also be beneficial, helping individuals cope with the emotional challenges of cancer treatment and recovery.