What Is a Synovial Sarcoma?

Synovial sarcoma is a malignant tumor of the soft tissue originating from the joints, synovium, and tendon sheath synovium. The large joints of the extremities are the most common sites, and can also occur on the myometrium and fascia of the forearms, thighs, lower back. The main clinical symptoms were local swelling, lumps, pain, and limited mobility. Mainly surgical treatment.

Basic Information

English name

synovialsarcoma

Visiting department

orthopedics

Common locations

Large joints of the limbs

Common symptoms

Swelling, lump, pain, restricted movement

Causes of synovial sarcoma

The cause of synovial sarcoma is unclear.

Clinical manifestations of synovial sarcoma

Synovial sarcoma is a painless mass near the joint. Patients may develop swelling or masses around the joint. The mass can extend along the soft tissue to the entire forearm. Venous irritation can occur on the surface of the lump skin. The texture of the mass is medium, and it can be hard or soft. Pain, dull pain, or dull pain occurred in varying degrees, followed by severe pain at the later stage and significant nighttime pain. Some patients have limited local limb movements.

The lesions are near the joints of the extremities. The knee joint is the most common. The wrist, elbow, shoulder, soft tissue of the forearm, fingers, feet and other parts are also common, and can also occur on tendons and fascia.

Synovial sarcoma examination

1. X-ray inspection

(1) Soft tissue masses Not all masses clinically touched can be shown on the X-ray. Some show local soft tissue swelling, and some soft tissue masses appear. The density of the mass is slightly higher than that of the adjacent soft tissue, and the size is different. The larger one has the characteristics of growing across the joint.

(2) Calcification of soft tissue masses 30% of the soft tissue masses can show irregular and irregular calcifications. The cause of calcification may be related to factors such as bleeding, infection, necrosis, and cartilage calcification. The degree of calcification is related to the malignancy of the tumor. The less the calcification, the higher the malignancy.

(3) Bone changes Different degrees of osteoporosis, defects, or osteolytic damage can occur, such as osteoporosis, osteodystrophy, cystic bone defects, bone erosion, osteolytic damage, joint changes, etc. The early manifestations are mild osteoporosis, and later compression bone atrophy, thinning or cystic defects, and further development of bone destruction. Most of the bone destruction is irregular, and it can also be sac-like, which can invade multiple bones. Patients' joints are often unchanged, and may even invade the joints, causing the joint space to widen or soft tissue masses to appear, and joint effusions may also occur.

(4) Periosteal response Parallel, lace-like or needle-like periosteal reactions may occur. Although there are no clear periosteal reactions, thorn-like protrusions can be seen adjacent to the cortical bone, and Codman triangles appear.

2. Arteriography

It has great diagnostic value for synovial sarcoma. The angiography can show the characteristics of new capillaries, vascular lakes and other malignant tumors at the mass. It can also prevent surgery from damaging large blood vessels or perform intra-arterial chemotherapy.

Synovial sarcoma diagnosis

Synovial sarcoma is more common in adults and occurs in large joints of the extremities. It is a malignant tumor. If it occurs around the joint, the possibility of synovial sarcoma should be considered. CT and isotopic scans should be performed to determine the scope and general condition. The diagnosis depends on biopsy. Pathology report.

Differential diagnosis of synovial sarcoma

Synovial sarcoma is mainly identified by pathological examination and should be differentiated from adenocarcinoma, soft tissue acinar sarcoma, fibrosarcoma, leiomyosarcoma, and schwannomas.

Synovial Sarcoma Treatment

The treatment of synovial sarcoma is mainly based on surgical resection, and extensive resection is sought. If the blood vessel is invaded, the blood vessel needs to be resected together, the resection is incomplete, and the local recurrence rate is high. The disease is easy to metastasize to the lungs through hematology, and there are also lymphatic metastases. Those with larger drainage lymph nodes undergo lymphadenectomy when the tumor is removed. The 5-year survival rate of this disease is between 20% and 50%. Those with incomplete partial resection can be supplemented with radiotherapy. The effect of chemotherapy is currently uncertain. Synovial sarcoma is a highly malignant tumor. Due to distant metastasis in late stages, the condition varies, and the prognosis is relatively poor. The drug has no obvious effect on synovial sarcoma. Chemotherapy drugs are only used for postoperative adjuvant therapy, and antibiotics are applied to prevent infection.

Surgery

Synovial sarcoma requires radical surgery if it is not adjuvant or the lesion does not respond to adjuvant therapy.

If the lesion responds to preoperative radiotherapy and / or preoperative chemotherapy, the recurrence rate after local resection is less than 10%. For large larger lesions located near the extremities and around the trunk, the local recurrence rate is still high after a marginal resection, even if there is a satisfactory response to adjuvant therapy. Patients with small, superficial lesions at the distal extremities who are satisfied with neoadjuvant therapy have a low risk of recurrence. If local lymph node abnormalities are found on palpation, suggesting the possibility of metastasis, lymph node biopsy should be performed before surgery. If regional lymph nodes have metastasized, the disease is stage III and the prognosis is very poor.

For stage small tumors, extensive resection is the main method, and the recurrence rate is low. Once recurrence, extensive amputation is required. If the synovial sarcoma is not diagnosed before surgery, only a tenosynovial cyst is performed intrasacral or marginal resection. The tumor cannot be detected after surgery and the stage cannot be determined. When the pathological diagnosis is sarcoma, the lesion has expanded to the edge of the wound. With local evidence of recurrence, redesigning the surgical plan, the disadvantage of this method is that there is a medium risk of metastasis, and the recurrence is wider than the original, and treatment is delayed. The radiotherapy of the dangerous area to suppress the recurrence has the disadvantage that the scope of the spread during the operation is not certain, and the tumor cells are scattered in the scar of hypoxia, the treatment effect is worse. Radiation therapy of the hand or foot, which causes scarring of hand or foot dysfunction. Extensive amputation near the potential dissemination area increases disability, but is effective in controlling disease. The proximal large synovial sarcoma of stage limbs requires thorough surgical treatment. Extensive resection or amputation has a high recurrence rate. Radiation therapy is given before surgery, which significantly reduces the recurrence rate. Adjuvant therapy works better for this tumor because synovial sarcoma is sensitive to radiotherapy. Synovial sarcoma can be transferred to regional lymph nodes or distant lungs. For the former, lymph node masses are treated after radiotherapy for local resection, and time is spent for disease control. Chemotherapy is effective for small metastases.

2. chemotherapy

Adjuvant chemotherapy can occasionally produce better results, enabling patients who should be amputated to perform limb salvage surgery. Postoperative chemotherapy, as the ultimate treatment for local lymph nodes and / or distant metastases, only responds to some patients, but cannot achieve immediate or long-term control of the lesion.

3. Radiotherapy

Most synovial sarcomas respond satisfactorily to adjuvant radiotherapy. When radiotherapy is used as the ultimate or palliative treatment, the disease is usually relieved.

Prognosis of synovial sarcoma

Synovial sarcoma can metastasize to both regional lymph nodes and distant lungs. Incomplete resection has a higher recurrence rate. The disease metastasizes to the lungs, and lymph node metastasis is also common. Its incidence is about 20%. The 5-year survival rate of patients is 20% to 50%.