You are in: eMedicine Specialties > Orthopedic Surgery > NEOPLASMS Synovial Cell SarcomaArticle Last Updated: Jun 1, 2005AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Mark Clayer, MD, MBBS, FRACS, FAOrthA, Head of Musculoskeletal Tumor Service, Queen Elizabeth Hospital; Senior Visiting Medical Specialist, Department of Orthopaedics and Trauma, Royal Adelaide Hospital and Women's and Children's Hospital Mark Clayer is a member of the following medical societies: Australian Medical Association and Australian Orthopaedic Association Editors: Howard A Chansky, MD, Associate Professor, Department of Orthopedics and Sports Medicine, University of Washington Medical Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Sean P Scully, MD, PhD, Professor, Department of Orthopedics, University of Miami; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: synovial cell sarcoma, synovioma INTRODUCTIONSection 2 of 11
  Synovial sarcoma is a rare soft tissue sarcoma with features of epithelial differentiation. In contrast with its name, synovial sarcoma is not associated with synovial joints. It tends to arise in younger patients with a mean age of approximately 30 years. ProblemSynovial sarcoma is a high-grade tumor but typically is associated with a history of a long-standing nodule, sometimes present for years, which has increased rapidly in size over a few months. Therefore, it is sometimes overlooked. The tumor spreads along fascial planes and, thus, can be much more widespread than apparent on initial evaluation. Frequency
EtiologySynovial sarcoma is characterized by a specific chromosomal translocation t(X;18)(p11;q11) that is observed in more than 90% of cases. This defect appears to be the underlying cause of the tumor, although how the resulting fusion protein leads to transformation is poorly understood. PathophysiologyThe t(X;18)(p11;q11) translocation fuses the SYT gene from chromosome 18 to either of 2 homologous genes at Xp11, either SSX1 or SSX2. The fusion proteins SYT-SSX1 and SYT-SSX2 are believed to function as aberrant transcriptional regulators, resulting in either activation of protooncogenes or inhibition of tumor suppressor genes. The downstream targets of these fusion proteins that lead to transformation have not been identified. A correlation appears to exist between the histologic subtype of the tumor and either of the 2 fusion proteins. Biphasic tumors, containing both epithelial and spindle cell components, express the SYT-SSX1 transcript while monophasic tumors with only a spindle cell component may express either transcript. ClinicalSynovial sarcoma usually presents within the first 3 decades of life and generally is associated with a history of a small nodule that has increased rapidly in size. The mass often is painful and is located deep. Most commonly, it is situated around the knee, but it also can appear in the hands and feet. RELEVANT ANATOMYSection 3 of 11
This malignancy can affect any part of the appendicular skeleton, including the hands and feet. The relevant anatomy depends on the site involved. CONTRAINDICATIONSSection 4 of 11
There are no contraindications to surgery as it is a potentially life-saving procedure. WORKUPSection 5 of 11
Lab Studies
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Diagnostic Procedures
Histologic FindingsMacroscopically, the tumor is a grayish-white and often has a greasy feel. Microscopically, it can be either monophasic or biphasic. Typically, it is biphasic and consists of plump round cells and spindle-shaped fibroblasts alternating with glandularlike areas that are lined by synovial-like cells and contain mucin. The monophasic variant does not have the glandular areas. Punctate areas of calcification may be observed. StagingStaging requires local imaging with MRI. The most likely site of distant spread (the lungs) can be observed with CT scanning. Synovial sarcoma is a high-grade lesion. TREATMENTSection 6 of 11
Medical therapyThe use of chemotherapy in the treatment of this sarcoma remains controversial. Ladenstein et al have reported improved survival rates with the use of adjuvant doxorubicin and cyclophosphamide-based chemotherapy. Surgical therapySurgical excision remains the mainstay of treatment of this sarcoma. The tumor extends along fascial planes. Therefore, careful preoperative planning with MRI is necessary prior to embarking on a wide excision. Because of its predilection for the popliteal fossa, limb salvage may not be possible due to the proximity of the neurovascular structures. Preoperative detailsStaging prior to surgery is essential, as this tumor spreads along fascial planes. Synovial sarcoma has the ability to metastasize via the lymphatic system. Venous metastasis can occur as well. Synovial sarcoma is the soft tissue sarcoma most likely to invade adjacent bone. Intraoperative detailsA radical or wide resection is indicated. The mass must be tagged so that the location of any close or contaminated margins can be inferred from the inked specimen. Postoperative detailsPostoperative radiation therapy usually is required, particularly if the margins are close due to vital neurovascular structures. The decision on timing of radiation delivery (before or after surgery) is controversial; each has merits and drawbacks. Local radiation usually is 40-60 Gy. Vital neurologic structures, open physes, or an extreme peripheral location (hand or foot) can make external beam radiation treatment potentially hazardous. Brachytherapy is an alternative consideration. Follow-upFollow-up involves clinical examination, MRI of the surgical site, and CT scan of the chest. No specific recommendation exists, but the author rescans and reviews every 3 months for the first 2 years and then every 6 months for the next 3 years. Most metastatic disease presents within the first 2 years, but late recurrence has been documented. COMPLICATIONSSection 7 of 11
The surgical complications are related to the site involved but include the general complications of wound infection, wound breakdown, neurologic or vascular injury, and hematoma or seroma formation. Specific complications to this tumor are local recurrence and distant metastasis. The risk of local recurrence is directly proportional to the adequacy of surgical clearance. Therefore, a wide excision is mandatory to reduce this risk. Essential neurologic structures may make a wide clearance impossible, especially in the popliteal fossa, and the consideration of nerve grafting and/or later muscle transfers may need to be considered to allow the wide margin needed. OUTCOME AND PROGNOSISSection 8 of 11
Synovial sarcoma has a prognosis of approximately a 50% survival rate at 5 years. A slight improvement in survival rates recently has been reported with the use of doxorubicin-based chemotherapy as adjuvant therapy (5-y survival rate of 73% reported by Ladenstein et al). Recurrence of the disease has been reported up to 69 months following treatment and implies a worse prognosis with survival rates of less than 25%. Prognostic factors that correlate with a better prognosis have been described and include the following:
Other prognostic factors that have not been reported to reliably improve survival rates include the following:
FUTURE AND CONTROVERSIESSection 9 of 11
The most controversial aspect of treating individuals with synovial sarcoma is whether to use chemotherapy as an adjuvant. Reports in the literature are split equally between demonstrating a survival benefit and no improvement in survival rates with the addition of ifosfamide and/or Adriamycin. Synovial sarcoma is associated with a cytogenetic abnormality t(X;18), which produces a unique gene (SYT/SSX1 or SYT/SSX2) and subsequent gene product. This unique gene product and/or gene may prove to be a useful focus for immunotherapeutic attack. MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
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