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    • In molecular genetics most synovial

    2018-11-12

    In molecular genetics, most synovial sarcomas (90%) demonstrate a specific translocation between chromosome X and chromosome 18 (p11.2; q11.2). This includes the SYT gene on chromosome 18 and one of several homologous genes (SSX1, SSX2, and SSX4) on the X chromosome. This leads to the expression of the unique SYT/SSX fusion protein in all cases of synovial sarcoma, which suggests a crucial role of the fusion protein in the etiology of this tumor. Clinically, the patient typically presents with a slow-growing mass that may grow over weeks to months. Deeper lesions, which are difficult to detect, may become very large. The groin area is a rare anatomical site for the tumor. In a study reported by St Jude Hospital in 2009, among 300 nonrhabdomyosarcoma soft tissue sarcoma young patients, only six were diagnosed with groin synovial sarcoma. Image studies can appear as multilobular, septated masses that show heterogenous signal intensity on T1WI and T2WI on magnetic resonance imaging. Heterogenous pkg inhibitor enhancement is caused by central necrosis, calcifications, and hemorrhage within the tumor. Three components are classically described: cellular with an intermediate signal; necrotic or hemorrhage with a high signal; fibrous or calcified with a hypointensity, and this is known as the “triple sign”. Slow growth of the tumor can result in superficial pressure cortical erosion, periosteal reaction, and osteoporosis. The primary treatment of synovial sarcoma is surgery, comprising wide excision with negative margins. It should be carried out through normal adjacent tissue planes. Adjuvant radiotherapy is considered helpful for local recurrence control. Synovial sarcoma demonstrates moderate chemosensitivity and approximately 50% response rate due to doxorubicin-based regimens. Synovial sarcomas involving major vessels, such as the axillary artery and femoral artery were thought unresectable in the past. In a review of the literature, only 5–10% of soft tissue sarcoma infiltrated or encased vascular structures. Historically, amputation of limbs was considered the only resolution to obtain negative surgical margins. With the advancement of operative technique and available grafts, limb preservation with tumor and vascular en bloc resection and reconstruction with saphenous vein graft, femoral venous grafts, or synthetic grafts can be achieved. The first description of sarcoma resection in the extremity with arterial replacement was reported by Fortner et al in 1977. There were several studies showing that limb salvage combined with vascular reconstruction offers rates of local control and overall survival that are comparable to amputation. Estimation of resection length is based on a preoperative image study, which is helpful for identifying the appropriate graft to choose. In a large series presented by Schwarzbach et al in 2005, in the iliofemoral and femoropopliteal region above the knee, they used predominantly synthetic grafts for arterial reconstruction. This can reduce operative time and preserve the greater saphenous vein (GSV). Long-term patency rates between the synthetic graft and autologous graft were identical. The venous reconstruction protocol is controversial. Some studies suggest that if ipsilateral GSV is preserved and patent, the remaining femoral vein stumps could be ligated. However, if the GSV is sclerotic or resected together, reconstruction should be performed. Recently, however, venous reconstruction is associated with better outcome, and less morbidity such as extremity swelling, seroma formation, and wound infection is seen. In Schwarzbach et al\'s series, venous patency rate was 54.9% with PTFE graft reconstruction. Due to the rapid formation of collateral drainage, occlusion of a venous bypass several weeks after surgery usually would not require a second revision operation. In our case, we performed both arterial and venous reconstruction with synthetic grafts due to the long segment of vascular and complicated soft tissue defect. Cautious administration of low-dose heparin intraoperatively is sufficient for occlusion prophylaxis. Further oral form anticoagulant or antiplatelet therapy was prescribed only for selected patients. The added risk of complications (primarily bleeding) with vascular procedures performed on patients treated with aspirin is measurable. In our case, no heparin injection or postoperative anticoagulant and antiplatelet therapy were given because the girl was young and medically healthy without such myocardial or cerebral risk factors. After 8 months, no sequelae of lower limb swelling, circulation compromised, or wound infection occurred. Adjuvant radiotherapy may have potential adverse effects on the reconstructed graft, such as occlusion or arterial blowout. A radiation dose exceeding 50 Gy can induce vessel wall abnormality. Nevertheless, there is still no published series about the effect of radiotherapy and extremity vascular reconstruction following a sarcoma surgery.