Report Of A Misdiagnosed Case Of Chest Wall Synovial Sarcoma With Distant Multiple Metastasis And Literature Review

Objective:To report a case of chest wall synovial sarcoma with distant multiple metastasis misdiagnosed as neurofibromatosis,analyze its imaging and pathological features and treatment,and improve the clinician's understanding of synovial sarcoma.Methods:We retrospectively analyzed of a case of right chest wall synovial sarcoma with distant metastasis misdiagnosed as neurofibromatosis was diagnosed in Qilu Hospital of Shandong University in December 2018.The clinical manifestations,examination results,diagnosis and treatment were collected.and the related literatures of synovial sarcoma were reviewed to summarize the characteristics of diagnosis and treatment.Results:The patient was 28-year-old male,who was admitted to hospital because he discovered tumors on his right chest wall and left ring finger for 3 months.After admitted,relevant preoperative examinations were completed.The results of enhancing chest CT and enhancing chest soft tissue MRI were considered as neurofibromatosis and then he underwent the surgery to resect the tumors.The postoperative pathological diagnosis was synovial sarcoma on the right chest wall and the tumor on the left ring finger was considered as metastasis.Immunohistochemistry results showed that the expression of TLE-1,Fli-1,CD99 and Bcl-2 were positive.FISH detection of SYT-SS18 gene fusion confirmed that SS18 was positive.The patient received regular chemotherapy and review after surgery.During the chemotherapy period,the tumor on the left ring finger recurred and it had metastaized to bilateralis thighs and left buttock.Then the patient underwent surgery again.At present,the general condition of the patient is acceptable and there is no sign of tumor metastasis or recurrence.Conclusion:1.Synovial sarcoma is relatively rare in clinical,mainly in young adults aged 15-40 years.It mostly occurs near the joints of limbs,but lacks typical clinical manifestations.The painless soft tissue tumors may be the main manifestation.2.The imaging findings of synovial sarcoma are not specific.On CT scan,the tumors appear to be equal or slightly lower to muscle density and there are necrosis and cyst degeneration with lower density.On MRI T1WI,the tumors are slightly high signals or mixed high signals and on T2WI,they are mixed signals which are composed of medium and slightly high signals.3.The diagnosis of synovial sarcoma mainly depends on pathological examination combined with immunohistochemistry and molecular genetics4.At present,there is no standard treatment for synovial sarcoma.Its treatments mainly include surgery,radiotherapy,chemotherapy,molecular targeted therapy,cellular immunotherapy and so on.5.There is a high rate of misdiagnosis of synovial sarcoma in clinical.Clinicians need to improve their understanding of synovial sarcoma and assist its diagnosis and treatments by imaging,immunohistochemistry and molecular genetics so that can reduce the rate of misdiagnosis.