Abstract
We report a rare case of synovial sarcoma of the chest wall in a child. A 12-year-old male presented to our pediatric surgery department with chief complaint of swelling accompanied by slight pain of the upper right side of the anterior chest wall since approximately 5 months. Firstly, we performed an ultrasound (US)-mass biopsy. Histopathological examination showed fibromatosis. After that, we underwent surgical resection. Pathological examination revealed a monophasic type synovial sarcoma. Immediately post-operation, the patient manifested a loss of the extension of the forearm, hand, and fingers on the right side. Physical therapy was performed with good results. On the basis of our diagnosis, we performed 6 cycles of multi-drug adjuvant chemotherapy and then radiotherapy. After 3 years of surgery, there was no evidence of recurrence. However, careful observation may be required.