Abstract
Objective: To report the histopathological and immunohistochemical aspects of oral cavity synoviosarcoma, since the last report of oral cavity was more than 5 years ago. This article shows an update on this neoplasm. Case Detail: A 9-year-old female patient with asymptomatic buccal floor synovinosarcoma. Histopathological and immunohistochemical exams were performed. Tumor removal surgery, and chemotherapy treatment. In the immunohistochemical study the case described showed positivity for vimentin, cytokeratin Pan and FLI-1. The histopathological report was shown to be a biphasic synoviosarcoma. Final Considerations: Synoviosarcoma is an extremely rare neoplasm, a well-defined malignant tumor representing 5.6% to 10% of all soft tissue sarcomas, which therefore makes its diagnosis more difficult. Histopathology and immunohistochemistry help precisely in the diagnosis, thus determining a good therapeutic approach. Treatment usually consists of surgical oncologic resection; may be followed by radiotherapy, chemotherapy and even immunotherapy.