Abstract
High-grade myofibroblastic sarcoma is a rare mesenchymal tumor with a high recurrence and metastatic rate. Few cases of high-grade myofibroblastic sarcomas have been reported. Herein, we report a rare case of undifferentiated, high-grade myofibroblastic sarcoma with an unclear primary site, initially presenting with oral symptoms. High-grade myofibroblastic sarcoma was diagnosed following an excisional biopsy of a gingival tumor. After this excisional biopsy, systemic imaging revealed multiple metastases in the tonsil, lung, liver, kidney, and eye. The patient underwent two cycles of chemotherapy (doxorubicin). During follow-up, the tumor progressed rapidly and metastasized to the skin of the head and neck. The patient expired three months after the initial examination.