A case of nodular fasciitis occured in the mandible is discribed in a 7-year-old male. Reports concerning nodular fasciitis are scarce. This leision is presented in which the condition clinically resembled malignancy and histopathologically resembled fibrous tumor. Because of them, it is difficult to make exact diagnosis of this lesion. In this case, a complete excisional biopsy was performed in four years ago, and there has not been recurrence up to the date. Electron microscopy shows that the myofibroblasts which had together with the features of fibroblasts and smooth muscle cells were mainly in this tissue.
