Myofibroma is a solitary myofibroblastic proliferative neoplasm occurring predominantly in infants and children. Myofibroma rarely arises in the oral and maxillofacial region. We report a case of myofibroma of the mandibular gingiva in a 15-year-old girl. She noticed a gradual swelling in the right mandibular molar region 1 month previously and was referred to our hospital. A soft elastic mass arising in the right molar gingiva, measuring 1.2×1.0-cm, was recognized. An incisional biopsy of the mass yielded a diagnosis of myofibroma. Because the tumor grew rapidly after the biopsy, excision of the tumor with alveolectomy of the mandibular molar region was performed. She has no evidence of recurrence 3 years 9 months after surgery.
