小児における歯牙を伴う下顎骨筋線維腫症

Myofibroma is a benign mesenchymal tumor derived from myofibroblasts. It is more common in children 's head and neck, but it is rare to involve the mandible and is easily confused with other jaw lesions.

This article reported a 13-year-old female patient with mandibular myofibroma associated with impacted teeth. The lesion presented insidiously as a painless swelling of the mandible. Imaging revealed a well-circumscribed expansile bone lesion. Intraoperatively, a firm gray-white mass with a clear demarcation from the surrounding bone was identified, and curettage was performed. Histopathological examination showed spindle-shaped cells arranged in fascicles. Immunohistochemistry demonstrated positivity for SMA and negativity for Desmin and S-100, with a low Ki-67 index. The diagnosis of myofibroma was confirmed.

Mandibular myofibroma, though benign, is rare and radiologically resembles ameloblastoma and other central fibro-osseous or vascular lesions. Definitive diagnosis relies on histopathology and immunohistochemistry. Complete resection is crucial to minimize recurrence.