Central myofibroma of the maxilla: A case report

Myofibroma is a benign tumor characterized by the proliferation of spindle cells originating from myofibroblasts. This tumor, common in infants, rarely occurs in the oral cavity of adults. Owing to its clinical and pathological characteristics, myofibroma has often been misdiagnosed, leading to inappropriate treatment choices. We report here a rare case of a myofibroma occurring in the maxillary bone of a 57-year-old woman. A rapidly growing mass was observed in the anterior maxilla. Imaging examinations revealed a radiolucent, tumor-like solitary lesion. Nuclear medicine scans revealed hyperintense accumulations at the anterior maxilla. Myofibroma was strongly suggested and no malignant finding was observed on biopsy. Since the lesion was solitary, it was excised completely by surgery. The histopathological findings indicated that the lesion mainly comprised bundles of spindle cells with a central hemangiopericytoma-like vascular pattern. Immunohistochemical staining showed the lesion to be positive for vimentin, α-smooth muscle actin and S-100 and negative for desmin. Thus, a definitive diagnosis of myofibroma was made. No recurrence was observed at the 2-year postoperative follow-up. The present case suggests that pathological examination including immunohistochemical analysis is essential for definitive diagnosis and for avoiding misdiagnosis and the consequent unnecessary therapies.