Myofibroblastoma of the mandible in a 3-year-old child

Myofibroblastoma is a rare benign tumor of the head and neck region, which is characterized by a large, rapidly growing, and destructive mass. A 3-year-old boy presented with an 8-week history of a rapidly growing swelling of the right mandible. Examination revealed a firm 13-cm mass occupying the entire right body and ramus of the mandible. The clinical and radiological features were suggestive of a sarcoma. An initial biopsy taken in the referring hospital was inconclusive, and the second biopsy showed a myofibroblastic neoplasm consistent with a desmoplastic fibroma. Progressive tumor growth necessitated a tracheostomy. Right hemimandibulectomy was performed, and the defect was reconstructed with free microvascular fibula flap. Histopathology and immunocytochemistry revealed a myofibroblastoma. This entity differs from other myofibroblasts and fibroblast tumors such as inflammatory myofibroblastic tumor (IMT), myofibroma, and desmoplastic fibroma. The child has been followed up for 2 years.

Differentiation between myofibroblasts and fibroblastic tumors as well as some malignancies can be challenging. Myofibroblastoma can behave as a malignant neoplasm, and the clinical distinction of this entity lies primarily in its recognition as a benign neoplasm.