Infantile myofibromatosis: unusual diagnosis in an older child.

This manuscript describes the unusual presentation of infantile myofibromatosis (IM) in an older child with its diagnosis and management. An 8-year-old girl presented with a painless, rapidly expanding malar mass. CT demonstrated an erosive soft tissue lesion and needle biopsy was nondiagnostic. Complete excision returned the pathologic diagnosis of IM. The patient had no complications and no evidence of recurrence at 1 year. Almost 90% of IM cases present by age two and IM in older children is highly unusual. The solitary form of IM is most common and its treatment is complete excision with an excellent prognosis.