[Myofibromatosis in children. Histopathologic and ultrastructural study of a localized form with a spontaneously...

Report of a case of the localized form of infantile myofibromatosis, in a three-month-old boy with a brachial mass and osteolytic lesion of the adjacent humerus at radiographic examination. Diagnosis is made on the histopathological features of the lesion at biopsy. Ultrastructurally, the tumor cells have myofibroblastic differentiations. Evolution is regressive without any treatment. The anatomical, clinical, pathological, ultrastructural and evolutive features are discussed.