[Familial infantile myofibromatosis]

International audienceBACKGROUND: Infantile myofibromatosis (IM) is the most common fibrous disorder of infancy and childhood. It is characterized by congenital tumours of the skin, striated muscle, bones and viscera. Most cases are sporadic and few familial cases have been reported. PATIENTS AND METHODS: We describe a 5-month-old girl presenting with two congenital nodules. The diagnosis of infantile myofibromatosis was based on clinical and histopathological examination. Surgical excision was performed and there was no relapse at six years. The patient's brother presented multiple nodules and toe necrosis at birth due to infantile myofibromatosis. Two months later, the congenital nodules increased in size and new nodules developed. Surgical excision was performed. At 11 months of age, the boy presented with cranial relapse and bone resorption at P3 of the third right toe. The clinical and radiological investigations were normal. DISCUSSION: Three clinical forms of IM have been described: solitary cutaneous nodules, multiple cutaneous nodules and generalized MI with visceral involvement. The prognosis is good except in generalized MI. All familial cases of MI may be interpreted as autosomal dominant or alternatively there may be genetic heterogeneity. Strict follow-up is recommended to identify potentially life-threatening complications. Spontaneous regression usually occurs but in some cases the treatment of choice is surgical removal