Risk-adapted therapy for infantile myofibromatosis in children

Infantile myofibromatosis is characterized by proliferation of benign fibrous tumors arising in skin, subcutaneous tissue, muscle, or bone. Solitary and multicentric forms are described. Few reports are available in the pediatric population.

To improve the knowledge of this rare tumor in infants, the authors present a series of all cases of infantile myofibromatosis treated in their institution over a 9-year period in order to propose treatment guidelines based on their experience and a review of the literature.

The authors report a series of 9 cases, 8 solitary forms and 1 multicentric form with visceral involvement treated from 2000 to 2009. Median age was 10 months (range: 2 days-14 years). Six patients with solitary forms underwent primary surgical resection leading to remission. Only biopsy was performed in 1 case, followed by tumor regression with no recurrence. The last patient with a solitary form was treated by chemotherapy and then surgery allowing remission. The patient with a multicentric form presented complete regression of tumors after 1 year of vinblastine and methotrexate combination chemotherapy.

Infantile myofibromatosis is a rare soft tissue tumor mainly concerning infants. Surgery is the treatment of choice for solitary forms when excision is possible. Close follow-up may be proposed in the case of inoperable sites. In multicentric life-threatening forms, chemotherapy promotes tumor regression and the vinblastine and methotrexate combination is effective with few long-term adverse effects.