Infantile myofibromatosis: a series of 28 cases.

Background: Infantile myofibromatosis (IM) is a rare disorder of fibroblastic/myofibroblastic proliferation in children.

Objectives: We sought to document common and unusual characteristics of patients with IM.

Methods: This was a retrospective study of 28 children diagnosed with histopathologically confirmed IM between 1992 and 2012. Epidemiologic, clinical, and treatment data were reviewed.

Results: IM was more frequent in boys (60.8%). Skin lesions were congenital in 64.3% of cases. The solitary form accounted for 50% of cases. Most nodules were painless, arising in cutaneous or subcutaneous tissue. The multicentric form accounted for 39% of cases; the skin, subcutaneous tissue, or muscle was involved in 97.8% of cases, and the bones in 50% of cases. The generalized form had a mortality rate of 33% (one-third of cases). Multicentric and generalized forms regressed spontaneously; severe local complications were observed, and late recurrent nodules developed in a few cases.

Limitations: The retrospective review and the ascertainment of patients (from the departments of obstetrics and pediatrics) may have introduced bias in the analysis of severity of the different forms of IM.

Conclusion: The diagnosis of IM must be confirmed histopathologically because the clinical presentation can be misleading. The prognosis is usually good, although local morbidity can occur. The generalized and multicentric forms merit long-term follow-up.