Infantile myofibroma: a firm, round plaque in an infant.

Infantile myofibroma is a rare fibromatous tumor that is variable in presentation and is frequently mistaken for hemangioma or rhabdomyosarcoma. We describe a 14-month-old boy who presented with multiple, enlarging, firm lesions on the shoulder. Biopsy revealed a proliferation of small spindle cells with myxoid and hyalinized stroma infiltrating into the superficial adipose tissue. We provide a brief review of the clinical presentation, histopathologic features, management, and recent advances in our understanding of this rare condition.