Multicentric infantile myofibromatosis with extensive involvement limited to bone

Infantile myofibromatosis (IM) is the most common benign fibrous tumor of infancy, characterized by the development of single or multiple nodules in the skin, soft tissues, bone, and/or viscera. Multicentric forms are less frequent and can affect different tissues simultaneously and their prognosis depends on their extension and visceral involvement. Rarely, these forms are limited to the skeleton, in which case the absence of extraosseous lesions makes it difficult to suspect this entity. We present the case of an infant with multiple radiolucent lesions involving the skull, ribs, spine, and long bones, discovered in a radiological study performed after a minor trauma. A broad differential diagnosis was considered based on the osteolytic and polyostotic nature of the lesions on imaging studies. This report details and illustrates the typical radiological findings in bony involvement of IM, which suggest this disorder over other diagnostic options.