Infantile myofibromatosis

Infantile myofibromatosis is a rare disorder in which one or more noncancerous tumors grow in the skin, bone, muscle and soft tissue, and only rarely in the internal organs. The tumors do not spread to distant sites, but they can grow large enough to press on or damage nearby structures, and a form that involves the internal organs can be life-threatening. Most cases begin in infancy or early childhood, although adult-onset cases are described. The solitary form is the most common and tends to affect males, while the multiple forms are more common in females. Most cases arise without any known cause and without a family history, but rare families carry variants in the PDGFRB or NOTCH3 genes. The disorder was first described as a distinct entity in 1954 by Arthur Purdy Stout, who called it congenital generalized fibromatosis, and the name infantile myofibromatosis was introduced in 1981. Its incidence is estimated at between 1 in 150,000 and 1 in 400,000 live births. Many tumors regress on their own, surgery is the main option for focal tumors, and chemotherapy is reserved for cases that involve the internal organs and cannot be treated surgically. This entry records what the sources state and is not medical advice.