Infantile Myofibromatosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Infantile Myofibromatosis?
A primary care doctor usually starts the evaluation and refers the family to the right specialists. Treatment often involves a pediatric surgeon, and it can also involve a geneticist. Sometimes it involves a cancer specialist called an oncologist. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Infantile myofibromatosis is a rare condition in which small growths called myofibromas form in a baby's skin, muscles, or organs. A myofibroma is a lump made of cells that look a bit like both muscle cells and scar tissue cells. These growths are not cancer and do not spread the way cancer does. In many children, the growths shrink or disappear on their own over time.
Symptoms
The most common sign is a firm lump under the skin, often on the head, neck, or trunk. The lump usually does not hurt. Some babies have a single growth, while others have several. When growths form inside organs such as the lungs, heart, or digestive tract, they can cause more serious problems.
Causes and who gets it
In most cases, the cause is not known. Some cases are linked to a changed gene, such as the PDGFRB gene, which can run in families. The condition is usually present at birth or appears in the first two years of life, and it affects boys and girls about equally.
How doctors diagnose it
Doctors start by examining the lump and asking about the child's health history. Imaging tests such as ultrasound, MRI, or CT scans show how many growths there are and whether organs are involved. A biopsy confirms the diagnosis.
Treatment
Many growths need no treatment because they shrink or disappear on their own. Doctors often watch the child closely with regular checkups and imaging. Surgery may remove growths that are large, painful, or pressing on organs. In rare cases where growths affect important organs, medicines such as chemotherapy drugs may be used to shrink them.
When to see a doctor
See a doctor if you feel a firm lump anywhere on your baby's body. Get medical care quickly if the lump grows fast, seems painful, or the baby has trouble breathing or feeding. Any baby with a diagnosed growth should keep all follow-up appointments.
How a direct primary care or concierge doctor fits in
A direct primary care doctor is paid a flat monthly fee instead of billing insurance for visits. A concierge doctor usually charges more and often works alongside insurance. Either one can examine a lump, order imaging, and coordinate referrals to specialists. Because the condition is rare, these doctors usually refer the child to a pediatric specialist.
Common questions
Is infantile myofibromatosis cancer?
No. The growths are not cancer and do not spread through the body the way cancer does. However, growths inside organs can still cause serious problems, so doctors check carefully.
Will the lumps go away on their own?
Many growths in the skin shrink or disappear over months or years without treatment. This does not happen for every child, so doctors monitor each case.
Can it come back after treatment?
Growths can return in some children, especially if they were not fully removed. Regular follow-up visits help doctors spot any new growths early.
Will my other children get it?
Most cases happen by chance and are not passed down. When a changed gene runs in a family, a geneticist can test family members and explain the chances.
Sources
- NIH Genetic and Rare Diseases Information Center - Infantile myofibromatosis
- National Organization for Rare Disorders - Infantile Myofibromatosis
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
