A sternocleidomastoid tumor, medically known as fibromatosis colli, is a benign (non-cancerous) swelling that develops within the sternocleidomastoid muscle of the neck. This muscle runs along the side of the neck and helps in head movement and rotation. The condition is most commonly seen in newborns and young infants.
Despite the term “tumor,” this condition is not cancer. It is a localized swelling caused by fibrosis (thickening) of the muscle tissue.
The exact cause is not always clear, but it is often associated with:
Difficult or prolonged labor
Birth trauma
Assisted delivery (forceps or vacuum)
Abnormal positioning of the baby in the womb
These factors may lead to minor injury or reduced blood supply to the neck muscle, resulting in swelling and muscle thickening.
Parents may notice:
A firm, painless lump on one side of the baby’s neck
Limited neck movement
The baby tilting the head to one side (torticollis)
Preference to look in one direction
The swelling usually appears within the first few weeks of life and gradually becomes noticeable.
Diagnosis is typically made through:
Clinical examination by a pediatric surgeon or pediatrician
Ultrasound of the neck (to confirm muscle thickening and rule out other causes)
Advanced imaging is rarely required.
In most cases, sternocleidomastoid tumor does not require surgery. The primary treatment is:
Gentle neck stretching exercises
Physiotherapy to improve neck movement
Parental guidance on positioning techniques
With early physiotherapy, most infants show significant improvement within a few months. The swelling gradually reduces as the muscle heals.
Surgical intervention is very rarely required. It may be considered only if:
The condition persists beyond one year
Severe neck stiffness does not improve with therapy
There is significant cosmetic deformity
Most children recover completely with non-surgical treatment.
Early diagnosis and timely physiotherapy prevent complications such as persistent torticollis or facial asymmetry. If you notice a neck swelling or abnormal head position in your infant, prompt medical consultation is recommended.
Our pediatric team provides careful evaluation and personalized treatment for sternocleidomastoid tumors. With early intervention, expert physiotherapy guidance, and continuous parental support, we ensure optimal recovery and healthy neck development for your child.
