This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Fibromatosis colli

Fibromatosis colli is a rare form of infantile fibromatosis that occurs within the sternocleidomastoid muscle 4.

The importance of fibromatosis colli, above all else, is that it must be recognised for the benign lesion that it is. Presentation is usually with torticollis, and is most frequently related to birth trauma (e.g. forceps delivery) or malposition in the womb. It is unilateral in most cases.


There may be a slight male predilection. It typically presents a few weeks after birth.

Radiographic features


Ultrasound is the imaging modality of choice. The sternocleidomastoid is diffusely enlarged in a fusiform manner, with resultant shortening and therefore head turned away from the affected side (mastoid process drawn down towards the ipsilateral head of clavicle). Echogenicity may vary. Colour Doppler interrogation may reveal a high resistance waveform. The enlarged area often moves synchronously with the rest of the SCM muscle on real time sonography 1.


Typically shows a diffusely enlarged sternocleidomastoid muscle which is iso attenuating to normal neighbouring musculature. Adjacent fat planes are well preserved. At times calcification may be present 2.

Treatment and prognosis

It is a self limiting condition and usually resolves within 4-8 months 3 and requires no more than physiotherapy.

Differential diagnosis

For a general differential see: differential diagnosis of paediatric cervical lesions

Updating… Please wait.


Error Unable to process the form. Check for errors and try again.

Alert_accept Thank you for updating your details.