In infants and children, cervical masses originate from a variety of p
athologic, congenital and developmental conditions, and it is importan
t to distinguish benign from serious lesions. Fibromatosis colli is a
rare cervical lesion that typically presents in the neonatal period. I
t is the most common cause of neonatal torticollis and should be recog
nized by physicians caring for neonates and infants.