Fibromatosis colli is a benign fibrous mass developed from the sternocleidomastoid muscle. The exact etiologies are unknown. It seems that it is due to birth trauma. Ultrasound is the diagnostic tool of choice. The treatment is based on physiotherapy.
Congenitalcervical anomalies are important to consider in the differential of head and neck masses in children and adults. These lesions can present as palpable cystic masses, infected masses, draining sinuses, or fistulae.