Fibromatosis Colli: A Rare Cervical Mass. Case Report from Sédhiou (Senegal) and Review of the Literature

Fibromatosis colli is a rare disorder of the sternocleidomastoid muscle (SCM) in newborns and infants. Although the etiology is unknown, it seems to be linked to an ischemia of the muscle related to an obstetric trauma. Its estimated incidence is 0.4% of births associated with male predominance. We report the case of a one-month-old female infant with a non-inflammatory right laterocervical swelling that had been present for a fortnight after birth. Ultrasound confirms the diagnosis. Conservative treatment by physiotherapy has enabled a favorable development. This rare case illustrates the importance of positive diagnosis based on clinical and ultrasound examination to avoid unnecessary invasive acts of the neck in infants.