Fibromatosis colli: a rare case report

Abstract

Fibromatosis colli, a rare benign congenital mass of the sternocleidomastoid muscle, is mainly found in the neonatal age group, often at the age of 2 to 4 weeks of life. Also known as a pseudo tumour, its aetiology is still unknown and may occur due to injury of the sternocleidomastoid muscle in the last trimester of intrauterine life or during delivery. Frequently manifests as restriction of neck movement and enlarging neck mass at around 14-28 days after birth. Ultrasonography (USG) neck is the preferred diagnostic modality. Treatment is mainly conservative consisting of observation and stretching exercises. Surgical intervention is required in <10% of cases and consists of a tenotomy of the sternocleidomastoid muscle. We present a case report of fibromatosis colli in a 15-day-old female neonate with a history of birth trauma presented with a right neck mass and torticollis, diagnosed using high-frequency ultrasound. This condition regressed in the next few months while the patient was instituted only conservative treatment. Thus, signifying the importance of clinical diagnosis and differentiation from other causes of neck masses to prevent unnecessary investigation and overtreatment.