Summary

Neck masses are a common yet challenging presentation in pediatric patients. They may be caused by congenital, inflammatory, neoplastic, or vascular issues. The diverse nature of these masses can make definitive diagnosis difficult for clinicians. Several classification systems exist to categorize neck masses, considering factors such as age at presentation, anatomical location, imaging characteristics, and underlying etiology [1].

These masses often reflect benign infectious, inflammatory, or congenital etiologies. However, in certain cases, lymphadenopathy or other neck masses may indicate an underlying malignancy, thereby serving as a significant source of anxiety for patients and their families.

Fibromatosis colli (FMC) is characterized by a diffuse enlargement of the sternocleidomastoid muscle (SCM), usually in infancy. FMC, initially described as SCM tumors in childhood, is detected in 0.4% of live births but is among the most frequent perinatal neck masses [2].