Congenital Fibromatosis Colli: A Rare Cause of Neck Swelling with Clinicopathological Pointers

Abstract

Fibromatosis Colli or congenital fibromatosis Colli (also known as sternocleidomastoid tumour or pseudotumour) is a rare benign lesion affecting the sternocleidomastoid muscle that manifests in the first few weeks of life and may be associated with muscular torticollis. It is seen in infants following difficult delivery and usually appears as a well-circumscribed, firm to hard, immobile, fusiform swelling in the mid or distal one-third of the sternocleidomastoid muscle. It should be differentiated from more common causes of lateral neck masses including inflammatory, congenital, and neoplastic conditions. The disease is diagnosed using typical clinical presentation and fine needle aspiration cytology, however, radiological investigation like ultrasound scan and Computed Tomography scan can help in ruling out other differential diagnosis especially in atypical clinical presentation. We present a case of neck mass that should be born in mind when evaluating young infants with neck swelling.