Sternocleidomastoid tumor of infancy is the most commonest neck mass found in perinatal period. The term 'tumor' is misnomer as the it is muscle fibrosis and not the tumor. The child usually present with a spindle shaped mass on the lateral aspect of the neck with restriction of neck movements (torticollis). The possible cause of Sternocleidomastoid tumor may be injury to the neck during delivery causing muscle injury and subsequent fibrosis.
It is commonly seen on right side, more in male children & in breech delivery. After clinical examination, ultrasonography is done to confirm the diagnosis. It arises from the middle or inferior portion of the lateral muscle of neck i.e. sternocleidomastoid muscle. The biopsy is not needed unless the USG shows different picture.
Treatment is conservative with physiotherapy of the neck. Passive movements of the neck allows mass to resolve by the age of six months. The indications for surgery are craniofacial asymmetry, persistent torticollis for more than one year and when physiotherapy fails.