The sternocleidomastoid tumor of infancy.

The sternocleidomastoid tumor of infancy is an uncommon clinical entity which has received little attention in the otolaryngological literature. The diagnosis must be considered in any infant presenting with a lateral neck mass. Although its natural history favors spontaneous regression, the mass may initially grow in size. The purpose of treatment is the prevention of torticollis and craniofacial asymmetry. The initial treatment is non-surgical, passive and active exercises. Only when this treatment fails should surgery be performed. The disappearance of the lesion is not always a predictable sign. A small number of children will develop delayed torticollis or craniofacial asymmetry. It is important that parents be informed of this possibility and of the necessity for long term follow-up.