FIGURE 120.14 Second branchial cleft pit that had an underlying sinus tract The combination of torticollis and a lateral neck mass in early infancy is highly suggestive of a sternocleidomastoid tumor (nonmalignant) or fibromatosis colli of infancy that can be associated with primiparous births, breech presentations, and difficult labor Clinically, a nontender, firm, ovoid 1- to 3-cm mass is found along the inferior or middle third of the sternocleidomastoid muscle The mass represents local muscle hemorrhage or infarction that subsequently undergoes fibrosis It is believed to be the result of traumatic extraction of the head during delivery or secondary to fibrous dysplasia related to intrauterine positioning While some are noted at birth, others become apparent within the ensuing few weeks The head and ear bend toward, and the chin away from, the affected sternocleidomastoid, and limitation of bending to the opposite side and rotation toward the involved side are noted Initial treatment consists of passive stretching