Bilateral sternocleidomastoid tumors of infancy

The sternocleidomastoid tumor of infancy (STOI) is a relatively uncommon condition. Typically, it presents as a firm, well circumscribed mass within the sternocleidomastoid muscle (SCM) in infants 1-8 weeks of age and may be associated with torticollis. This condition must be considered in any infant with a lateral neck mass. The diagnosis can often be made clinically, but unusual presentations may present diagnostic challenges. Although bilateral involvement is rare, it does occur. The second reported case, a 2-week old female with bilateral STOIs and torticollis, is reported. Although many of the characteristics of the masses suggested the condition, the bilateral nature added uncertainty to the clinical impression, and magnetic resonance imaging (MRI) was used to confirm the diagnosis. The clinical presentation and management of the STOI are reviewed, and the unusual features of this case are discussed.