Fibromatosis Colli on Point of Care Ultrasound (POCUS): A Case Report.

Fibromatosis colli is a rare benign fibrosis of the sternocleidomastoid (SCM) muscle which manifests clinically as congenital muscular torticollis, or an ipsilateral head tilt with contralateral turning of the neck. Though benign, care must be taken not to miss other etiologies with similar clinical presentations, such as malignancies or abscesses. Point of care ultrasound (POCUS) offers a rapid, low-cost, and accessible option for adjunct imaging. In this case report, a 26-day-old boy presented to the pediatric emergency department for evaluation of a nontender, firm left-sided neck mass with preferential turning of his head to the right. POCUS showed a noncompressible, homogenous, well-defined mass in the left SCM without increased vascularity consistent with fibromatosis colli. The patient was discharged from the emergency department with outpatient follow-up. His follow-up course required no further imaging or testing, and the patient's symptoms resolved with physical therapy.