Ectopic thyroid tissue presenting as a new neck mass in a pediatric patient.

Ectopic thyroid tissue is an uncommon, but well-documented condition. We present a case of an ectopic thyroid gland with an atypical presentation as a new neck mass in a 3-year-old female without symptoms of hypothyroidism. Imaging confirmed ectopic thyroid and suggested thyroiditis due to hyperemia and heterogeneity on ultrasound. However, there were no laboratory findings of hypothyroidism. An understanding of anatomy and sonographic features of ectopic thyroid gland allows the radiologist to provide a more accurate differential diagnosis in the setting of a neck mass.