Clinical Presentation

An infant with a mass in the mouth.

Further Work-up

(A) Sublingual ultrasound (US) findings: there is a well-circumscribed, round, homogeneous mass (arrow). (B) Doppler US findings in the neck: there is no normal thyroid tissue in the thyroid bed (arrows). (C) Pertechnetate nuclear medicine study: there is uptake of pertechnetate at the base of the tongue (arrows).

Differential Diagnosis

• Lingual thyroid: