I think with ultrasonography, pay attention to the discontinuity of the capsule image, the presence of central vascularization with a blood flow velocity of more than 30 cm / s, an arteriovenous spectrum with a resistance index of less than 0.50, and hypo-anechogenic sites in the node.

if it looks suspicious take a fineneedle biopsy.

Risk stratification using TIRADS is same whether its used for thyroid gland or for thyroglossal duct/ectopic thyroid tissue.

Any suspicious finding on Ultrasonography (TIRADS - IV/V), do FNAC as told by Werner Furlan.