Intrathyroidal lymphoepithelial (branchial) cyst: Sonographic features of a rare lesion

Intrathyroidal lymphoepithelial cysts are rare, and only 15 such cases have been reported, Although sonography has been performed in some cases, the f indings have not been discussed previously. Despite its rarity, the sonogra phic appearances of this lesion are similar to those of other commonly enco untered congenital cystic lesions in the head and neck, such as thyroglossa l duct cysts and second branchial cleft cysts, and this may provide a clue to its diagnosis. We describe the sonographic appearances of intrathyroidal lymphoepithelial cysts.