Radiologic-Pathologic Correlation of Unusual Lingual Masses: Part I: Congenital Lesions

lthough the vast majority of lingual masses are squamous cell carcinomas, a variety of congenital lesions may affect the tongue.These usually manifest as a submucosal bulge and are located in a deep portion such as its base.Thus, the characteristics and extent of these lesions may be recognized only on cross-sectional CT or MR images.In this article, we describe the imaging findings of congenital lingual masses, provide clinical and pathologic-radiologic correlation, and discuss the role of CT and MR imaging in the diagnostic work-up of these lesions. Lingual thyroidEmbryologically, failure of the thyroid gland to separate from the base of the tongue results in a lingual thyroid, which accounts for 90% of ectopic thyroids.Remnant thyroid tissue can be demonstrated at the base of the tongue in up to 10% of autopsy specimens (1).Most cases are asymptomatic but symptomatic patients have dysphagia (50%), dysphonia (44%), or dyspnea (28%).Malignancy in lingual thyroid is rare.Lingual thyroid has an absolutely characteristic CT appearance: its iodine content causes it to have very high attenuation values in relation to surrounding soft tissue.The mass of ectopic thyroid tissue usually lies in the center of the tongue base within intrinsic muscle; intravenous contrast enhancement will increase the differential density between thyroid tissue and surrounding musculature (Fig. 1).Rarely, a lingual thyroid has been found to show inhomogeneous contrast enhancement on CT, resulting from