1. Radiology Case Presentation Hillel Sternlicht UVA School of Medicine July 18, 2008

2. The Patient 10 yo Female who presents with recurrent otitis media Upon physical exam, pt noted to have mass at base of tongue. Pt herself asymptomatic. Hx only significant for grandfather with hypothyroidism and possible papillary thyroid CA

3. The Differential Thyroglossal duct cyst:U/S demonstrates midline,hypoechoic mass.CT and MRI show uncomplicated cyst with uniform density Lingual Dermoid Cyst: Fatty contents such as fat-fluid level is pathognomonic for dermoid cyst. MR of epidermoid cyst show fluid-filled lesion with hypointense signal on T1 and hyperintense on T2 A slight rim enhancement around these cysts can sometimes be noted. Lingual Thyroid: Hyperdense on post-contrast CT or MRI. On pre-contrast MRI, it may be only slightly hyperintense on both T1- and T2-weighted images. Thyroid scintigraphy is the most definitive non-invasive technique for establishing the diagnosis of thyroid ectopia.

4. Imaging Findings: MRI Round, well circumscribed 2.5 x 2.5 cm mass at midline tongue base, demonstrating intermixed areas of cystic change

5. Imaging Findings: Uptake Scan Increased radiotracer uptake in the region of the tongue base. No significant radiotracer uptake is noted in the expected region of the thyroid bed

6. References Beil CM, Keberle M. Oral and oropharyngeal tumors. Eur J Radiol. 2008;66(3):448-59 Hod N, Mindlin L, etal. Double ectopic thyroid. Pediatr Radiol 2002;32:85-61.

7. Radiology