Fig. 14.

Ectopic mediastinal goiter in a 73-year-old woman. a) An axial HASTE T2-weighted image shows a well-circumscribed and heterogeneous mass (large arrows) with multiple cystic changes in the anterior mediastinum. Flow voids (arrowheads) are seen in the periphery of the mass. b) An axial diffusion-weighted image (b = 1000 s/mm²) shows slightly high signal intensity of the mass (arrow). c) The mean ADC value within the mass (arrow) was high (1.62 × 10⁻³ mm²/s) on the ADC map. d, e, f) Axial dynamic contrast-enhanced images (a: precontrast; b: 30 sec; c: 180 sec after the start of injection of the contrast material) show a rapid intense enhancement and a washout enhancement pattern of the mass (arrow). No enhancement is seen in cystic changes (arrowheads) in the mass.Diagnosis of ectopic mediastinal adenomatous goiter without connection to the cervical thyroid gland was confirmed by surgery (not shown).