Abdominal para-aortic ectopic thyroid tissue mimicking lymphadenopathy on computer tomography

The lesionsshowing mild increased attenuation on pre-contrast imagesand vivid heterogenous enhancement on post-contrastimages. (c) Axial fluorodeoxyglucose-18 positron emissiontomography-computed tomography demonstrating mildmetabolic activity over the lesions (maximum standard unitvalue=2.6) The CT-guided biopsy of the para-aortic lesions subsequently showed cuboidal follicular cells arranged in architecture resembling thyroid parenchymal tissue (Fig 2). Corresponding (c) axial and (d) coronal computed tomography fusion imagesshowing the left para-aortic lesions Figure 4. (a) Thyroid scintigraphy image and (b) correspondingcomputed tomography fusion image showing the presenceof orthotopic thyroid gland, with a focal defect at the lowerpole corresponding to a cold nodule Ectopic thyroid gland is a rare developmental abnormality with a prevalence of approximately 1 per 100 000 to 300 000 population.1 It results from aberrant embryogenesis of the gland during its migration from the foramen cecum at the posterior aspect of the tongue to its final pretracheal position. To the best of the authors' knowledge, this is the first report of ectopic thyroid tissue occurring at the para-aortic region of the abdomen, mimicking the appearance of lymphadenopathy on CT.