CT and MRI findings of developmental abnormalities and ectopia varieties of thyroid gland

Cause inhabituelle de dyspnée chez l’enfant

“…La TDM et l'IRM ne trouvent leur intérêt que lorsque l'écho-graphie ne retrouve pas de thyroïde ectopique. En TDM, le parenchyme ectopique prend l'aspect d'une formation de densité tissulaire se rehaussant de façon intense, tandis qu'en IRM, il apparaît en hypersignal T1 et T2 par rapport aux muscles adjacents [7]. L'angiographie est de moins en moins utilisée, du moins à but diagnostique, toutefois elle peut, en imagerie interventionnelle, constituer un premier temps thérapeutique par embolisation préopératoire.…”

Ectopic thyroid tissue presenting as a cardiac mass

“…The thyroid gland derives from a midline thickened out pouching of the endodermal epithelium of the pharynx between pharyngeal pouches 1 and 2, directly dorsal to the aortic sac (2,11). In the early stages, the thyroid is in close proximity to the bulbus cordis, from where the right heart develops.…”

“…As a result, lingual thyroid is the most frequent, occurring in 90% of cases. Surpahyoid, infrahyoid, submandibular, tracheal, lateral cervical, axillary, palatine tonsils and the bifurcation of the carotid artery are all locations in the head and neck region that have been reported to contain ectopic thyroid tissue (2,5). Ectopic thyroid tissue has also been reported at more distant sites in the liver, duodenum, jejunum, pancreas, porta hepatis, gallbladder, stomach, adrenal gland, aorta and oesophagus (4,5,10) explained, most likely, by over-descent of the thyroid during embryogenesis.…”

“…Primary cardiac tumours are rare, usually benign lesions with an overall incidence of 0.05-0.5% (1,2). The most common form of primary cardiac tumour, accounting for 25% of cases, is a myxoma, a pedunculated tumour arising from the endocardium (3).…”

Lingual Thyroid

“…However, the use of eight-channel surface coils for high-resolution MRI can allow adequate evaluation of the thyroid gland and entire neck. Scintigraphic imaging using iodine-131 (I-131) and/or technetium-99 (Tc-99) provides highly sensitive image in patients with ectopic thyroid tissue and scintigraphic imaging modalities offer the possibility of whole-body evaluations [44]. Fine needle aspiration cytology (FNAC) also provides support in confirming the diagnosis of ectopic thyroid.…”