Ectopic thyroid tissue: unusual differential diagnosis of cervical paraganglioma.

Ectopic thyroid tissue (ETT) lateral to the midline is rare. Its occurrence in the carotid bifurcation is exceptional. We present a 45 years woman who consulted with a slow growing right cervical swelling. Clinical examination Ultrasonography, contrast enhanced CT and cervical MRI concluded to a paraganglioma. Intra-operatively, the tumor didn't have the characteristic aspect of a paraganglioma. Complete excision was performed. Histology concluded to an ectopic micro-vesicular thyroid adenoma. Previous literature was reviewed to summarize clinical and radiologic characteristics of such rare entity. Despite its rarity, ETT must be included in the differential diagnosis of cervical paraganglioma.