[Dual ectopic thyroid: subclinical hypothyroidism after extirpation of a submaxillary mass].

Ectopic thyroid tissue is a rare clinical entity, and more so when it is present in two different locations. We present the case of a 38-year-old euthyroid woman with submandibular and lingual ectopic thyroid tissue in the absence of a normally located thyroid gland, diagnosed after the extirpation of an asymptomatic mass misdiagnosed as a neoplasm of the submaxillary gland. Despite its low frequency, the possibility of ectopic thyroid should be considered when making a differential diagnosis of neck masses, using ultra-sound, thyroid scan and ultrasound-guided fine-needle aspiration biopsy.