[Voice change and laryngeal obstruction caused by a median thyroglossal duct cyst].

Thyroglossal duct cysts are common primary neck tumors, resulting from remnants of the ductus thyroglossus. They can occur at any point along the migratory path of the thyroid gland anlage until the 2nd or 3rd decade of life. The usual symptoms leading to the diagnosis are painless midline neck masses orfistulas. Despite their close proximity, the cysts normally do not affect the larynx. We report on the eighth case mentioned in the world literature of a thyroglossal duct cyst invading the larynx in a 62-year-old patient. Preoperatively, the voice of the patient sounded metallic, and the frequency of the voice field was reduced. Postoperatively, the voice onset was physiological, and the voice increased by an octave in the higher frequencies. The intonation of the voice was steady. The analysis of formants of the vowels "a" and "i" showed that the fourth formant of the vowel "i" was lower in frequency postoperatively.