An incidence study on thyroglossal duct cysts in adults.

Objective: To investigate the incidence of the asymptomatic thyroglossal duct anomalies and to review the literature and make comments on the significance of this condition.

Methods: A total of 80 cadavers were dissected in the present study. This study was carried out during 2005, where the cadavers were randomly included from the criminal laboratories of the Ministry of Justice, Republic of Turkey in Istanbul. None of the cadavers had laryngeal and cervical injuries resulting from a trauma or the cause of their death. The examined cadavers included 59 men and 21 females, and their age were ranged from 35-80 years old. The larynges were removed and fixed in 10% formalin and then dissected. The sections were examined using surgical SMZ 10 Nikon stereomicroscope. We evaluated the presence, localization, and diameter of the cysts with regard to age and sex of the cadavers.

Results: We observed a total of 12 different localization of thyroglossal ducts and cysts among the dissected 80 cadavers. Ten of these ducts cysts were found in males with an age range of 35-68 years and 2 in female cadavers aged 46-65 years. In 6 cases, the thyroglossal ducts and cysts were located in the left of the midline of the neck, while 3 cases were from the right of the midline, and the remaining was located on the midline of the neck. In all cases, thyroglossal ducts and cysts were complete and restricted to the infrahyoid region; all of them had connection with the hyoid bone, but not with the perichondrium of the cartilage. In addition, the thyroglossal ducts had connection with the left lobe of the thyroid glands in 3 cases, one case in the right lobe, and 2 cases with the isthmus of the thyroid gland. Finally, in 5 cases thyroglossal ducts were complete and had well-developed cysts.

Conclusion: Thyroglossal duct remnants are one of the most often seen congenital asymptomatic masses of the neck region (7%). The presence of these duct remnants may lead to abnormal phonation and epithelial carcinomas. Therefore, correlation of the rate of thyroglossal duct remnants in a population together with the related clinical symptoms can lead to an early diagnosis and better treatment chances for these problems.