Kyste du tractus thyréoglosse

A thyroglossal cyst is a fibrous cyst that forms from a persistent thyroglossal duct. Thyroglossal cysts can be defined as an irregular neck mass or a lump which develops from cells and tissues left over after the formation of the thyroid gland during developmental stages. Thyroglossal cysts are the most common cause of midline neck masses and are generally located caudal to (below) the hyoid bone. These neck masses can occur anywhere along the path of the thyroglossal duct, from the base of the tongue to the suprasternal notch. Other common causes of midline neck masses include lymphadenopathy, dermoid cysts, and various odontogenic anomalies. Thyroglossal cysts develop at birth. Many diagnostic procedures may be used to establish the degree of the cyst. Thyroglossal duct cysts most often present with a palpable asymptomatic midline neck mass usually below [65% of the time] the level of the hyoid bone. The mass on the neck moves during swallowing or on protrusion of the tongue because of its attachment to the tongue via the tract of thyroid descent. Some patients will have neck or throat pain, or dysphagia. The persistent duct or sinus can promote oral secretions, which may cause cysts to become infected. Up to half of thyroglossal cysts are not diagnosed until adult life. The tract can lie dormant for years or even decades, until some kind of stimulus leads to cystic dilation. Infection can sometimes cause the transient appearance of a mass or enlargement of the cyst, at times with periodic recurrences. Spontaneous drainage may also occur. Differential diagnosis are ectopic thyroid, enlarged lymph nodes, dermoid cysts and goiter. Thyroglossal cyst usually presents as a midline neck lump (in the region of the hyoid bone) that is usually painless, smooth and cystic, though if infected, pain can occur. There may be difficulty breathing, dysphagia (difficulty swallowing), or dyspepsia (discomfort in the upper abdomen), especially if the cyst becomes large.