[Remnants of the thyroglossal duct. A histological study].

This study was undertaken in order to find out the frequency of thyroglossal duct remnants and to specify the relationship between this tract the hyoïd bone. The remnants having undergone cystic pathology refer to tracks edged with an epithelial lining which can be various, associated or isolated, types. Thyroïd follicles may be annexed to this track, in or out of its cystic part. The systematic study of 23 hyoïdal and sub hyoïdal regions of adults exempt of any pathologic remnants allows one to find tracks in 13 cases, that is in every other case. This frequency is higher than the one normally described. These remnants always refer to some thyroïd follicle islands and rarely to an epithelial track. Furthermore, we can sometimes observe the frankly intra hyoïdal situation of the thyroid tissue. This last location is discussed according to embryologic data.