๐ญ๐๐ฐ๐ธ๐ฒ๐ฟ๐ธ๐ฎ๐ป๐ฑ๐ฎ๐น ๐ง๐๐ฏ๐ฒ๐ฟ๐ฐ๐น๐ฒ(๐ญ๐ง):
๐ญ๐ง is a posterolateral projection of the thyroid gland, located adjacent to the junction of the thyroid and cricoid cartilages,is a remnant of ultimobranchial body.
The ZT is present in 70% of individuals and usually is less than 1cm in diameter.
When present, it constitutes a useful anatomical landmark
for identification of the RLN and the superior parathyroid gland.
The ZT has been described as being shaped like an โarrow that points towards the RLNโ.This is because the RLN travels posteromedially to a well developed ZT in more than 80% of people, and in this location the nerve may often be mistaken as travelling intrathyroidally. The RLN may, through gentle dissection and with medial retraction of the ZT, be gradually exposed up to its entry into the larynx.
Like the ZT, the superior parathyroid glands are also derived from the fourth pharyngeal pouch; their common embryological origin explains the consistent posterior & superior location of the superior parathyroid gland in relation to the ZT.
Thus, the superior
parathyroid gland should be routinely identified and its blood supply carefully preserved during thyroidectomy, especially when dissecting the ZT.
๐๐๐: ๐๐ซ๐๐ฒโ๐ฌ ๐๐ฎ๐ซ๐ ๐ข๐๐๐ฅ ๐๐ง๐๐ญ๐จ๐ฆ๐ฒ