ACCESSORY THYROID GLAND WITH DUAL BLOOD SUPPLY: A RARE VARIATION

Abstract

A rare congenital anomaly of thyroid gland due to developmental defect is accessory or ectopic thyroid gland. Ectopic thyroid refers to the presence of thyroid tissue in locations other than the normal in anterior neck region between the second and fourth tracheal cartilages. Abnormal organogenesis of the thyroid gland leads to morphological variations, such as thyroid dysgenesis, hypoplasia, hemiagenesis and agenesis. The ectopic or accessory thyroid being the most common form of thyroid dysgenesis. Here, we are presenting a case with the accessory thyroid tissue with dual blood supply observed during a routine dissection of a female cadaveric body. The accessory thyroid tissue was in the form of an oval structure about 1.5cm x 3 cm was situated in the midline 2cm above the normally located thyroid gland which was supplied by a branch of lingual artery as well as superior thyroid artery. The accessory thyroid tissue could be asymptomatic or it could present with any disorder affecting the main thyroid gland including malignancy. The significance of this case is to show an anatomical variation in the form of developmental defect during the organogenesis of thyroid along with its clinical implications. Thus, this report highlights the importance of knowing and understanding the normal anatomy of thyroid as well as the anatomical variant that could be immensely beneficial while diagnosing thyroid disorders or carrying out surgical procedures involving thyroid.