ACCESSORY THYROID GLAND OF THE LATERAL NECK

Abstract

To the Editor, A 34-year-old Turkish woman presented with a left-sided cervical accessory thyroid gland. Her B-Mode thyroid ultrasonography exhibited an accessory thyroid parenchyma adjacent to the inferolateral border of left lobe of the thyroid gland (Figure 1a). fine-needle aspiration (FNA) cytology (FNAC) is a frequently used primary diagnostic procedure worldwide due to its preciseness, easiness, non-invasiveness, possessing very little complications and low cost [1, 2]. The thyroid gland ectopia and accessory thyroid tissue are two patterns of the abnormal thyroid gland migration. Ectopic thyroid gland is rare phenomenon and described as a functioning thyroid tissue in an aberrant area along the embryological descending line of the thyroid gland. Its most common form is known as lingual thyroid, accounting for 90 %. Aproximately 70 % of patients will exposed to the hormonal status of sub-clinical hypothyroidism [3]. These phenomenon may later undergo a malignant transformation [4]. An accessory thyroid gland is determined as a permanence of the thyroidal parenchyma anywhere from the base of the tongue to the thyroid isthmus, with the majority of the functional thyroid in its normal pre-tracheal area. The incidence of accessory thyroid gland is unknown [3]. Of 58 cadavers just one (1/58) was detected as the accessory thyroid gland on the thyroid cartilage by Braun et al [3]. Radkowski et al [5] performed thyroid US on 230 cases of the throglossal duct cyst and detected four cases (4/230) with the accessory thyroid tissue and three (3/230) with the ectopic thyroid gland. Therefore, they propunded the possibility of their equality in the incidence. The accessory thyroid glands are classified into five groups, based on their anatomical location: (1) cranial, (2) caudal, (3) lateral, (4) ventral, and (5) dorsal glands. They usually are founded along the former course of the thyroglossal duct and emigrate laterally [6]. Pyramidal lobes, superior accessory thyroids, retrotracheal, inferior/lateral extensions or extrusions are involved in the reasons of the recurrent thyroid diseases as the anomalies of the gland. Richards et al [3] asserted both thyroid gland ectopia and accessory thyroid tissue being vulnerable to the same potential diseases as a normally-situated thyroid gland. An accessory thyroid gland do not lead to clinical complication except in cases of the pathologic conditions such as goitre, malignancy, and the others. A thyroid FNA were planned, performed and its cytopathological evaluation with Haematoxylin and Eosin revealed a huge cellular cluster including the benign thyrocytes (Figure 1b). Therefore, a clinical follow-up was suggested for the present case, after a benign FNAC. Conclusively, education, training, and cognition of the thyroid anatomy and its associated variations and anomalies are very much essential for these kinds of the cases and it will lead to increasing the level of awareness.