Dessie Meselech Ambaw
Department of Anatomy, School of Medicine, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia.
Anat Cell Biol. 2018 Dec;51(4):243-250. doi: 10.5115/acb.2018.51.4.243. Epub 2018 Dec 29.
Because of its embryonic origin, the thyroid gland is predisposed to multiple anatomical variations and developmental anomalies. These include the pyramidal lobe, the origin of levator glandular thyroidae, the absence of the isthmus, ectopic thyroid, accessory thyroid tissues, etc. These anatomical variations are clinically significant to surgeons, anatomists, and researchers. The present study was designed to report anatomical variations and developmental anomalies of the thyroid gland in Ethiopian population. The study was conducted on 40 cadavers used for routine dissection classes. The thyroid gland was exposed and observed for any variations and developmental anomalies. The length, width, and thickness of the lobes were measured using a vernier caliper. Differences in the incidence of pyramidal lobe and absence of the isthmus between sexes were tested using a Pearson chi-square test. The mean length, width, and thickness of the right lobe were 4.24 cm, 1.8 cm, and 1.6 cm, respectively, whereas it was 4.08 cm, 1.8 cm, and 1.6 cm, respectively for that of the left lobe. The pyramidal lobe was noted in 52.5% of the cadavers. The levator glandulae thyroidae were prevalent in 40% of the cadavers. The isthmus mainly overlies the 2nd to 4th tracheal rings and was absent in 7.5% of the cadavers. Accessory thyroid tissue and double pyramidal lobes were noted in 2.5% of the cadavers. Most of the variations of the thyroid gland were seen frequently in female but it was not statically significant. Different clinically important and rare variations of the thyroid gland were found.
由于其胚胎起源，甲状腺易出现多种解剖变异和发育异常。这些包括锥体叶、甲状腺提肌的起源、峡部缺如、异位甲状腺、副甲状腺组织等。这些解剖变异对外科医生、解剖学家和研究人员具有临床意义。本研究旨在报告埃塞俄比亚人群中甲状腺的解剖变异和发育异常。该研究对40具用于常规解剖课程的尸体进行。暴露甲状腺并观察有无变异和发育异常。使用游标卡尺测量叶的长度、宽度和厚度。使用Pearson卡方检验测试两性之间锥体叶发生率和峡部缺如的差异。右叶的平均长度、宽度和厚度分别为4.24厘米、1.8厘米和1.6厘米，而左叶分别为4.08厘米、1.8厘米和1.6厘米。在52.5%的尸体中发现了锥体叶。甲状腺提肌在40%的尸体中普遍存在。峡部主要覆盖第2至第4气管环，7.5%的尸体中峡部缺如。在2.5%的尸体中发现了副甲状腺组织和双锥体叶。甲状腺的大多数变异在女性中更常见，但无统计学意义。发现了不同的具有临床重要性和罕见的甲状腺变异。
