Abstract:
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
