The thyroid gland is composed of two lateral lobes connected by a narrow median isthmus, thus giving an ‘H’ shaped
appearance to the gland. A wide range of morphological variations and developmental anomalies of the thyroid gland have
been reported in the literature such as hypoplasia, ectopic thyroid, hemi-agenesis and agenesis. Out of these, the incidence
of agenesis of the isthmus of thyroid gland is rare. During routine dissection of the male cadaver, agenesis of isthmus of
thyroid gland in the midline was noted. The arteries supplying the gland were confined only to the respective lobe with
absence of anastomosis. Agenesis of isthmus of thyroid has clinical, phylogenetic and surgical significance. The knowledge
of various developmental anomalies of the gland and variations in neurovascular relations will help the surgeon in better
planning of a safe and effective surgery.
agenesis, anomaly, thyroid, thyroglossal duct, thyroid isthmus.