Agenesis of isthmus of thyroid gland in adult human cadavers: a case series.

The thyroid gland, a highly vascular endocrine 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. In our study, on the morphometric features of the thyroid gland it was found that, 6 out of 41 thyroid glands that were dissected, showed an absence of the isthmus. The respective lateral lobes were positioned independently on either side of the trachea. The incidence of agenesis of isthmus, along with the developmental and clinical significance are discussed herein under.