Tag Archive for: Agenesis

The thyroid gland is composed of two lobes connected by an isthmus that traverses the midline of the upper trachea between the second and third tracheal rings. The most common manifestation of dysgenesis of the thyroid gland is hemi agenesis or ectopic thyroid gland tissue. Specifically, the incidence rate of agenesis of the thyroid isthmus ranges between 0.5 and 10%. Remember that the identification of agenesis of the isthmus and other thyroid anomalies during preoperative evaluation of patients scheduled for thyroid surgery would significantly contribute to safer surgical procedures and fewer complications. We present a patient with an enlarged right thyroid nodule on USG who was scheduled for a right hemithyroidectomy but was ultimately diagnosed intraoperatively with thyroid isthmus agenesis.