Right-sided thyroid hemiagenesis with enlarged isthmus and lingual ectopic thyroid tissue presenting as nodular goiter: case report and literature review.

Introduction And Importance: Thyroid hemiagenesis (THA) is a very rare congenital anomaly defined by the underdevelopment or complete absence of one thyroid lobe. Similarly, ectopic thyroid tissue (ETT) is a rare condition where thyroid tissue is located outside its usual anatomical position, most often at the tongue base. The simultaneous occurrence of THA and ETT is extremely rare, as demonstrated in our case.