Thyroid hemiagenesis associated to Basedow-Graves disease. Report of one case

We report a 35 years old female with left lobe thyroid hemiagenesis who ini tially was euthyroid and then developed hyperthyroidism due to Graves disea se. Hemiagenesis of the thyroid gland is a rare anomaly with an uncertain i ncidence; up to now 256 cases have been reported. The detection is often ma de by either clinical symptoms of thyroid dysfunction, by imaginological st udies or surgical/pathological procedures. No explanation has been given fo r the development of this anomaly; left lobe aplasia and predominance of oc currence in women have been most frequently reported.