Thyroid Hemiagenesis: A Case Report

Thyroid hemiagenesis is a rare congenital anomaly. It is characterized by the formation of one lobe of the thyroid. The true incidence is unknown. There is no left lobe in 80% of the cases. It is believed that a defect in the downward movement is responsible for the altered lobulation in thyroid hemiagenesis. The general condition of the patient was good and vital signs were stable. Free triiodothyronine was 4.3 pg/mL, free thyroxine 0.9 ng/dL, thyroid-stimulating hormone 2.6 µU/mL, and thyroglobulin was 10.6 pg/mL. Anti-microsomal and anti-thyroglobulin antibodies were negative. Routine hematological and biochemical parameters were normal. The left lobe of the thyroid could not be monitored by ultrasonography. Isthmus thickness was 1.5 mm and the right lobe was 11x9x19 mm. Thyroid scintigraphy was performed but left lobe of the thyroid was not visualized. Genetic analysis was planned for the patient. The patient is being monitored regularly without treatment.