Post-stress rebound hyperplasia may occur following recovery from severe infections, chemotherapy, steroid therapy, or radiation, where the thymus re-expands rapidly as part of immune system recovery [5] Graves’ disease, although rare in children, has been reported as a cause of thymic enlargement due to thyrotropin receptor stimulation, and this enlargement is often reversible with the treatment of hyperthyroidism [7]. This evidence concerns the gene TSHR and hyperthyroidism.