Differentiated thyroid cancer( DTC ) is characterized by the activity of multitargeted tyrosine kinase inhibitors( TKIs ) of the vascular endothelial growth factor receptor( VEGFR ) pathway. Lenalidomide showed some initial efficacy in DTC, but it is unknown whether it will be safe or effective when combined with VEGFR-targeted TKIs. In order to treat iodine 131-refractory DTC, we sought to ascertain the safety and effectiveness of cediranib, a VEGFR-targeted TKI, with or without lenalidomide.