we report a case of a patient with initially unresectable, widely metastatic, RET‐mutated medullary thyroid carcinoma treated on a single‐patient clinical protocol with neoadjuvant selpercatinib/LOXO‐292....Genomic molecular testing indicated a somatic RET deletion Y900_S904delinsP....A restaging CT following 4 cycles (~28 days each) of selpercatinib demonstrated marked interval improvement in multicompartmental nodal and visceral metastases in the neck, chest, and abdomen...