Pathogenic mutations of <i>MSH2</i> and <i>BRCA2</i> were found in the DNA extracted from her tumor, and subsequent genetic analysis confirmed the germline pathogenic variant of <i>MSH2.</i> As such, this case was genetically diagnosed as Lynch syndrome.<h4>Conclusion</h4>We report metastatic urothelial cancer in a patient with Lynch syndrome who demonstrated a radiological complete response to pembrolizumab therapy. This evidence concerns the gene MSH2 and Lynch syndrome.