ATM and granular cell tumor: Here, we present the first case of a 60-year Caucasian male with a heavily pretreated, cisplatin-refractory extragonadal non-seminomatous GCT (choriocarcinoma) treated with pembrolizumab and olaparib based on high programmed death-ligand 1 expression (tumor proportion score 50% and a combined positive score 55%) high tumor mutational burden, borderline genomic loss of heterozygosity, and a heterozygous variant of uncertain significance in the DNA repair gene ATM, as confirmed by next-generation sequencing (NGS) analysis.