We reported a 19-year-old male patient with pretreated metastatic mixed TGCT harboring 5 variations in the BRCA2, MSH6 and PMS2 genes detected using plasma-based circulating tumor DNA (ctDNA). He obtained a durable clinical benefit from single-agent Camrelizumab (a PD-1 inhibitor), with the progression-free survival (PFS) of over 19 months and overall survival (OS) of over 6 years.