Levels of serum miRNA, including miR-371a-3p, miR-373-3p and miR-367-3p, were measured using the ampTSmiR (amplification targeted serum miRNA) test in 82 patients, including 39 in cohort 1 and 43 in cohort 2, who were treated with orchiectomy, chemotherapy and post-chemotherapy retroperitoneal lymph node dissection. miRNA levels were compared to clinical characteristics and serum tumor markers, and correlated with the presence of viable germ cell tumor vs fibrosis/necrosis and teratoma.