Abstract: Objective： Testicular mixed germ cell tumor is mixed with embryonal carcinoma, choriocarcinoma, yolk sac tumor, teratoma, seminoma and other two or more components of the testicular tumor, the clinical is relatively rare and high degree of malignancy, this article will summarize its clinical features and optimize its treatment. Methods: A retrospective analysis of the clinical data of 22 patients with testicular tumor mixed germ cell in Peking University Third Hospital from May 1994 to November 2016 was conducted using a combination of statistical analysis and discussion of the relevant literature. Results: The mean age of the 22 patients was （30.8±10.4） years  and the rate of cryptorchidism was 13.6%. The maximum diameter of the tumor was （5.1±2.7 ） cm. The pathological results suggested that 12 cases (54.5%) contained two different germ cell tumor components, 7 cases (31.8%) contained 3 different tumor components, 2 cases (9.2%) contained 4 different tumor components, and 1 case (4.5%) contained 5 different tumor components. Tumor constituent analysis included yolk sac tumors(16 cases, 72.7%), mature teratoma (7 cases, 31.8%), immature teratoma (5 cases, 22.7%), embryonal carcinoma (17 cases, 77.3%) , choriocarcinoma (4 cases, 18.1%) and seminoma (6 cases, 27.3%). American Joint Committee of Cancer tumor staging indicated 19 cases of stage Ⅰ a tumor, 2 cases of stage Ⅱa tumor and 1 case of stage Ⅲa tumor. The mean values of human chorionic gonadotropin, alpha-fetoprotein and lactate dehydrogenase were 414.50 MIU/mL, 242.95 μg/L, 196.95 U/L (preoperative) and 17.20 MIU /mL, 90.20 μg/L, 183.70 U/L (postoperative within a year), and the comparison of the P values between the preoperative and the postoperative within a year were 0.079, 0.043 and 0.624.  Fourteen patients underwent retroperitoneal lymph nodes dissection. Most patients lived with long-term survival (94.4%) after operation. Conclusion: Comprehensive treatment of radical orchiectomy with retroperitoneal lymphadenectomy combined with necessary radiotherapy or chemotherapy might help to control the tumor and achieve long-term survival for most patients with testicular mixed germ cell tumor.

Key words: Testicular tumor, Pathologic diagnosis, Tumor markers, Retroperitoneal lymph node dissection