A case of testicular cancer with retroperitoneal lymph node metastasis of teratoma with somatic-type malignancy 18 years after initial treatment.

In testicular cancer, late relapse of teratoma with somatic-type malignancy is rare and associated with a poor survival. A case of retroperitoneal lymph node metastasis of teratoma with somatic-type malignancy 18 years after initial treatment for testicular cancer is reported. A 46-year-old man had a 15-mm-sized mass in the para-aortic region 18 years after initial treatment for testicular cancer, without elevated serum alfa-fetoprotein or human chorionic gonadotropin levels. Laparoscopic retroperitoneal lymph node dissection was performed. The pathological findings showed teratoma with somatic-type malignancy, and the findings of primary testicular cancer reported a yolk sac tumor, not teratoma. Late relapse of teratoma with somatic-type malignancy was resected by laparoscopic retroperitoneal lymph node dissection. Therefore, long-term follow-up should be considered if patients with small retroperitoneal masses did not undergo retroperitoneal lymph node dissection, and early detection and surgical resection for relapse might be effective.