Retroperitoneal malignancies several years after initial treatment of germ cell cancer of the testis.

Three patients (aged 56, 40, and 38 years, respectively) presenting with large retroperitoneal masses 10 to 18 years after prior orchiectomy for testicular neoplasms (seminoma and embryonal carcinoma) are presented. Despite aggressive chemotherapy in all three patients and surgical excision of the tumor in two, two of the men subsequently died 11 to 16 months after initial diagnosis of the retroperitoneal tumors, and one is living with the disease. Theoretic etiologic mechanisms for the development of late retroperitoneal tumors in these men are discussed, including (1) metastatic disease from a second primary tumor in the remaining testicle, (2) a primary extragonadal retroperitoneal tumor, and (3) delayed transformation of metastatic teratomatous retroperitoneal tumor from the original primary into malignant neoplasm.