Ancient retroperitoneal schwannoma imitating seminoma recurrence: A case report.

A 28-year-old male with bilateral testicular seminoma underwent bilateral orchiectomy and radiation therapy of the retroperitoneum. After 17 years, he had a retroperitoneal tumor detected, which was removed 7 years later at age 52 because of its progressive enlargement. Due to its partially cystic and partially solid structure, the radiologic findings could not exclude the possibility of regressively altered seminoma metastasis.