Retroperitoneal schwannoma mimicking lymph node metastasis of seminoma.

We report a case of retroperitoneal schwannoma mimicking lymph node metastasis. A 32-year-old man presented with an intrascrotal mass, and underwent radical orchiectomy. Histological examination revealed a typical seminoma of the testis. Systemic work-up for staging demonstrated a retroperitoneal mass, which was located in the supra-hilar inter-aortocaval region. Under the diagnosis of retroperitoneal metastasis of the seminoma, he underwent three courses of cisplatin, vinblastine, and bleomycin (PVB) therapy. Persistence of the tumor after the chemotherapy led to retroperitoneal lymphadenectomy, histological examination then revealing a benign schwannoma. The location of the tumor and its unresponsiveness to chemotherapy might be useful indicators for differentiating lymph node metastasis of seminoma from primary tumors of other origin.