Extragonadal germ cell tumor in the retrovesical region associated with Klinefelter's syndrome: a case report and review of the literature.

We report a case of an extragonadal germ cell tumor from the retrovesical region associated with Klinefelter's syndrome. The patient presented with symptoms of macroscopic hematuria and micturition pain. An x-ray and digital examination were suspicious for prostatic carcinoma. However, needle biopsy of the tumor revealed embryonal cell carcinoma. Serum alpha-fetoprotein was 10,700 ng. per ml. Preoperatively, combined cytotoxic chemotherapy was administered and the antineoplastic effect was excellent. Serum alpha-fetoprotein rapidly returned to the normal range and the tumor volume decreased. Although the preoperative diagnosis was extragonadal germ cell tumor of the prostate, surgery revealed that the tumor originated from the retrovesical region. Orchiectomy and resection were performed. The resected tissue was mostly necrotic with a few viable cells of embryonal cell carcinoma, no metastatic lesions were detected in the lymph nodes and no masses were noted in the testes. Postoperatively, the patient was treated with cytotoxic chemotherapy. His condition has remained good with no clinical evidence of recurrence of the disease.