[A Case of Metastatic Testicular Cancer after Kidney Transplantation in which Complete Remission was Achieved].

We report a case of testicular cancer after kidney transplantation in a 29-year-old man. Twenty-two years after the surgery, computed tomography (CT) showed a retroperitoneal mass 3 cm in diameter. Positron emission tomography (PET) -CT revealed high FDG uptake in both the right testis and retroperitoneal mass. Regarding serum tumor markers, α fetoprotein (AFP) was slightly elevated to 12.5 ng/ml. He underwent right radical orchiectomy, and pathological examination revealed pure seminoma. After surgery, the serum AFP level remained high (12. 9 ng/ml), and we initially considered this nonseminoma patient to have a good prognosis according to International Germ Cell Consensus Classification. During three cycles of a combination regimen including bleomycin, etoposide, and cisplatin (BEP), we performed adjustment of immunosuppressive therapy, treatment for Cytomegalovirus infection (valganciclovir hydrochloride), and that for other adverse events associated with systemic chemotherapy. The chemotherapy schedule was delayed, and bleomycin (third course, day 15) was skipped due to adverse effects. After 3 cycles of BEP, the retroperitoneal lymph node metastasis shrunk from 3.0 to 1.5 cm in diameter. In contrast to the good radiological response, the serum AFP level gradually increased during the treatment to 102.6 ng/ml. Therefore, we did not consider the AFP elevation to have derived from residual cancer, and decided to perform close follow-up. During the 3-year follow-up, AFP decreased to around 20 ng/ml, and PET-CT did not show any uptake in the retroperitoneal mass or other sites.