A case report of mediastinal seminoma arising after renal transplantation.

Recipients of organ transplantation on immunosuppressive medications are at increased risk for developing de novo malignancies, including skin cancer, Kaposi's sarcoma, in situ carcinomas of the uterine cervix, anogenital cancers, renal cell carcinoma, and post-transplant lymphoproliferative disorders (PTLD). However, there are few case reports of germ cell tumors after organ transplantation. There are some case reports of testicular seminoma, but not mediastinal seminoma. This case report is the first description of a mediastinal seminoma that developed de novo 28 months after renal transplantation and that was initially diagnosed as PTLD. To improve outcomes of organ transplant recipients, it is important to report rare cases of malignancies arising while on immunosuppressive medications. When we detect mediastinal tumor arising after organ transplantation while on immunosuppressive therapy, diseases other than PTLD should be considered in the differential diagnosis.