Testicular seminoma originating in an undescended testis in a renal allograft recipient.

Immunosuppressed transplant recipients are at significantly increased risk for developing neoplasms than are nonimmunosuppressed individuals. However, only six cases of pure testicular seminoma following renal transplantation have been reported in the English literature. This case report represents the first description of a seminoma arising in an undescended testis post-transplantation. We propose that it may be prudent to remove atrophic undescended testes when lifelong immunosuppressive therapy is anticipated, because accelerated tumor growth can occur.