Contralateral testicular relapse after prophylactic radiation in a patient with primary testicular diffuse large B‐cell lymphoma

Prophylactic radiation to the contralateral uninvolved testicle has become a standard practice in the treatment of primary testicular lymphoma. While it is generally felt to be very effective, its failure rate is unknown. We describe a patient with primary testicular diffuse large B‐cell lymphoma, who developed recurrent disease in the contralateral testicle despite receiving prophylactic testicular radiation, central nervous system prophylaxis, and anthracycline‐based chemo‐immunotherapy. Review of the literature shows that the testicular failure rate after prophylactic radiation may be unexpectedly high at 10% or more. We put forward hypotheses on testicular relapse and discuss potential alternative preventive strategies.