Discussion
In this patient case, onco-TESE was the last chance to preserve fertility, because he had been diagnosed with azoospermia. It has been previously reported that testicular tumor is associated with decreased spermatogenic ability, and the sperm concentration in testicular tumor patients was about 1/3 that of general males and the total sperm count was about 1/6.14 Most spermatogenesis was affected after the chemotherapy, and there was the report that spermatogenesis recovered in 75% of patients 18 months later, but it was clear to lose of fertility after orchiectomy because he was congenital single testicular patient.15 According to literature statistics, the frequency of diagnosed congenital single testis during surgery for cryptorchidism in Europe and the United States is 4%.16 Assisted reproductive technology has advanced in recent years, allowing infertile patients to achieve fertilization by using cryopreserved sperm.17,18 Papers from several groups of investigators6,19-21 have been reported that Onco-TESE is possible in patients with azoospermia and testicular cancer followed by the use of assisted reproduction to birth of healthy baby by cryopreserved sperm, but in each case there were no reports of congenital single testis with testicular cancer patient. This case shows that Onco-TESE can be done in patients with congenital single testis such as TDS syndrome. It is important to operate as many people as possible with Onco-TESE.