A short report on current fertility preservation strategies for boys.

Background: Advances in cancer treatment have led to improved long-term survival after childhood cancer, but often at a price of impaired future fertility. Fertility preservation (FP) in male children and early adolescents poses unique challenges as efficacy is unproven. Objectives: To describe characteristics of testicular tissue cryopreservation (TTCP) specimens taken from paediatric and adolescent patients, stratified by age, and prior chemotherapy, if any, and to demonstrate evidence for germ cells. Materials and methods: Retrospective review of gonadal biopsies and clinical records of patients consented into the Royal Children's Hospital FP programme between 1987 and 2015. Tissue was sliced into blocks, with one section sent for histopathology prior to cryopreservation. In boys >= 12 years where spermatogenesis could be expected, a portion of tissue was disaggregated completely to look for mature sperm and if found, additional tissue was dissected and the resulting suspension frozen. Results: Testicular tissue cryopreservation specimens in 44 males (0.3-16.8 years) provided an average of 7.8 slices per patient. All the specimens were taken at the same time as another necessary surgical procedure, under one general anaesthesic. There was only one complication of scrotal wound dehiscence. Seven of the forty-four (15.9%) patients had chemotherapy prior to testicular biopsy, while the rest were chemotherapy naive. Five of these were prepubertal, and two were pubertal patients. Eleven subjects had tissue dissected with mature sperm found in eight. Of these eight patients where sperm were found, all were pubertal with testicular size of more than 10 mL and showing histological evidence of spermatogenesis. No histologic specimen demonstrated any malignant cells. Conclusions: Testicular tissue cryopreservation can be performed in young patients without delay, preferably prior to cancer treatment. As testicular tissue contains germ cells from which haploid spermatozoa are ultimately derived, future technologies may allow their utilization for fertility in humans. This may be the only hope for biological offspring in some patients undergoing fertility compromising treatment. Retrieval of mature sperm from some pubertal patients, however, offers realistic hope to these patients of future fertility.