ESPE Abstracts

Background: Boys with PWS often have unilateral or bilateral cryptorchidism. Prospective studies on the treatment of cryptorchidism in boys with PWS are lacking and there is no treatment consensus among pediatricians and urologists.

Objective and hypotheses: We hypothesized that hCG treatment would lead to a scrotal position of the testes in infants with PWS and cryptorchidism. We therefore evaluated the effects of hCG treatment on testis position. Additionally, in those who underwent orchidopexy, testis histology was studied.

Method: Sixteen infants with PWS, median (IQR) age 1.6 (1.2–1.8) years, were treated with hCG. After a positive stimulation test, hCG treatment was initiated (i.m. injection, 250–500 IE depending on age, twice a week for 6 weeks). hCG treatment was defined successful in case of bilateral stable scrotal position. Indications for operation were patent processus vaginalis, non-scrotal position or non-stable scrotal position of the testis.

Results: Thirty-one of the 32 testes had a non-stable scrotal position. All infants had a positive response to hCG stimulation, with a median (IQR) testosterone increase of 5.9 (3.5–9.2) nmol/l. After hCG treatment, 83% of testes had descended to a lower position, with seven to a stable scrotal position, not requiring orchidopexy. Twenty-four testes underwent orchidopexy. Of 15 obtained biopsies, two had more than 60% of germ cells, three between 30–60%, seven <30% and three showed Sertoli cell-only syndrome. In infants who underwent orchidopexy, a younger age, higher Inhibin B levels and higher testosterone increase after hCG stimulation were associated with a higher number of germ cells. Testis position before hCG treatment was not associated with the number of germ cells.

Conclusion: Our study demonstrates that HCG treatment in infants with PWS results in a lower testis position. Nevertheless, 13 infants required an additional orchidopexy. A younger age at orchidopexy is associated with a better histological outcome.