Dieckmann KP et al. (2007) Spermatogenesis in the contralateral testis of patients with testicular germ cell cancer: histological evaluation of testicular biopsies and a comparison with healthy males. BJU Int 99: 1079–1085

A large German study has shown that spermatogenesis is markedly reduced in the contralateral testis of patients with testicular germ cell tumors (GCTs). This finding supports the hypothesis of testicular dysgenesis syndrome, a cluster of characteristics including cryptorchidism, hypospadias, hypospermatogenesis and GCT that share pathogenic developmental pathways.

The investigators prospectively enrolled 2,318 GCT patients from 114 centers. To test the assumption that spermatogenesis is homogeneously distributed, patients underwent a two-site biopsy of the contralateral testicle, and spermatogenesis was histologically classified. Comparable biopsies obtained at autopsy from 1,388 presumably healthy men in a previous study were used as controls.

The histology results showed that spermatogenesis was significantly poorer in the GCT patients compared with controls. Hypospermatogenesis was significantly associated with cryptorchidism, infertility, testicular atrophy and advanced clinical stage; in addition, spermatogenesis was not always homogeneous throughout the testis, with 5.4% of cases showing discordant findings on double biopsy. As this phenomenon was predominantly seen in patients with infertility or atrophic testes, the authors recommend that multiple biopsies are performed during the histological evaluation of male infertility.

While these results are consistent with testicular dysgenesis syndrome, another possible interpretation is that the endocrine activity of GCT leads to impaired sperm production. The authors speculate that a combination of these two mechanisms probably contributes to the reduced spermatogenesis seen in the contralateral testes of patients with GCT.