Diagnostic Approach and Management of Unilateral Testicular Atrophy

Initial Evaluation and Risk Stratification

The European Association of Urology recommends measuring testicular volume using an orchidometer, with atrophy defined as testicular volume <12 ml or a size difference >2 ml (or >20%) compared to the contralateral testis 1, 2
Men with a history of cryptorchidism have a 3.6-7.4 times higher risk of testicular cancer, and therefore require testicular biopsy to exclude intratubular germ cell neoplasia in situ (GCNIS) 3, 4
Infertile men with testicular atrophy (<12 ml volume) should undergo testicular biopsy, as they belong to a higher-risk group for GCNIS 1, 2

The European Association of Urology strongly recommends orchidectomy for adult men with unilateral testicular atrophy and normal hormonal function/spermatogenesis in the contralateral testis 1, 2, 4
For men with unilateral atrophic testis and impaired contralateral function, orchiopexy may be offered if technically feasible, with mandatory biopsy for GCNIS detection 1, 2, 3
The European Association of Urology recommends against using hormonal treatment (GnRH or hCG) for cryptorchidism in postpubertal men, as evidence shows poor success rates 1, 2, 3

All men with testicular atrophy should perform regular testicular self-examinations and receive counseling about increased cancer risk, even after surgical intervention 1, 3, 4
Men with unilateral atrophy typically have near-normal paternity rates if the contralateral testis is healthy, while men with bilateral atrophy have significantly reduced paternity rates of 35-53% 3, 4
Orchiopexy performed before puberty reduces testicular cancer risk 2-6 fold compared to postpubertal surgery, but risk remains elevated compared to men without cryptorchidism 3, 4