Diagnosis of Contralateral Testicular Intraepithelial Neoplasia (TIN) in Patients with Testicular Germ Cell Cancer: Systematic Two-Site Biopsies Are More Sensitive Than a Single Random Biopsy

We confirmed the prevalence of contralateral TIN to be about 5%. TIN is significantly associated with poor spermatogenesis and with testicular atrophy. The diagnostic extra yield imparted by double biopsies is 18%. Discordant results regarding TIN are predominantly encountered in normal-sized testicles. The new standard in diagnosing TIN is two-site biopsy.