Contralateral testicular cancer in spite of TIN-negative double biopsies and interval cisplatin chemotherapy.

Background: Current models of tumorigenesis postulate that testicular germ cell cancer uniformly develops through a preinvasive lesion termed testicular intraepithelial neoplasia (TIN). An open testicular biopsy is a simple and highly sensitive method to diagnose TIN, and this procedure constitutes the basis for curative treatment of TIN. Patients with testis cancer carry a significantly increased risk of developing contralateral testicular tumors.