stage 0 testicular carcinoma in situ (...tes-TIH-kyuh-ler KAR-sih-NOH-muh in SY-too)
Abnormal cells are found in the tiny tubules where the sperm cells begin to develop. These abnormal cells may become cancer and spread into nearby normal tissue. All tumor marker levels are normal. Also called testicular intraepithelial neoplasia and testicular intratubular germ cell neoplasia.