The histological examination showed an intratubular germ cell neoplasia (IGCNU), consisting of a mature teratoma and yolk sac tumor, with signs of pre-invasive lesion, such as presence of peri-neoplastic, placental alkaline phosphatase (PLAP) and CD117 positive seminiferous tubules, with basal nuclei and abundant clear cytoplasm (Figure 4). Here, ALPP is linked to teratoma.