Definition
Seminoma is the most common pure germ cell tumor (GCT) of the testis, accounting for up to 50% of cases.
Among mixed GCTs, seminoma is also commonly present, in which the combination of teratoma, seminoma, yolk sac tumor, and embryonal carcinoma represent about one third of mixed cases. Overall, 60% of germ cell neoplasms have seminoma either as pure tumor or a component of a mixed tumor.
Testicular GCT is the most prevalent solid malignancy affecting young male adults (most commonly from age 35 to 45 years). However, reports of children (8 y) and elderly (73 y) also appear in the literature.