Malignant neoplasms of testis are primary malignant neoplasm that affects the testis. More than 90% of testicular tumours are of germ cell origin.
Approximately 50% of germ cell tumours are seminomas, and the vast majority of the remainder are either pure forms of other subtypes or mixed germ cell tumours usually referred to as “non-seminomatous germ cell tumours” (NSGCTs). Seminomas and NSGCTs show differences in biological behaviour, and their precise classification has a profound effect on patient care.
Remaining malignancies of testis include mesenchymal, haematolymhoid tumours or sporadically other histological subtypes, however they are classified in the corresponding categories.