<prompt> Most common testicular tumourSeminomaTeratomaSeoli cell tumourChorio ca  <response>: Seminoma is the most common germ cell tumor of the testis or, more rarely, the mediastinum or other extra- gonadal locations. It is a malignant neoplasm and is one of the most treatable and curable cancers, with a survival rate above 95 if discovered in early stages. 