Operated undecended testicle showed tumor cells . enlarged paraaortic lymph node in ct. but tumor markers normal. high alt(67). is it still seminoma?

In situ?: The diagnosis of seminoma is made on examination of tissue by the pathologist; tumor markers and imaging are ancillary studies. An undescended testis often has premalignant cells lining the tubules; these are not yet cancer and if gone will not be troublesome. If you were told there was indeed an actual seminoma, that's a different story & you may require followup such as biopsy of the node.