I'm 23, male, had ct scan show a lesion of a few millimeters on bladder. no other symptoms. what are the odds this is cancer? what else could this be?

Need cystoscopy ...: I assumed the reason for having CT was blood in urine or bacterial urinary tract infection. So, thus far, you need a direct look at the whole interior of the bladder to make sure this tiny lesion of few mm is a tumor or a false image (this is possible). For a 23-y-o man, a malignant lesion is not highm but still possible; I have seen a low-grade malignant tumor in a man as young as 18 yrs old.