WOW! That is amazing!
I didn't have any symptoms either, it was my PMC Dr that found something that bothered him on my normal urine tests, and sent me to the Urologist, who was puzzeled as well, and thus said, "Well lets just do a kidney ultrasound and send you on your way" wrong....ultrasound showed something, but they couldn't diagnose it from that, so I had a CT the same day --- and there it was! So you just never know do you.
So, you guys gave each other an amazing gift of life -- who knows where Marc would be without your gift, and what he thus averted! Cheers to both of you