A) I would say follow up on the possible blood cancer. The screening process is designed to protect you as the donor, so it sounds like there is a possible big health concern there.

B) Consider 2nd, 3rd, 4th opinions. I was declined by my local hospital and was devastated, but then realized that that didn't necessarily have to be the final word. Hospitals want healthy donors, so do some research and see if there is another place that feels like a good match for you and check it out. I was able to donate at another hospital and had very few issues and received excellent care. But seriously, follow up on the blood cancer concern...