Hello,
Regarding Mayo Rochester, I was there June 19th, 2019 and was given my SMZL diagnosis. ( I have had other cancer diagnosis and surgeries there as well)

You can look a the Mayo Hematology list of Doctors on their website and there are a number of B-cell lymphoma as their interest or specialty. My experience with Mayo is that they are very specialized and use a team approach and consultation within their specialties. Since 2019, I have seen a couple different Hematologists and nurse practitioners and have been comfortable with all of them. So based on your diagnosis, I expect you would be routed to the appropriate doctor (s).
It is my opinion that depending on your timeline, diagnosis, test results, they may want to see more or newer testing to confirm your diagnosis and or treatment path.

In my opinion, you have made the best possible choice to seek care at Mayo. It's not only the doctors, their entire system of scheduling, testing, treatment, communication, and compassion has amazed me.

The Mayo facilities are huge, but there is much information and instructions available on line. Once you arrive there are many help desks or volunteers and are very helpful.

Do you have a long way to travel?
Well I hope all goes well. Let us know if you have other questions.