Who would I speak with to obtain second opinion about a diagnosis of multiple myeloma?

I would definitely seek a second Hospital for a different opinion. Good luck to you

Yes, go to GW Hospital, I goes to both of them

I agree. Go to another hospital to get a second opinion. Especially for someting that important.

I would say go to an different hospital to get an second diagnosis. You may want to check with George Washington hospital center the specialist there are great.