Based on what has come out today, it appears the specific lymphoma he has is “Nodal Marginal-Zone B-Cell Lymphoma”.
This has not been explicitly stated, but his oncologist stated he had “marginal zone lymphoma”, and it was spotted in a lymph node in his neck.
Do you have any additional comments on this particular kind of lymphoma?
To be cold-hearted about it, the question is "Will the disease will seriously affect Fred Thompson's ability to function as President between now and January 20 2017?" and the answer is probably not.
To be cynical about things, one wonders how the RATs will approach this, as well as Giuliani's inactive prostate cancer and McInsane's inactive melanoma, given Elizabeth Edwards' recent diagnosis of metastatic breast cancer, a much more serious situation (though she isn't running for office). Considering the types of "get well" wishes they have sent to Dick Cheney and Tony Snow, I expect they will continue to disgrace themselves.