Is angioimmunoblastic t-cell lymphoma still treatable if in the marrow, anemia, low platelets, swelling?

Yes: Chemotherapy goes throughout the body and can be used to treat widespread lymphoma.

T cell lymphoma: It is treatable but need careful supervision under the oncologist as chemo can be detrimental with low blood counts but sometimes that is the only way marrow can be cleared of lymphoma so lot of thinking needs to be done in selecting appropriate chemo for such patients.