Chronic B cell malignancies and bone marrow microenvironment

Chronic B-lymphoid malignancies depend upon supportive interactions within specific microenvironments. Follicular lymphoma (FL), chronic lymphocytic leukaemia (CLL) and multiple myeloma (MM) cells accumulate in the bone marrow (BM) where they receive survival or growth signals from by-stander cells. However, they deeply differ in their interaction with the microenvironment. We propose a model where FL and CLL recreate in the BM the microenvironment most suitable to their growth by 'importing' the normal cells that usually nurse them in secondary lymphoid organs. In contrast, MM takes advantage of the actual BM microenvironment by 'instructing' it through an abnormal activation state.