The Natural History of CLL

CD5‐negative chronic lymphocytic leukemia: Does this entity really exist?

“…1 Thus, already anticipating what should be the conclusion of these reflections, we submit that, in our view, there is currently not enough evidence to affirm that the so-called CD5-negative CLL exists as a "variant," "atypical," or a "subset" of CLL. In effect, although we do not take the position of asserting once and for all that CD5-negative CLL does not represent a variant of the classical CD5 + CLL, we believe there is room for the hypothesis that this entity could be another kind of B-cell lymphoma not biologically related to bona fide CLL and, therefore, belonging to another, yet unknown, category of diseases (Marti & Zenger, 2010;Sheikh et al, 2002). Unfortunately, the results of the comparison between classic CD5 + CLL and CD5-negative CLL with regard to clinical aspects, hematological parameters, disease stage, and survival are not sufficiently conclusive to allow us to state, at least preliminarily, that CD5-negative CLL is a distinct clinical entity (Demir et al, 2017).…”

“…With respect to the CD5 antigen, almost 100% of the participants considered it "required," although a small percentage (less than 5%) classified it only as "suggested" or "recommended," which would exclude our case from receiving the diagnosis of CLL (Rawstron et al, 2018. See also Marti & Zenger, 2010;Romano et al, 2015). Suppose now that our hypothetical patient undergoes additional multidisciplinary studies because his physician is not sure about the diagnosis.…”