Quick question about CLL/SLL: naive B cell proliferation

[AxiomaticTruth]

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So in Pathoma Dr. Sattar says that typically in chronic leukemias, there is a proliferation in mature cells, while in acute it's usually immature progenitor cells. However in CLL/SLL there's a proliferation of immature B cells. Is that the only exception to the rule? Or should I forget about that rule completely?

 

[Entadus]

So in Pathoma Dr. Sattar says that typically in chronic leukemias, there is a proliferation in mature cells, while in acute it's usually immature progenitor cells. However in CLL/SLL there's a proliferation of immature B cells. Is that the only exception to the rule? Or should I forget about that rule completely?

They're mature in the sense that they are beyond the Lymphoblastic stage of differentiation. They're B-cells not blasts so that explains the "chronic" classification. When they say "immature B-cells" that is just to distinguish CLL/SLL from the plasma cell dyscrasias like Multiple Myeloma.

The basic outline I have in my head right now (Suuuuper abridged) is as follows:
Hematopoietic stem cell -> Lymphoid progenitor stem cell -> (B)-Lymphoblast -> Immature/Naive B-cell -> Mature B-cell -> Plasma cell
Obviously I'm skipping a ton of steps, for example the whole process going from Naive B-cell to Mature B-cell within the follicles of lymphoid tissue.

Seeing the relative position of the bolded cell type, they are clearly more differentiated than lymphoblast (so it's not an acute leukemia) but the cells are also not as mature as some of the other lymphomas and plasma cell dyscrasias.

Hopefully this makes sense (it's been a while since I studied heme-onc)

 

[AxiomaticTruth]

Ah no you make perfect sense. It makes more sense to think of chronic as "more mature cells" than acute leukemias, but since there's multiple steps along maturation of cells, any one of them could be the proliferating stage. Thanks!