B-Cell Prolymphocytic Leukemia
A rare mature B-cell leukemia (~1% of cases) composed of medium sized lymphoid cells (2x size of normal lymphocyte), which typically has splenic and bone marrow involvement.
- >55% (often >90%) of lymphoid cells are prolymphocytes (prominent central nucleolus containing a denser chromatin rim)
- Exclusion of leukemic phase of mantle cell lymphoma
- Present with rapidly increasing WBC count (typically >100,000/uL
- May be difficult to differentiate from
- CLL/SLL with increased prolymphocytes
- Mantle cell lymphoma (MCL)
- MCL will have evidence of t(11;14) or cyclin D1/SOX-11 expression
- Splenic marginal zone lymphoma (SMZL)
- SMZL is compose of small lymphocytes with expand the white pulp of the spleen in the characteristic marginal zone pattern
- B-PLL expands white pulp nodules and involves the red pulp by medium to large cells with abundant cytoplasm with a central nucleolus
- Non-specific immunophenotype
Immunophenotype
|
CD19
CD20
CD79a
FMC7
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Positive
|
|
CD5
|
20-30%
|
|
CD23
|
10-20%
|
|
ZAP-70
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50% – does not correlated with IgHV mutation status
|
|
CD38
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50%
|
References
Swerdlow SH, Campo E, Harris, NL, Jaffe ES, Pileri SA, Stein H, Thiele J (Eds): WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th edition). IARC: Lyon 2017