HEMA 2 LEC - Mature B Cell Lymphomas Part 1 Flashcards
Type of lymphoma
• Derived from various stages of B cell differentiation
MATURE B CELL LYMPHOMAS
Type of lymphoma
All produce monoclonal light chain Ig, clonal Ig gene rearrangements, or both
MATURE B CELL LYMPHOMAS
Type of lymphoma
Most common subtypes: follicular lymphoma and B cell lymphoma
MATURE B CELL LYMPHOMAS
• Accumulation of small lymphoid cells in PB, BM, lymphoid organs
Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma
type of lymphocytic leukemia or lymphoma presents mostly in PB and BM
CLL
type of lymphocytic leukemia or lymphoma presents mostly in LN
SLL
Morphology
• Soccer-ball : small lymphoid cells with coarse chromatin, absent or subtle nucleoli, scant cytoplasm
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CLL
Morphology
Prolymphocytes (up to 55% of cells)
CLL
Morphology
Lymphoid cells with cleaved nuclei
CLL
FAB CLassification of CLL
>90% small mature lymphocytes,
Typical CLL
- Smudge cells (disintegrated lymphoid cells) – unique feature
- BM: nodular, diffuse, interstitial infiltrates of small lymphoid cells
CLL
- Effacement of normal nodal architecture by a diffuse proliferation of small, round lymphoid cells (Pathognomonic)
- Pseudofollicles/growth or proliferation centers
SLL
Used to distinguish CLL/SLL from mantle cell lymphoma: (5)
CD23, LEF1, absence of FMC7, cyclin D1, SOX11
What condition
• Monoclonal B-cell lymphocytosis:
• Asymptomatic at diagnosis, 1st indication: lymphocytosis
CLL/SLL
Two Divisions of CLL:
indolent, median survival: 24 years
Mutated IVGH (Ig heavy chain)
Two Divisions of CLL:
aggressive, median survival: 8 years
Unmutated IVGH
5% of patients of CLL/SLL patients develop _____ high-grade diffuse large B cell lymphoma with survival of
Richter syndrome
> 55% of circulating lymphoid cells have prolymphocyte morphology
prolymphocytic leukemia
Pathognomonic cell of B cell PLL:
prolymphocyte of medium size, round nucleus, distinct punched out nucleolus
LN involvement more common in what type of PLL (B or T cell)
T cell
how to distinguish B CELL PLL from CLL/SLL
To distinguish from CLL/SLL: cell size (2x normal) and prominent central nucleolus (PUNCHED OUT)
- BM: interstitial and/or nodular proliferation of prolymphocytes
- Infiltrated white and red splenic pulp
B CELL PLL
- BM: small to medium size neoplastic cells with round or irregular nuclei, resembling Sezary cells
- Cytoplasmic blebbing
T CELL PLL
high incidence of mutation in TP53 what subclass of PLL
B cell PLL
Treatment for PLL
monoclonal Ab against CD52
Definition
Small B lymphocytes with abundant cytoplasm and fine/hairy cytoplasmic projections
Hairy Cell Leukemia
Cell of origin of HCL
peripheral b cell of post-germinal center stage (memory B cell)
Found in BM and red pulp of spleen, RARE LN involvement
HCL
Inc in reticulin fibers
HCL
Expression of CD11c, CD25, CD103, TRAP
HCL
most specific markers; differentiates HCL from splenic marginal zone lymphoma
CD123, Annexin A1
In MIDDLE aged
HCL
Signs of this disease are splenomegaly and pancytopenia
HCL
Definition
• Medium-sized lymphoid cell with irregular nuclear outlines derived from follicular mantle zone
Mantle Cell Lymphoma
• Main site of presentation of MCL
LN
replacement of normal nodal architecture with a diffuse proliferation of monotonous, medium-sized lymphoid cells with irregular nuclear outlines
MCL
irregular nuclear outlines
MCL
PB involvement may mimic PLL
MCL
this cytogenetic abnormality is a defining feature of mantle cell lymphoma
t(11;14)
proto-oncogene involved in the regulation of G1 to S phase progression
Cyclin D1 (BCL1)
constitutively expressed through its translocation to the immunoglobulin heavy chain gene, t(11;14)
Cyclin D1 (BCL1)
Origin of Follicular lymphoma
Germinal center B cells
Morphology
• Numerous closely spaced follicles
Follicular Lymphoma
Morphology
Neoplastic proliferation may extend into the perinodal adipose tissue
Follicular Lymphoma
- Mantle zone and polarization are not present
* Neoplastic follicles with medium-sized lymphoid cells with angular or indented nuclei
Follicular Lymphoma
• Cytologically similar to centrocytes, with a variable admixture of large lymphoid cells
Follicular Lymphoma
• Prognostic significance: relative proportion of medium-sized and large lymphoid cells
Follicular Lymphoma
grade of FL
rare scattered large lymphocytes
grade 1-2
grade of FL
numerous centroblasts
Grade 3
Neoplastic cells express BCL-2 protein
Follicular lymphoma
responsible for the decreased sensitivity to apoptosis in follicular lymphoma
allows the accumulation of neoplastic lymphocytes
BCL-2 protein
The expression of BCL-2 by follicular lymphoma cells is due to the _______, which places the BCL2 gene under a promoter of the immu noglobulin heavy chain gene
t(14;18)(q32;q21)
This cytogenetic abnormality is present in 95% of follicular lymphoma
t(14;18)(q32;q21)
3 subtypes of Marginal Zone Lymphoma of MALT
1) nodal, 2) extranodal, 3) splenic
heterogenous neoplastic proliferation, small and medium lymphocytes, plasma cells, scattered large lymphoid cells
Extranodal Marginal Zone Lymphoma of MALT
Associated with autoimmune conditions (e.g., Sjögren syndrome, Hashimoto thyroiditis) or previous infections (Helicobacter pylori gastritis or hepatitis C)
Extranodal Marginal Zone Lymphoma of MALT
Characteristic feature: lymphoepithelial lesions
Extranodal Marginal Zone Lymphoma of MALT
helpful feature in diagnosing marginal zone lymphoma when there is a significant residual reactive component
CD43 antigen
• 30% of cases show a translocation involving apoptosis-inhibitor gene API2 and the MLT gene, the t(11;18)(q21;q21).
Extranodal Marginal Zone Lymphoma of MALT
API2 and the MLT gene, the t(11;18)(q21;q21)
What lymphoma
Extranodal Marginal Zone Lymphoma of MALT
most common site of Extranodal Marginal Zone Lymphoma of MALT
GIT