97 Diffuse Large B-Cell Lymphoma and Related Diseases Flashcards
Histological description of DLBCL
Proliferation of sheets of large, transformed B lymphocytes (“centroblasts”) that replace and efface normal lymph node architecture
Diffuse large-cell lymphomas is an aggressive lymphoma, recognizing its potential to cause death within ___ months of diagnosis if left untreated.
3 months
Most common DLBCL subtype
DLBCL not otherwise specified (NOS)
Most common non-Hodgkin lymphoma (NHL) diagnosis globally
DLBCL
There is a slight ____________predominance, and incidence varies by ethnicity, with persons of European descent being more likely to develop the disease than people of African or Asian descent
Male
The median age of diagnosis
65 years
Gene translocation found in 40% of cases of DLBCL
B-cell lymphoma 6 gene (BCL6)
One-third of patients with DLBCL has this mutation and are usually associated with DLBCL arising from follicular lymphoma
t(14;18) involving the Ig heavy chain and BCL2
** coexistent mutations of p53 are often present
Approximately 10% of cases of DLBCL has this mutation and is associated with increased cell survival and a poorer clinical outcome
c-MYC
3 subtypes of DLBCL based on gene expression
- Germinal center B-cell-like (GCB)
- Activated B-cell like (ABC)
- Unclassifiable group
Mutated genes in ABC DLBCL
CD78B, PIM1, MYD88, and TNFA1P3
Other frequently mutated gene, such as CARD11, MLL2, and CREBP commonly exist in both ABC and GCB lymphomas.
Mutated genes in GCB DLBCL
MYC, BCL2, and EZXH2
Other frequently mutated gene, such as CARD11, MLL2, and CREBP commonly exist in both ABC and GCB lymphomas.
Which has inferior survival (ABC or GCB)
ABC lymphomas
Six molecular clusters of DLBCL
MCD
N1
A53
BN2
ST2
EZB
(EZB) was divided into two by the presence or absence of MYC expression
Poor prognosis: MCD, N1
Good prognosis: A53, BN2, EZB
Very Good prognosis: ST2
Molecular group identifier present in more than 90% of GCB type lymphomas
EZB
Molecular group identifier present in more than 90% of ABC type lymphomas
MCD
The A53 group was also ABC type in the majority of cases, yet this category had a good prognosis.
The typical presentation of DLBCL
Lymph node swelling
The classic “B symptoms” is present in approximately ___________of cases
One-third
The use of the B symptoms suffix is no longer used in the description of stage in the NHLs
Approximately _____of patients present with stage III or IV disease.
60%
The most common extranodal sites of involvement
Gastrointestinal tract or marrow
TRUE OR FALSE
Extranodal disease involvement is a marker of overall prognosis with the number of extranodal sites predicting both long-term survival and risk of CNS involvement at baseline or of CNS relapse.
TRUE
Extranodal disease involvement is a marker of overall prognosis with the number of extranodal sites predicting both long-term survival and risk of CNS involvement at baseline or of CNS relapse.
TRUE OR FALSE
Patients at high risk of CNS involvement should additionally undergo an examination of the cerebrospinal fluid by flow cytometry and cytology.
TRUE
Patients at high risk of CNS involvement should additionally undergo an examination of the cerebrospinal fluid by flow cytometry and cytology.
A marker of disease burden and is an important and universally available element of prognostic scoring systems
Elevation of the lactate dehydrogenase (LDH)
TRUE OR FALSE
Flow cytometry is sufficient alone to secure a diagnosis of DLBCL because the immunophenotypic features are unique to DLBCL and different from follicular lymphoma and Burkitt lymphoma.
FALSE
Flow cytometry is insufficient alone to secure a diagnosis of DLBCL because the immunophenotypic features are not unique to DLBCL and may be shared with follicular lymphoma and Burkitt lymphoma.
Immunophenotype of DLBCL
POSITIVE
pan B-cell antigens CD19, CD 20, CD 22, pax-5, and CD79a
pan-hematopoietic marker CD45
LESS COMMON
CD10 and CD5
CD5 coexpressing DLBCL, which must be differentiated from mantle cell lymphoma, may be associated with more clinically advanced presentations and a poorer outcome
CD10-positive disease must be differentiated from Burkitt lymphoma or follicular lymphoma based on histologic and molecular features.
Three cytologic patterns of DLBCL
Centroblastic, immunoblastic, and anaplastic
The diagnostic hallmark of most cases of DLBCL
Presence of sheets of large cells
Rearrangements in high-grade B-cell lymphoma (HGBL)
MYC and BCL2/and or BCL6
A full workup of DLBCL should typically include an IHC panel that allows the pathologist to determine the COO and to assess protein expression of BCL-2 and MYC
Fluorescence in situ hybridization (FISH) may determine the presence or absence of rearrangements of MYC.
Optimal imaging for staging of DLBCL
PET imaging with coregistered computerized tomography (CT) imaging
Magnetic resonance imaging (MRI) of the brain and spinal cord may be indicated in patients at the highest risk of CNS disease because PET imaging is useful but has reduced sensitivity in staging the CNS
How to differentiate viral infection syndromes should be differentiated from clonal disorders (large activated lymphocytes)
Absence of light-chain restriction by flow cytometry
Appropriate viral testing
The objective of the treatment of DLBCL
Cure
Clinical risk scores for DLBCL
International Prognostic Index (IPI)
NCCN-IPI
The risk of CNS involvement at baseline may be evaluated by use of the CNS-IPI.