All of the following are characteristic features of Diffuse Large B-Cell Lymphoma (DLBCL) EXCEPT:
A. Presents as an aggressive lymphoma with rapid clinical progression
B. t(8;14) translocation involving MYC and immunoglobulin heavy chain
C. Arises de novo or as transformation from indolent lymphoma
D. CD20 and CD79a positivity on immunophenotyping
Explanation
Characteristic Features of DLBCL
Key Point
DLBCL is the most common type of non-Hodgkin lymphoma (30–40% of all NHL). Understanding its defining features is essential for NEET PG.
Immunophenotypic Profile
Table
Feature
DLBCL
Comment
CD20
Positive
B-cell marker; target for rituximab
CD79a
Positive
B-cell associated antigen
CD5
Negative
Helps exclude CLL/SLL
CD23
Usually negative
Helps exclude CLL/SLL
Ki-67
High (>40%)
High proliferation index
High-YieldNEET PG
DLBCL is CD20+ CD79a+ CD5− CD23−, which distinguishes it from CLL/SLL (which are CD5+ CD23+).
Cytogenetic Abnormalities
Warning
The t(8;14) translocation is characteristic of Burkitt lymphoma, NOT DLBCL. This translocation juxtaposes the MYC oncogene on chromosome 8 with the immunoglobulin heavy chain (IgH) locus on chromosome 14, leading to MYC overexpression.
Clinical Pearl
While DLBCL may have complex karyotypes and occasional MYC rearrangements (in "double-hit" lymphomas), t(8;14) as a primary defining feature is specific to Burkitt lymphoma.
Clinical Presentation & Course
Aggressive behavior: Rapid growth, B symptoms common
De novo or secondary: Can arise directly or transform from indolent lymphomas (e.g., follicular lymphoma → DLBCL)
Age: Median 64 years; can occur at any age
Sites: Nodal and extranodal involvement
Mnemonic
DLBCL = Diffuse, Large, B-cell (CD20+), Complex karyotype, Large cells. NOT t(8;14).
Why t(8;14) is Wrong for DLBCL
The t(8;14) translocation is the hallmark of Burkitt lymphoma, a separate entity characterized by:
Small to medium-sized cells (not large)
"Starry sky" appearance on histology
Extremely high proliferation rate (Ki-67 ~100%)
Endemic, sporadic, and immunodeficiency-associated forms
While "double-hit" or "triple-hit" DLBCL may carry MYC + BCL2/BCL6 rearrangements, t(8;14) alone is not a defining feature of DLBCL.
High-YieldNEET PG
On NEET PG, if asked about t(8;14), think Burkitt lymphoma first. If asked about DLBCL cytogenetics, think complex karyotype or BCL2/BCL6 translocations in germinal center subtype.
Robbins 10e Ch 13
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