Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, representing 30-40% of cases. It is characterized by diffuse proliferation of large B-lymphoid cells and is clinically aggressive but potentially curable with immunochemotherapy. Gene expression profiling identifies two major molecular subtypes: germinal center B-cell (GCB) type with better prognosis and activated B-cell (ABC) type with inferior outcomes. MYC, BCL2, and BCL6 rearrangements define high-grade "double-hit" or "triple-hit" lymphomas with aggressive behavior. R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) remains standard frontline therapy, with novel approaches for relapsed disease.
name: Diffuse Large B-Cell Lymphoma
creation_date: '2026-01-26T02:55:13Z'
updated_date: '2026-03-13T12:00:00Z'
description: >-
Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma,
representing 30-40% of cases. It is characterized by diffuse proliferation of large
B-lymphoid cells and is clinically aggressive but potentially curable with
immunochemotherapy. Gene expression profiling identifies two major molecular subtypes:
germinal center B-cell (GCB) type with better prognosis and activated B-cell (ABC)
type with inferior outcomes. MYC, BCL2, and BCL6 rearrangements define high-grade
"double-hit" or "triple-hit" lymphomas with aggressive behavior. R-CHOP
(rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) remains standard
frontline therapy, with novel approaches for relapsed disease.
categories:
- Hematologic Malignancy
- B-cell Neoplasm
- Non-Hodgkin Lymphoma
- Aggressive Lymphoma
parents:
- B-cell non-Hodgkin lymphoma
epidemiology:
- name: Most common non-Hodgkin lymphoma
description: Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma.
evidence:
- reference: PMID:40753559
reference_title: "[Prognostic factors in elderly patients with diffuse large B-cell lymphoma and their treatment results.]."
supports: SUPPORT
snippet: "Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL)."
explanation: This abstract explicitly identifies DLBCL as the most common type of NHL.
has_subtypes:
- name: Germinal Center B-cell (GCB) Type
description: >-
DLBCL with gene expression profile resembling normal germinal center B cells.
Characterized by expression of GCB markers (CD10, BCL6, GCET1). Often harbors
BCL2 translocation and EZH2 mutations. Better prognosis than ABC type with
R-CHOP, with approximately 60-70% cure rates.
- name: Activated B-cell (ABC) Type
description: >-
DLBCL with gene expression profile resembling activated peripheral B cells.
Shows constitutive NF-kB activation, often through mutations in CD79A/B, CARD11,
MYD88, or deletions of A20. Inferior prognosis with standard R-CHOP. May benefit
from targeted agents inhibiting NF-kB pathway.
- name: High-Grade B-cell Lymphoma with MYC and BCL2 Rearrangements
description: >-
Double-hit lymphoma (DHL) with concurrent MYC and BCL2 translocations, or
triple-hit with MYC, BCL2, and BCL6 rearrangements. Highly aggressive with
poor outcomes to standard R-CHOP. Requires intensified therapy.
pathophysiology:
- name: Germinal Center B-cell Origin
description: >-
DLBCL arises from germinal center or post-germinal center B cells undergoing
somatic hypermutation and class switch recombination. These processes introduce
DNA double-strand breaks that can lead to oncogenic translocations. The cell
of origin determines molecular subtype and clinical behavior.
cell_types:
- preferred_term: centrocyte
term:
id: CL:0009111
label: centrocyte
- preferred_term: centroblast
term:
id: CL:0009112
label: centroblast
locations:
- preferred_term: lymph node
term:
id: UBERON:0000029
label: lymph node
downstream:
- target: BCL2 Overexpression and Apoptosis Resistance
description: BCL2 translocation blocks germinal center apoptosis
- target: MYC-Driven Proliferation
description: MYC rearrangement drives uncontrolled proliferation
- name: BCL2 Overexpression and Apoptosis Resistance
description: >-
BCL2 translocation t(14;18) occurs in approximately 30% of GCB-DLBCL, placing
BCL2 under immunoglobulin enhancer control. Resulting BCL2 overexpression
blocks the mitochondrial apoptosis pathway, allowing survival of cells that
would normally die in the germinal center.
biological_processes:
- preferred_term: apoptotic process
modifier: DECREASED
term:
id: GO:0006915
label: apoptotic process
downstream:
- target: Lymphoma Cell Accumulation
description: Apoptosis resistance enables lymphoma expansion
- name: MYC-Driven Proliferation
description: >-
MYC rearrangements occur in 10-15% of DLBCL, most commonly with IGH but also
with non-immunoglobulin partners. MYC overexpression drives cellular proliferation
and metabolism. When combined with BCL2 rearrangement (double-hit lymphoma),
creates highly aggressive disease.
biological_processes:
- preferred_term: cell population proliferation
modifier: INCREASED
term:
id: GO:0008283
label: cell population proliferation
downstream:
- target: Lymphoma Cell Accumulation
description: MYC drives rapid proliferation of lymphoma cells
- name: NF-kB Constitutive Activation
description: >-
ABC-DLBCL shows constitutive NF-kB activation through various mechanisms
including BCR signaling mutations (CD79A/B), CARD11 mutations, MYD88 L265P
mutation, or A20 deletion. NF-kB promotes survival and contributes to the
aggressive behavior of ABC subtype.
cell_types:
- preferred_term: B cell
term:
id: CL:0000236
label: B cell
biological_processes:
- preferred_term: signal transduction
modifier: INCREASED
term:
id: GO:0007165
label: signal transduction
downstream:
- target: Lymphoma Cell Accumulation
description: NF-kB signaling promotes lymphoma survival
- name: Lymphoma Cell Accumulation
description: >-
The combination of blocked apoptosis, enhanced proliferation, and constitutive
survival signaling leads to aggressive expansion of large B-cell lymphoma
involving lymph nodes and extranodal sites.
locations:
- preferred_term: lymph node
term:
id: UBERON:0000029
label: lymph node
cell_types:
- preferred_term: B cell
term:
id: CL:0000236
label: B cell
histopathology:
- name: Diffuse Large B-Cell Lymphoma
finding_term:
preferred_term: Diffuse Large B-Cell Lymphoma
term:
id: NCIT:C8851
label: Diffuse Large B-Cell Lymphoma
frequency: VERY_FREQUENT
description: Diffuse large B-cell lymphoma is the most common pathologic subtype.
evidence:
- reference: PMID:16613685
reference_title: "[Clinical features of 89 patients with primary non-Hodgkin's lymphoma of the tonsil]."
supports: SUPPORT
snippet: "Diffuse large B-cell lymphoma is the most common pathologic subtype."
explanation: Abstract notes DLBCL as the most common pathologic subtype.
phenotypes:
- category: Lymphatic
name: Lymphadenopathy
frequency: VERY_FREQUENT
description: >-
Rapidly enlarging lymphadenopathy is the most common presentation.
Nodal disease may be localized or widespread.
phenotype_term:
preferred_term: Lymphadenopathy
term:
id: HP:0002716
label: Lymphadenopathy
evidence:
- reference: PMID:29167021
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Patients most often present with a rapidly growing tumour mass in single or multiple, nodal or extranodal sites."
explanation: This comprehensive review confirms that rapidly growing nodal masses (lymphadenopathy) are the most common presentation of DLBCL.
- category: Constitutional
name: Night Sweats
frequency: FREQUENT
description: >-
B symptoms including drenching night sweats indicate active disease
and are incorporated into staging.
phenotype_term:
preferred_term: Night sweats
term:
id: HP:0030166
label: Night sweats
- category: Constitutional
name: Weight Loss
frequency: FREQUENT
description: >-
Unintentional weight loss greater than 10% body weight in 6 months
is a B symptom with prognostic significance.
phenotype_term:
preferred_term: Weight loss
term:
id: HP:0001824
label: Weight loss
- category: Constitutional
name: Fatigue
frequency: VERY_FREQUENT
description: >-
Fatigue from disease burden, cytokine release, and anemia.
phenotype_term:
preferred_term: Fatigue
term:
id: HP:0012378
label: Fatigue
- category: Abdominal
name: Splenomegaly
frequency: OCCASIONAL
description: >-
Spleen involvement occurs in some cases, particularly with
advanced stage disease.
phenotype_term:
preferred_term: Splenomegaly
term:
id: HP:0001744
label: Splenomegaly
- category: Hematologic
name: Anemia
frequency: FREQUENT
description: >-
Anemia may result from bone marrow infiltration, hemolysis,
or cytokine effects.
phenotype_term:
preferred_term: Anemia
term:
id: HP:0001903
label: Anemia
biochemical:
- name: Tissue Biopsy and Immunohistochemistry
notes: >-
Diagnosis requires tissue biopsy showing diffuse large B cells. IHC panel
includes CD20, CD3, CD10, BCL6, MUM1/IRF4, BCL2, MYC, and Ki-67.
Hans algorithm (CD10, BCL6, MUM1) classifies GCB vs non-GCB subtypes.
- name: FISH for Translocations
notes: >-
FISH testing for MYC, BCL2, and BCL6 rearrangements is essential to
identify high-grade double-hit or triple-hit lymphomas, which require
intensified treatment approaches.
genetic:
- name: BCL2 Translocation
association: GCB Subtype Marker
notes: >-
The t(14;18)(q32;q21) translocation occurs in 30% of GCB-DLBCL, placing
BCL2 under IGH enhancer control. When combined with MYC rearrangement,
defines double-hit lymphoma with aggressive behavior.
- name: MYC Rearrangement
association: Adverse Prognostic Marker
notes: >-
MYC translocations occur in 10-15% of DLBCL. MYC rearrangement with
BCL2 and/or BCL6 defines high-grade B-cell lymphoma (double/triple hit)
with poor prognosis requiring intensified therapy.
- name: MYD88 L265P Mutation
association: ABC Subtype Marker
notes: >-
MYD88 L265P is present in 30% of ABC-DLBCL and drives NF-kB activation
through TLR signaling. Associated with extranodal disease, particularly
CNS and testicular involvement.
- name: BCL6 Rearrangement
association: Lymphoma Driver
notes: >-
BCL6 translocations occur in 30% of DLBCL and may contribute to
oncogenesis. BCL6 is a transcriptional repressor essential for germinal
center function.
treatments:
- name: R-CHOP Immunochemotherapy
description: >-
Rituximab (anti-CD20), cyclophosphamide, doxorubicin, vincristine, and
prednisone is the standard frontline regimen. Six cycles cure approximately
60% of patients overall, with better outcomes in GCB subtype and localized
disease.
treatment_term:
preferred_term: chemotherapy
term:
id: MAXO:0000647
label: chemotherapy
therapeutic_agent:
- preferred_term: cyclophosphamide
term:
id: CHEBI:4027
label: cyclophosphamide
- preferred_term: doxorubicin
term:
id: CHEBI:28748
label: doxorubicin
- preferred_term: vincristine
term:
id: CHEBI:28445
label: vincristine
- preferred_term: prednisone
term:
id: CHEBI:8382
label: prednisone
evidence:
- reference: PMID:11807147
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "The rate of complete response was significantly higher in the group that received CHOP plus rituximab than in the group that received CHOP alone (76 percent vs. 63 percent, P=0.005)"
explanation: The landmark GELA trial established R-CHOP as the standard of care for DLBCL by demonstrating significantly improved complete response rates.
- name: Polatuzumab Vedotin plus R-CHP
description: >-
CD79b-directed antibody-drug conjugate combined with rituximab,
cyclophosphamide, doxorubicin, and prednisone. Approved as frontline
therapy providing improved outcomes compared to R-CHOP.
treatment_term:
preferred_term: pharmacotherapy
term:
id: MAXO:0000058
label: pharmacotherapy
therapeutic_agent:
- preferred_term: polatuzumab vedotin
term:
id: NCIT:C104153
label: Polatuzumab Vedotin
- name: Intensive Chemotherapy for Double-Hit Lymphoma
description: >-
High-grade lymphomas with MYC and BCL2 rearrangements require intensified
regimens such as DA-EPOCH-R or R-CODOX-M/R-IVAC rather than standard R-CHOP.
Outcomes remain inferior to non-double-hit DLBCL.
treatment_term:
preferred_term: chemotherapy
term:
id: MAXO:0000647
label: chemotherapy
- name: CAR-T Cell Therapy
description: >-
CD19-directed CAR-T cells (axicabtagene ciloleucel, lisocabtagene maraleucel,
tisagenlecleucel) are approved for relapsed/refractory DLBCL after two or
more prior lines. Achieves durable remissions in 30-40% of patients.
treatment_term:
preferred_term: immunotherapy
term:
id: MAXO:0001002
label: immunotherapy procedure
evidence:
- reference: PMID:33002134
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: "Patients treated with CAR T cell vs alternate therapies demonstrated a CR rate of 52% vs 22% (P < .001)"
explanation: Real-world comparison demonstrating CAR-T therapy achieves superior complete response rates compared to alternate therapies in relapsed/refractory DLBCL.
- name: Autologous Stem Cell Transplantation
description: >-
For chemotherapy-sensitive relapsed disease, high-dose therapy with ASCT
remains standard. CAR-T cells are alternative for transplant-eligible and
-ineligible patients with relapsed disease.
treatment_term:
preferred_term: hematopoietic stem cell transplantation
term:
id: MAXO:0000747
label: hematopoietic stem cell transplantation
- name: Radiation Therapy
description: >-
Consolidative radiation for localized (stage I-II) disease after
abbreviated chemotherapy improves local control. Involved-site
radiation therapy (ISRT) is standard approach.
treatment_term:
preferred_term: radiation therapy
term:
id: MAXO:0000014
label: radiation therapy
disease_term:
preferred_term: diffuse large B-cell lymphoma
term:
id: MONDO:0018905
label: diffuse large B-cell lymphoma
classifications:
icdo_morphology:
classification_value: Lymphoma
harrisons_chapter:
- classification_value: cancer
- classification_value: hematologic malignancy