Lymphoma & related disorders

Mature B cell neoplasms

Large B cell lymphomas-special subtypes

LBCL with IRF4

Editorial Board Member: Genevieve M. Crane, M.D., Ph.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Jayalakshmi Balakrishna, M.D.

Last author update: 27 March 2019
Last staff update: 1 June 2023 (update in progress)

Copyright: 2019-2023,, Inc.

PubMed Search: Large B cell lymphoma with IRF4 rearrangement OR lymphoma of Waldeyer ring

Jayalakshmi Balakrishna, M.D.
Page views in 2022: 1,564
Page views in 2023 to date: 804
Cite this page: Balakrishna J. LBCL with IRF4. website. Accessed June 8th, 2023.
Definition / general
  • Uncommon subtype of large B cell lymphoma characterized by strong expression of IRF4 / MUM1
  • Commonly associated with IRF4 gene rearrangement
Essential features
  • Children and young adults
  • Lymph nodes of head and neck or Waldeyer ring are affected
  • Diffuse, diffuse and follicular or follicular pattern
  • Medium to large cells
  • Germinal center B cell phenotype with diffuse IRF4 / MUM1 expression
  • Most cases show IRF4 rearrangement
  • Lymphoma of Waldeyer ring
ICD coding
  • ICD-O: 9698/3 - follicular lymphoma, grade 3
  • ICD-10: C83.3 - diffuse large B cell lymphoma
  • Rare subtype accounting for 0.05% of diffuse large B cell lymphomas
  • Primarily affects children and young adults
  • Equal gender incidence (Blood 2011;118:139)
Clinical features
  • Isolated lymph node enlargement
  • Tonsillar enlargement
  • Biopsy of the involved lymph node / tissue with immunophenotyping and confirmation using FISH analysis for IRF4 rearrangement
  • Strong, diffuse positivity for IRF4 / MUM1 in neoplastic cells
  • Young age of the patient, head and lymph node / Waldeyer ring location
Prognostic factors
  • Favorable response to treatment with immunochemotherapy
Case reports
  • Responds well to chemoimmunotherapy with or without radiation
Gross description
  • Involved lymph node / tonsil is enlarged
  • Firm, fleshy homogenous mass
Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Jayalakshmi Balakrishna, M.D.

Diffuse pattern

Expansile follicles

Diffuse effacement
with medium
sized cells

Medium sized atypical lymphoid cells

Round to irregular nuclear contours and conspicuous nucleoli

Follicular pattern






Positive stains
Negative stains
Flow cytometry description
  • Low side light scatter and moderate forward light scatter
  • Pan B cell markers and CD10 positive
  • Surface immunoglobulin light chain positive with monoclonal pattern
Molecular / cytogenetics description
Molecular / cytogenetics images

Contributed by Itziar Salaverria, Ph.D.

FISH break apart probe for IRF4

Sample pathology report
  • Lymph node, left cervical, excision:
    • Large B cell lymphoma with IRF4 rearrangement; see synoptic report
Differential diagnosis
Board review style question #1

An 8 year old boy has tonsillar enlargement. Which stain is most likely positive in the neoplastic cells?

  1. CD1a
  2. CD3
  3. MUM1
  4. TdT
Board review style answer #1
Board review style question #2
Which is the common partner gene of IRF4 in large B cell lymphoma with IRF4 rearrangement?

  1. BCL2
  2. c-Myc
  3. IgH
  4. IgK
Board review style answer #2
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