Lymphoma and plasma cell neoplasms
B cell lymphoma subtypes
Unclassifiable, features between Burkitt and diffuse large B cell lymphoma

Author: Nikhil Sangle, M.D. (see Authors page)

Revised: 3 April 2017, last major update February 2011

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PubMed Search: unclassifiable b cell lymphoma

Cite this page: Unclassifiable between Burkitt and DLBCL. PathologyOutlines.com website. http://pathologyoutlines.com/topic/lymphomabunclassburkitt.html. Accessed April 24th, 2017.
Definition / General
  • New entity (2008) with features intermediate between Burkitt lymphoma and diffuse large B cell lymphoma
  • Includes cases with:
    1. Proliferation index > 90% and "starry sky" appearance, but marked variation in cytomorphology not acceptable for Burkitt lymphoma
    2. Uniform medium sized cells but not the typical immunophenotype of Burkitt lymphoma, such as strong BLC2 staining or proliferation index < 90%, or
    3. Transformations of prior low grade B cell lymphoma with MYC rearrangement (J Hematop 2009;2:89)
Terminology
  • New entity in 2008 WHO classification
  • Complete name is: B cell lymphoma, unclassifiable, with features intermediate between diffuse large B cell lymphoma and Burkitt lymphoma
  • Also called "double hit" lymphoma
  • Includes the prior entity of Burkitt-like or atypical Burkitt lymphoma
Pathophysiology
  • Includes Burkitt-like transformation of follicular lymphoma
  • Aggressive nature likely reflects their simultaneous expression of both pro-proliferative (MYC) and antiapoptotic (BCL2) oncoproteins
Clinical Features
Micro Description
  • Cellular pleomorphism and heterogeneity intermediate between Burkitt lymphoma and diffuse large B cell lymphoma
Flow Cytometry Description
Molecular / Cytogenetics Description
  • Often "double hit" lymphomas, with MYC rearrangements with non-IGH genes, with a complex karyotype possibly involving BCL2 and, less frequently, BCL6 rearrangements (Blood 2011;117:2319)