Aberrant Bcl6 protein expression in mantle cell lymphoma

Am J Surg Pathol. 2004 Aug;28(8):1051-6. doi: 10.1097/01.pas.0000128671.92609.af.


Mantle cell lymphoma is routinely considered as a Bcl6-negative B-cell lymphoma carrying the translocation t(11;14). Here we describe a series of five Bcl6-positive mantle cell lymphoma cases, including three classic and two blastoid variants. The proliferative index of these cases, measured with the Ki-67 antibody, was slightly higher than in Bcl6-negative mantle cell lymphoma cases (32.2 vs. 23.7%) Bcl6 expression was associated with translocations involving 3q27 in four of the five cases and an extra copy of the BCL6 gene in the fifth. A mutational study of the major mutational cluster in the BCL6 gene revealed no increased mutation rate, except in one case. One of the three cases displayed a high mutational index in the IgVH gene, suggesting exposure to a germinal center microenvironment. Chromosomal alterations involving 3q27 seem to be responsible for this increased Bcl6 expression, which needs to be considered when Bcl6 is used in lymphoma diagnosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis
  • Chromosomes, Human, Pair 3*
  • DNA, Neoplasm / analysis
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Female
  • Humans
  • Immunoglobulin Variable Region / genetics
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Lymphoma, Mantle-Cell / genetics*
  • Lymphoma, Mantle-Cell / metabolism*
  • Lymphoma, Mantle-Cell / pathology
  • Male
  • Middle Aged
  • Polymerase Chain Reaction
  • Proto-Oncogene Proteins c-bcl-6
  • Sequence Analysis, DNA
  • Translocation, Genetic*


  • BCL6 protein, human
  • Biomarkers, Tumor
  • DNA, Neoplasm
  • DNA-Binding Proteins
  • Immunoglobulin Variable Region
  • Proto-Oncogene Proteins c-bcl-6