Secondary CD5+ diffuse large B-cell lymphoma not associated with transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (Richter syndrome)

Am J Clin Pathol. 2009 Mar;131(3):339-46. doi: 10.1309/AJCP58FETFGLCKKW.

Abstract

Few cases of secondary CD5+ diffuse large B-cell lymphoma (DLBCL) that are not Richter syndrome have been reported previously. We report 9 cases of non-Richter syndrome secondary CD5+ DLBCL. Among 529 cases of DLBCL, 38 (7.2%) were CD5+ DLBCL, including 9 of secondary CD5+ DLBCL. Five cases gained CD5 expression during the clinical course of DLBCL (group 1). Three cases showed transformation from CD5- low-grade B-cell lymphoma to CD5+ DLBCL (group 2). The remaining case showed coexistence of CD5+ DLBCL and CD5+ follicular lymphoma. The clonal relationships of CD5- and CD5+ tumors were confirmed in all 4 available cases. Cases of secondary CD5+ DLBCL that were not Richter syndrome were classifiable into 3 groups. Groups 1 and 2 showed the gain of CD5 during the clinical course or transformation of the tumors, suggesting that CD5 expression is closely associated with the progression of B-cell lymphoma.

MeSH terms

  • CD5 Antigens / biosynthesis*
  • Cell Transformation, Neoplastic
  • Flow Cytometry
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology*
  • Lymphoma, Large B-Cell, Diffuse / classification*
  • Lymphoma, Large B-Cell, Diffuse / metabolism*
  • Lymphoma, Large B-Cell, Diffuse / pathology*
  • Polymerase Chain Reaction

Substances

  • CD5 Antigens