1: Mature B-Cell Neoplasms

Current WHO standards group a large group of B Cell neoplasms, including many non-Hodgkin's lymphomas, some leukaemias and myeloma under this heading. Their unifying feature is the resemblance of tumour cells to a type of mature B Cell. This resemblance is the basis of subclassification into the well known diffuse large B Cell, follicular, mantle cell and marginal zone lymphomas.
A summary of the epidemiology is given below:

Type Age Gender Geography Incidence
DLBCL 60 Slightly more men N/A Most common lymphoma
Follicular 50-60 70% women High in West
Less in Developing
20% of all lymphoma
Burkitt Children & Young Adults
Mantle Cell
Marginal Zone
Myeloma 65-70 More men African descent 3rd most common lymphoma
CLL 60 2:1 Higher in West Most common adult leukaemia

A summary of the microscopic appearances is presented below:

Type Architecture Cell Size Cytoplasm Nucleus
DLBCL Sheets of cells, no nodularity Intermediate to large Eosinophilic Vesicular
Follicular Closely packed follicles
Diffuse in high grade cases
Centrocytes: Small
Centroblasts: Intermediate
Cleaved nucleus
Vesicular, nucleoli
Burkitt Diffuse, "Starry Sky" Intermediate
Mantle Cell Follicular Small Minimal Cleaved nucleus
Marginal Zone
Myeloma Diffuse Normal Perinuclear clearing Eccentric
CLL Diffuse Small Scant Slightly irregular

A summary of immunohistochemical appearances:

  • CD19, CD20 and CD79a are present in almost all B cell lymphomas
  • The remaining CD markers are used for distinguishing between certain types.
    • CD5 and CD23 are present in mature B cells (CLL)
  • marker
Type CD79a CD20 CD19 CD5 CD10 CD15 CD23 CD30 CD34 Cyclin D1 Ig BCL2 BCL6
DLBCL + + +/-
Follicular + + + - + - - - - - + + +
Mantle Cell + + + + - - - - - + +
Marginal Zone
CLL + + + + - - + - - - + - -

A summary of common chromosomal changes:

Type Translocations Other findings
Follicular BCL2/IGH
Burkitt cMYC/IGH
Mantle Cell Cyclin D1/IGH
Marginal Zone MALT/BCL10
t(14;18), t(11;18), t(1;14)
CLL Rare Nil

Mature B Cell Neoplasms