• By the end of this session you should be able to:– Discuss the basis of the classification of
lymphomas– Know the different stages of B lymphocyte– List common genetic abnormalities in
lymphomas– Classify Hodgkin lymphoma and the difference
between the subtypes
Lymphoma• Classification WHO
– Lymphoid, Myeloid, Histiocytic
• Definitions:– Precursor, mature, stage of differentiation, naïve, peripheral,
small cell, large cell– CD’s
• Common types: Follicular lymphoma, Diffuse large B cell lymphoma
• Age: – Non Hodgkin: 6th- 7th decade– Hodgkin: 3rd decade
The Journey of the B cells
• Bone marrow- Blast- VDJ gene rearrangement- mature naïve Ig positive cells- IgM, IgD, CD5+
• Antigen- transformation- proliferation- mature B cell IgM
• Germinal center maturation, Somatic mutation.• IgG, IgA plasma cells and memory cells.• Plasma cells- bone marrow
The Journey of the B cells• Bone marrow- Blast- VDJ gene rearrangement- mature
naïve Ig positive cells- IgM, IgD– CD20, CD19,CD10, TdT, CD5+/-
• Antigen- transformation- proliferation- mature B cell IgM– CD20, CD10, Bcl-2
• Germinal center maturation, Somatic mutation.– CD20
• IgG, IgA plasma cells and memory cells.– Loose all the B cell markers CD138+
• Plasma cells- bone marrow
Genetics
• Follicular lymphoma t(14;18)– Bcl-2 over expression
• Mantle cell lymphoma: t(11;14)– CyclinD1 over expression
• Burkitt lymphoma: t(8;14)– C-myc over expression
Classification
• Based on:– Morphology– Immunophenotyping– Clinical presentation– Molecular/cytogenetic findings