ABSTRACT
Immunoblastic variant 85 Anaplastic variant 86 Molecular subgroups 87 Immunohistochemistry 87 Genetics 87 T-cell/histiocyte-rich large B-cell lymphoma 88 Epstein-Barr virus-positive diffuse large B-cell
lymphoma of the elderly 89 Primary mediastinal (thymic) large B-cell lymphoma 89 Immunohistochemistry 90 Genetics 90 Differential diagnosis 90 ALK-positive large B-cell lymphoma 90 Other large B-cell lymphomas 91 Primary large B-cell lymphoma of the central
nervous system 91 Primary cutaneous DLBCL, leg type 92 DLBCL associated with chronic inflammation92 Lymphomatoid granulomatosis 92 Intravascular large B-cell lymphoma 93 Plasmablastic lymphoma 93 Large B-cell lymphoma arising in human
herpesvirus-8-associated multicentric Castleman disease 93
Primary effusion lymphoma 93 Burkitt lymphoma 93 Types of Burkitt lymphoma 95 Morphology 95 Immunohistochemistry 96 Genetics 96 Differential diagnosis 96 B-cell lymphoma, unclassifiable, with features
intermediate between DLBCL and Burkitt lymphoma96 Genetics 96 B-cell lymphoma, unclassifiable, with features
intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma 96
References 97
Mature B-cells are characterized by the synthesis, expression and sometimes secretion of immunoglobulin molecules. The almost infinite diversity of these molecules is achieved by rearrangement (shuffling) of the constant, joining, diversity and variable regions of the immunoglobulin genes. Further diversity occurs in follicle centres by the process of somatic mutation of the variable region genes. Thus, at the genetic level, mature B-cells are characterized by rearranged immunoglobulin genes. Follicle centre and post-follicle centre cells have mutated variable region genes.
