Revised 14 March 2013
The diagnosis of malignant lymphoma requires the presence of malignant lymphocytes in a biopsy of lymph node or extra-lymphatic tissue. An excisional lymph node biopsy is essential for complete diagnostic assessment. If a whole lymph node is not obtainable, sufficient incised tissue from an extra-lymphatic site can be diagnostic but is less desirable. Fine needle aspiration biopsy (see Appendix I: Biopsy Procedures) is not sufficient for the initial diagnosis of malignant lymphoma.
The following histologic sub-classification of the malignant lymphomas is an adaptation of the WHO classification (Swerdlow, Tumours of Hematopoietic and Lymphoid Tissues, World Health Organization Classification of Tumours, IARC Press, 2008) and is based on the light microscopic interpretation complemented by special stains, immunophenotyping, cytogenetics and other information as available. The specific lymphomas are divided into three major groups for treatment planning.
Table 3.1
A clinically oriented classification of the lymphomas based on similar natural histories, modes of presentation and responses to treatment using the terminology of the REAL classification scheme:
Grade | B-cell | T-cell |
Indolent | Small lymphocytic* Lymphoplasmacytic** Follicular, grade 1, 2 or 3 A Primary cutaneous follicle center cell Marginal zone | Mycoses fungoides Cutaneous anaplastic large cell |
Aggressive | Follicular, grade 3 B Mantle cell Diffuse large cell+ Primary mediastinal large B cell Primary central nervous system large B cell B cell, unclassifiable, with features intermediate between DLBCL and Burkitt B cell, unclassifiable, with features intermediate between DLBCL and Hodgkin lymphoma | Peripheral T cell, unspecified Angioimmunoblastic T cell(AIL) Nasal T/NK cell Subcutaneous panniculitic T cell Enteropathy associated T cell Hepatosplenic T cell Anaplastic large cell (CD30 positive) including null cell |
Special | Burkitt | Lymphoblastic |
* Small lymphocytic lymphoma is biologically similar to chronic lymphocytic leukemia and is treated the same as CLL
** Includes Waldenstrom’s Macroglobulinemia
*** Mucosa-associated lymphoid tissue
+ Includes T-cell rich B-cell, immunoblastic and intravascular variants of diffuse large B-cell lymphoma