The group of cancers under the general term Lymphoma is quite broad. The distinctions between types of lymphoma are based on the different characteristics of the cancerous cells. Over the years, different classification systems have been used to differentiate lymphomas:

• Rappaport: Used until the 1970s, Rappaport was based on how the cells look in the microscope alone
• Kiel: Used mainly in Europe, the Kiel system, is based on microscopic and immunologic (what types of proteins are produced by the cell) criteria, it was updated in 1992.
• National Cancer Institute's Working Formulation (IWF): Ontroduced in 1982, the IWF divided lymphomas into low-grade, intermediate-grade and high-grade, with subgroups based on cell type and presentation

Revised European-American Classification of Lymphoid Neoplasms (REAL): Introduced in 1994, REAL describes the different types of lymphomas as entities, with each type classified according to cell origin, based on morphologic, immunologic and genetic criteria.

Historically, uniform treatment of patients with lymphoma has been hampered by the lack of uniformity in these classification systems.

The following comparison of the Working formulation and the Rappaport system is shown in case older records use some of this terminology:

Working formulation	Rappaport classification
Low-grade A.small lymphocytic, consistent with chronic lymphocytic leukemia (SL) B.follicular, predominantly small cleaved cell (FSC) C.follicular, mixed small cleaved and large cell (FM)	diffuse lymphocytic, well -differentiated (DLWD) nodular lymphocytic poorly differentiated (NLPD) nodular mixed, lymphocytic and histiocytic (NM)
Intermediate-grade D. follicular, predominantly large cell (FL) E. diffuse, small cleaved cell (DSC) F. diffuse mixed, small and large cell (DM) G. diffuse, large cell cleaved or noncleaved cell (DL)	nodular histiocytic(NH) diffuse lymphocytic poorly differentiated (DLDP) diffuse mixed, lymphocytic and histiocytic (DM) diffuse histiocytic (DH)
High-grade H. immunoblastic, large cell (IBL) I. lymphoblastic, convoluted or nonconvoluted cell (LL) J. small noncleaved cell, Burkitt's or non-Burkitt's (SNC)	diffuse histiocytic (DH) diffuse lymphoblastic (DL) diffuse undifferentiated, Burkitt's or non-Burkitt's (DU)

As the understanding of lymphoma has improved and as the histopathologic diagnosis (the study of the cancerous cells themselves) of lymphoma has become more sophisticated, a number of new pathologic entities were described. In addition, the understanding and treatment of many of the previously described pathologic subtypes changed. As a result, the Working Formulation had become outdated and less useful to clinicians and pathologists. Thus, European and American pathologists have proposed a new classification, the Revised European American Lymphoma (REAL) Classification.

The REAL Classification

B-cell neoplasms
I. Precursor B-cell neoplasm: precursor B-lymphoblastic leukemia/lymphoma
II. Peripheral B-cell neoplasms

A. B-cell chronic lymphocytic leukemia/prolymphocytic leukemia/small lymphocytic lymphoma
B. Lymphoplasmacytoid lymphoma/immunocytoma
C. Mantle cell lymphoma
D. Follicle center cell lymphoma, follicular

1. Provisional cytologic grades:

I small cell,
II mixed small and large cell,
III large cell

2. Provisional subtype: diffuse, predominantly small cell type

E. Marginal zone B-cell lymphoma

1. Extranodal (MALT-type +/- monocytoid B cells)
2. Provisional subtype: nodal (+/- monocytoid B cells)

F. Provisional entity: splenic marginal zone lymphoma (+/- villous lymphocytes)
G. Hairy cell leukemia
H. Plasmacytoma/plasma cell myeloma
I. Diffuse large B-cell lymphoma

1. Subtype: primary mediastinal (thymic) B-cell lymphoma

J. Burkitt's lymphoma
K. Provisional entity: high-grade B-cell lymphoma, Burkitt-like

T-cell and putative NK-cell neoplasms
I. Precursor T-cell neoplasm: precursor T-lymphoblastic lymphoma/leukemia
II. Peripheral T-cell and NK-cell neoplasms

A. T-cell chronic lymphocytic leukemia / prolymphocytic leukemia
B. Large granular lymphocyte leukemia

1. T-cell type
2. NK-cell type

C. Mycosis fungoides/Sezary's syndrome
D. Peripheral T-cell lymphomas, unspecified

1. Provisional cytologic categories: medium-sized cell, mixed medium and large cell, large cell, lymphoepithelioid cell
2. Provisional subtype: hepatosplenic gamma/delta T-cell lymphoma
3. Provisional subtype: subcutaneous panniculitic T-cell lymphoma

E. Angioimmunoblastic T-cell lymphoma
F. Angiocentric lymphoma
G. Intestinal T-cell lymphoma (+/- enteropathy associated)
H. Adult T-cell lymphoma/leukemia
I. Anaplastic large cell lymphoma

1. CD30+ -cell type
2. T-cell type
3. Null-cell types

J. Provisional entity: anaplastic large cell lymphoma, Hodgkin's-like

Hodgkin's Disease (now known to be a B-cell neoplasm)
I. Lymphocyte predominance
II. Nodular sclerosis
III. Mixed cellularity
IV. Lymphocyte depletion
V. Provisional entity: lymphocyte-rich classical Hodgkin's disease

Back to Lymphomas - Current Classifications

 

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For more information on Adult Non-Hodgkin's lymphoma, please see the following pages:

Adult Non-Hodgkin's Lymphoma: Diagnosis
Adult Non-Hodgkin's Lymphoma: Aggressive Lymphomas
Adult Non-Hodgkin's Lymphoma: Indolent Lymphomas
Adult Non-Hodgkin's Lymphoma: Follicular Lymphomas
Adult Non-Hodgkin's Lymphoma: Large Cell Lymphomas
Adult Non-Hodgkin's Lymphoma: Treatment
Adult Non-Hodgkin's Lymphoma: Resources

For more information on Childhood Non-Hodgkin's Lymphoma:

Childhood Non-Hodgkin's Lymphoma: Introduction
Childhood Non-Hodgkin's Lymphoma: Diagnosis
Childhood Non-Hodgkin's Lymphoma: Treatment
Childhood Lymphoma: Resources

For more information on Hodgkin's Disease:

Adult Hodgkin's Lymphoma Information Pages
Childhood Hodgkin's Information Pages