What is the difference between Hodgkin and non-Hodgkin lymphoma?

Hodgkin lymphoma is defined histologically by the presence of Reed-Sternberg cells within a reactive background and tends to spread in an orderly, contiguous fashion. Non-Hodgkin lymphoma is a large and heterogeneous group of lymphoid neoplasms of varied cell type and clinical behavior that lack Reed-Sternberg cells.

How are lymphomas classified?

The WHO classification groups lymphoid neoplasms by cell lineage (B-cell, T-cell, or NK-cell) and by the stage of normal lymphocyte development they resemble, combining morphology, immunophenotype, genetic features, and clinical presentation into defined disease entities.

Lymphoma

Lymphoma is a malignant neoplasm of lymphocytes that typically presents as a solid tumor of lymphoid tissue, most often in lymph nodes but also in extranodal sites. Lymphomas are broadly divided into Hodgkin lymphoma and the diverse non-Hodgkin lymphomas, and are further classified by the cell lineage (B-cell, T-cell, or NK-cell) and the stage of normal lymphocyte development they resemble. They form a large and heterogeneous family of lymphoid neoplasms.

Definition

A lymphoma is a malignant neoplasm arising from lymphocytes, classified by lineage and differentiation stage and divided principally into Hodgkin lymphoma and the non-Hodgkin lymphomas.

Scope

The entry covers the lymphoid origin of lymphoma, the Hodgkin versus non-Hodgkin distinction, the lineage- and maturation-based framework of the WHO classification of lymphoid neoplasms, and the principles of anatomic staging of nodal disease. It treats lymphoma as a category of malignant neoplasm; leukemias and the general biology of malignancy are addressed in related entries.

Core questions

What cell of origin defines lymphoma?
How do Hodgkin and non-Hodgkin lymphomas differ?
On what basis does the WHO scheme classify lymphoid neoplasms?
What distinguishes indolent from aggressive lymphomas?
How is the anatomic extent of lymphoma described?

Key concepts

Lymphoid (lymphocyte) origin
Hodgkin versus non-Hodgkin lymphoma
B-cell, T-cell, and NK-cell lineage
Reed-Sternberg cell (Hodgkin lymphoma)
Indolent versus aggressive behavior
Immunophenotyping and molecular classification
Nodal and extranodal disease

Key theories

Maturation- and lineage-based classification of lymphoid neoplasms: The WHO classification organizes lymphomas by cell lineage (B, T, or NK) and by correspondence to a recognizable stage of normal lymphocyte development, integrating morphology, immunophenotype, genetics, and clinical features into defined disease entities.

Mechanisms

Lymphomas arise from lymphocytes that have undergone malignant transformation, often during the genetic remodeling that accompanies normal lymphocyte development — for example the immunoglobulin and T-cell receptor gene rearrangements that can produce oncogenic translocations. The resulting neoplasms tend to recapitulate a stage of normal B-, T-, or NK-cell maturation, which is the basis for their classification. Hodgkin lymphoma is defined by the presence of characteristic Reed-Sternberg cells within a reactive cellular background, whereas non-Hodgkin lymphomas comprise many entities of differing cell type and clinical tempo. Diagnosis integrates morphology with immunophenotype and molecular genetics, and clinical behavior ranges from indolent to highly aggressive. Anatomic extent is described by staging of involved nodal regions and extranodal sites.

Clinical relevance

Lymphomas are a major category of hematologic malignancy, and their precise classification frames how the diverse entities are described and studied. The integration of morphology, immunophenotype, and genetics into defined entities, together with anatomic staging, provides a shared vocabulary for these neoplasms. This entry is a reference orientation to the category and does not provide diagnostic criteria or treatment guidance for any individual.

Epidemiology

Lymphomas constitute a substantial share of hematologic cancers, with non-Hodgkin lymphoma considerably more common than Hodgkin lymphoma. Incidence varies by subtype, age, geography, and immune status, and certain infections and immunodeficiency states are associated with particular lymphoma types.

Evidence & guidelines

The classification of lymphoid neoplasms is maintained by the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, with the 2016 revision a widely cited reference framework; anatomic extent is described by stage. General principles are consolidated in references such as Robbins & Cotran Pathologic Basis of Disease. These sources describe classification and staging conventions rather than prescriptive clinical protocols.

History

Thomas Hodgkin's nineteenth-century description of enlargement of lymphatic glands gave its name to Hodgkin lymphoma, and the characteristic giant cells were later detailed by Carl Sternberg and Dorothy Reed. The twentieth century saw a succession of classification schemes for the non-Hodgkin lymphomas, culminating in the lineage- and maturation-based WHO framework that integrates morphology, immunophenotype, and genetics; the 2016 revision is a widely used iteration of that consensus.

Key figures

Thomas Hodgkin
Dorothy Reed
Carl Sternberg
Elaine Jaffe
Steven Swerdlow

Seminal works

swerdlow-2016

Frequently asked questions

What is the difference between Hodgkin and non-Hodgkin lymphoma?: Hodgkin lymphoma is defined histologically by the presence of Reed-Sternberg cells within a reactive background and tends to spread in an orderly, contiguous fashion. Non-Hodgkin lymphoma is a large and heterogeneous group of lymphoid neoplasms of varied cell type and clinical behavior that lack Reed-Sternberg cells.
How are lymphomas classified?: The WHO classification groups lymphoid neoplasms by cell lineage (B-cell, T-cell, or NK-cell) and by the stage of normal lymphocyte development they resemble, combining morphology, immunophenotype, genetic features, and clinical presentation into defined disease entities.