Page 268 - Essential Haematology

254 / Chapter 20 Non-Hodgkin lymphoma

Non - Hodgkin l ymphomas site of involvement (e.g. skin, central nervous
system (CNS), intestine, spleen, mediastinal) as

These are a large group of clonal lymphoid tumours,

important in disease classification.
about 85% of B cell and 15% of T or NK (natural

killer) cell origin (Table 20.1 ). Their clinical pres-
entation and natural history are more variable than Classifi cation

in Hodgkin lymphoma. They are characterized
by an irregular pattern of spread and a signifi cant Th e lymphomas are classifi ed within a group of
proportion of patients develop extranodal disease. mature B - cell and T - cell neoplasms , which also
Their frequency has increased markedly over the last includes some chronic leukaemias and myeloma

50 years and with an incidence of approximately 17 which are described in Chapters 18 and 21 , respec-
in 100 000 they now represent the fi fth most tively (Table 20.1 ). In this chapter we consider the

common malignancy in some developed countries more common lymphoma subtypes within this
(see Fig 11.1 ) . The aetiology of the majority of cases classifi cation.

of non - Hodgkin lymphomas (NHL) is unknown
although infectious agents are an important cause Cell of o rigin
in particular subtypes (Table 20.2 ). There are also

considerable geographical variation (Table 20.2 ). Th e normal B - cell development stages are illustrated

The World Health Organization (WHO) classifi ca- in Fig. 9.10 . B - cell lymphomas tend to mimic
tion also recognizes age (paediatric or elderly) and normal B cells at diff erent stages of development

Table 20.1 The World Health Organization ( WHO ) classifi cation of mature B - cell and T - cell
neoplasms (modifi ed), which includes the non - Hodgkin lymphomas. B - cell disorders comprise
85% of cases. T cell and NK cell together comprise 15% of cases. A few very rare subtypes have
been omitted.

Mature B - cell neoplasms Mature T - cell and NK - cell neoplasms
Chronic lymphocytic leukaemia/small lymphocytic T - cell prolymphocytic leukaemia
lymphoma T - cell large granular lymphocytic leukaemia
B - cell prolymphocytic leukaemia Adult T - cell lymphoma/leukaemia
Splenic marginal zone lymphoma Extranodal NK/T - cell lymphoma, nasal type
Hairy cell leukaemia Enteropathy - associated T - cell lymphoma
Lymphoplasmacytic lymphoma – Waldenstr ö m Mycosis fungoides
macroglobulinaemia S é zary syndrome
Heavy chain diseases Peripheral T - cell lymphoma
Plasma cell myeloma Angioimmunoblastic T - cell lymphoma
Plasmacytoma Anaplastic large cell lymphoma, ALK positive
Extranodal marginal zone lymphoma of mucosa -
associated lymphoid tissue (MALT lymphoma)
Follicular lymphoma
Mantle cell lymphoma
Diffuse large B - cell lymphoma
Burkitt lymphoma

ALK, anaplastic lymphoma kinase, the gene on chromosome 2 which is overexpressed; NK, natural killer.