world cancer report - iarc

T
Fig. 5.101 Nuclear magnetic resonance imaging
scan of the brain of an HIV-infected patient showing
a large lymphoma (T) in the basal ganglia.
Fig. 5.102 Follicular non-Hodgkin lymphoma.
Detection
The most common presentation of non-
Hodgkin lymphoma is painless swelling of
the lymph nodes in the neck, armpit or
groin. This may be associated with so
called “B symptoms” of unexplained fever,
night sweats and weight loss. Other related
symptoms include fatigue, malaise,
pruritus, or those related to organ involvement
(e.g. indigestion caused by gastric
lymphoma). Extranodal involvement is
common. Diagnosis is dependent on
obtaining a tissue biopsy, usually by excision
of an enlarged node. Pathological
review is crucial to identify the type of
lymphoma.
Staging practice commonly involves full
blood count, biochemical screen including
tests of liver function and renal function,
chest X-ray, CT scan of neck, chest,
abdomen and pelvis, and bone marrow
biopsy. In some instances, lumbar puncture
may be required to assess central
nervous system involvement, which can
have important therapeutic implications.
Hodgkin disease usually originates in
lymph nodes (often in the neck), and only
rarely spreads outside primary lymphoid
tissues. Diagnosis requires a tissue biopsy,
ideally a whole lymph node. Many of
the staging techniques employed are the
same as for non-Hodgkin lymphoma, and
the Ann Arbor staging system is used to
provide treatment planning information
and aid response assessment.
Pathology and genetics
Lymphomas constitute a diverse range of
diseases (Table 5.10). Advances in molecular
biology, genetics and immunology
have meant that there have been profound
changes in the classification of
neoplasms of lymphoid cells over the last
20 years. In the Revised European-
American Lymphoma classification system,
three broad categories are recognized:
Hodgkin disease and T-cell and Bcell
non-Hodgkin lymphomas. A WHO
classification has recently been published
[3]; prior to this the International Working
Formulation (IWF) was the most widely
used classification.
Non-Hodgkin lymphomas are derived
from B or T lymphocytes. In Western
countries, B-cell tumours are more common
(about 75% of cases), whereas T-cell
tumours are less common but are generally
more biologically aggressive. T-cell
tumours are relatively more common in
Table 5.10 Frequency of various types of non-Hodgkin lymphoma.
East Asia. A follicular lymphoma is
defined by the retention of the follicles
within a lymph node (Fig. 5.102), whereas
a diffuse lymphoma results from the infiltration
of the node with effacement of the
follicles by the malignant cells. The size of
the malignant lymphocytes is also important.
In contrast, Hodgkin disease is characterized
by the presence of multinucleate,
giant so-called “Reed-Sternberg” cells,
which may be rare in a particular biopsy
specimen and the surrounding cell proliferation.
The Revised European-American
Lymphoma classification [4] also covers
Hodgkin disease; four histological subtypes
of Hodgkin disease are recognized:
nodular sclerosing, mixed cellularity, lymphocyte
predominance and lymphocyte
depletion.
Many cytogenetic and molecular abnormalities
in non-Hodgkin lymphoma, in
particular Burkitt lymphoma, are caused
by a translocation of the oncogene C-
MYC from chromosome 8 to either the
immunoglobulin heavy chain region on
chromosome 14 or to one of the light
chain loci on chromosomes 2 or 22 [5].
Technological innovations, such as
microarrays, are revolutionizing diagnosis
(Fig. 5.105).
Genetic abnormalities in Hodgkin disease
are less frequently described, perhaps
due to the paucity of malignant cells in
the biopsy specimen.
Diagnosis % of total cases
Diffuse large B-cell lymphoma 30.6
Follicular lymphoma 22.1
MALT lymphoma 7.6
Mature T-cell lymphomas (except ALCL) 7.6
Chronic lymphocytic leukaemia/small lymphocytic 6.7
lymphoma
Mantle cell lymphoma 6.0
Mediastinal large B-cell lymphoma 2.4
Anaplastic large cell lymphoma (ALCL) 2.4
Burkitt lymphoma 2.5
Nodal marginal zone lymphoma 1.8
Precursor T lymphoblastic 1.7
Lymphoplasmacytic lymphoma 1.2
Other types 7.4
Lymphoma
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