Follicular
lymphoma
Follicular
lymphoma
(FL) is the
most common
of the
indolent
non-Hodgkin's
lymphomas.
It is
defined as a
lymphoma of
follicle
center
B-cells (centrocytes
and
centroblasts),
which has at
least a
partially
follicular
pattern. It
is positive
for CD10.
Morphology
The tumor
is composed
of follicle
center
cells,
usually a
mixture of
centrocytes
(cleaved
follicle
center
cells,
"small
cells") and
centroblasts
(large
noncleaved
follicle
center
cells,
"large
cells").
Centrocytes
typically
predominate;
centroblasts
are usually
in the
minority,
but by
definition
are always
present.
Rare
lymphomas
with a
follicular
growth
pattern
consist
almost
entirely of
centroblasts.
Occasional
cases may
show
plasmacytoid
differentiation
or foci of
marginal
zone or
monocytoid
B-cells.
Causes
A
translocation
between
chromosome
14 and 18
results in
the
overexpression
of the bcl2
gene. This
overexpression
causes a
blockage of
apoptosis,
or
programmed
cell death.
This
translocation
has been
associated
with the
development
of
Follicular
lymphoma.
Treatment
There is no
consensus
regarding
the best
treatment
algorithm,
but
watch-and-wait
policies,
alkylators,
anthracycline-containing
regimens (eg.
CHOP),
rituximab,
autologous
and
allogeneic
hematopoietic
stem cell
transplantation
have all
been
applied. The
disease is
regarded as
incurable
(although
allogeneic
stem cell
transplanation
may be
curative,
the
mortality
from the
procedure is
too high to
be a first
line
option). The
exception is
localised
disease,
which can be
cured by
local
irradiation.
The typical
pattern is
one of good
responses
from
treatment,
followed by
relapses
some years
later.
Median
survival is
around 10
years, but
the range is
wide, from
less than
one year, to
more than 20
years. Some
patients may
never need
treatment. |
