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Metaplastic
breast
cancer,
also
called
metaplastic
carcinoma
of the
breast,
is a
rare
type of
breast
cancer.
Cancer
begins
when
normal
cells in
the
breast
begin to
change
and grow
uncontrollably,
forming
a mass
called a
tumor. A
tumor
can be
benign
(noncancerous)
or
malignant
(cancerous,
meaning
it can
spread
to other
parts of
the
body).
About
the
breast
The
breast
is
mainly
composed
of fatty
tissue.
Within
this
tissue
is a
network
of
lobes,
which
are made
up of
tiny,
tube-like
structures
called
lobules
that
contain
milk
glands.
Tiny
ducts
connect
the
glands,
lobules,
and
lobes,
carrying
the milk
from the
lobes to
the
nipple,
located
in the
middle
of the
areola
(darker
area
that
surrounds
the
nipple
of the
breast).
Blood
and
lymph
vessels
run
throughout
the
breast;
blood
nourishes
the
cells,
and the
lymph
system
drains
bodily
waste
products.
The
lymph
vessels
connect
to lymph
nodes,
the
tiny,
bean-shaped
organs
that
ordinarily
help
fight
infection.
About
metaplastic
breast
cancer
Metaplastic
breast
cancer
describes
a cancer
that
begins
in one
type of
cell
(such as
those
from the
glands
of the
breast)
and
changes
into
another
type of
cell. It
is very
different
from the
typical
ductal
or
lobular
breast
cancer.
Most
cases of
metaplastic
breast
cancer
start in
the
epithelial
cells,
and then
change
into
squamous
(nonglandular)
cells.
Because
the
cells
that
give
rise to
metaplastic
breast
cancer
are not
part of
the
normal
breast
gland,
this
cancer
does not
have
estrogen
receptors
(ERs),
progesterone
receptors
(PRs),
or HER2
(a
protein
found in
20% of
ductal
and
lobular
breast
cancers).
Metaplastic
breast
cancer
can
spread
to the
lymph
nodes
and
other
areas of
the
body,
especially
the
lungs.
At the
time of
diagnosis,
metaplastic
breast
cancer
is
considered
an
invasive
cancer,
meaning
that it
has
already
spread
beyond
the duct
or lobe.
Find out
more
about
basic
cancer
terms
used in
this
section. |
