Invasive breast carcinoma - IARC

used. Inflammatory conditions in the
b reast may mimic MALT lymphoma.
Prognosis and predictive factors
P r i m a ry breast lymphomas behave in a
way similar to lymphomas of corre s p o n-
ding type and stage in other sites.
Fig. 1.162 Lymphoblastic T-cell lymphoma, secondary
with lobular carcinoma-like appearance.
such as CD20 and CD79a; it is usually
bcl-2 positive but negative for CD10,
CD5 and CD23.
The translocation t(11;18)(q21;q21) has
been identified in many MALT lymphomas
although not in the few analysed
breast cases {2125}. Furthermore, trisomy
3 has been identified in a number
of MALT lymphomas at different sites but
breast cases were not included in the
study {3157}.
Follicular lymphoma
ICD-O code 9 6 9 0 / 3
Follicular lymphoma is another type of
lymphoma, which is included in re c e n t
p r i m a ry breast lymphoma series {113,
2 9 6 , 5 3 4 , 9 9 4 , 1 2 6 1 , 1 3 4 6 , 1 5 8 0 , 1 6 6 5 ,
1792}. It features neoplastic follicles
composed of centrocytes and centro b-
lasts in diff e rent pro p o rtions and may be
either grade 2 or 3, depending on the
number of centroblasts inside the neoplastic
follicles.
I m m u n o h i s t o c h e m i c a l l y, the lymphoma
cells show positivity for pan B antigens,
CD10 and bcl-2 but are negative for
CD5 and CD23. Follicular dendritic cells
in tight clusters positive for CD21 delineate
neoplastic follicles
Differential diagnosis
Malignant lymphoma of the breast may,
on routine haematoxilin and eosin
stained slides without using immunohistochemical
methods, be misdiagnosed
as carcinoma, particularly infiltrating
lobular or medullary carcinoma {18}. In
addition, some cases of granulocytic
s a rcoma (myeloid cell tumour) may be
confused with T cell lymphomas if only a
limited number of immunoreactions are
Metastasis to the breast from
extramammary malignancies
E p i d e m i o l o g y
Metastatic involvement of the breast
is uncommon as an initial symptom
of a non-mammary malignant neoplasm
{2424} accounting for 0.5-6% of
all b reast malignancies {982,3029}.
Women are affected five to six times
m o re frequently than men are {982,
3 0 2 9 } .
The clinically re p o rted incidence is
lower than that found at autopsy. It
is also higher when lymphoma and
leukaemia are included {2940,3029}.
Metastases within the breast are more
f requent in patients with known
disseminated malignancy (25-40%)
{2424}.
After lymphoma and leukaemia, malignant
melanoma {2135,2424,2872,
3020,3163} is the most common
s o u rce from an extramammary site followed
by rhabdomyosarcoma in child
ren or adolescents {393,1129}, and
tumours of lung, ovary, kidney, thyro i d ,
cervix, stomach and prostate {344,393,
9 8 2 , 1 1 1 1 , 1 1 2 9 , 1 5 3 0 , 1 7 5 8 , 2 1 3 4 , 2 4 8 1 ,
3 0 2 0 , 3 0 2 9 , 3 0 3 8 } .
Clinical features
The patient usually presents with a palpable
lesion, generally well circ u m-
scribed and rapidly growing to a size
of 1-3 cm. Tumours are solitary in 85%
of cases {2424}, usually situated in the
upper outer quadrant {778} and located
superf i c i a l l y. The lesions may be
bilateral (8-25%) {982} or multinodular.
They can rarely simulate an inflammat
o ry breast carcinoma {3020}. Axillary
lymph node involvement is fre q u e n t
{3029}. Mammographically, metastatic
lesions are well circumscribed and
without calcification excluding those
f rom ovarian lesions, making mammographic
diff e rentiation from medullary
or intracystic carcinoma difficult {1758,
2 1 3 4 , 3 0 3 8 } .
Fig. 1.163 Diffuse large cell lymphoma, secondary
to the breast.
M a c r o s c o p y
Typically the tumour is nodular, solitary
and well circ u m s c r i b e d .
M u l t i n o d u l a r i t y, when is present, would
be an important feature favouring a
metastatic carc i n o m a .
H i s t o p a t h o l o g y
It is important to recognize that the
morphology is not that of a primary
m a m m a ry carcinoma and to consider
the possibility of a metastasis from an
e x t r a m a m m a ry primary. This is part i c u-
larly crucial with the increasing use of
fine needle and tissue core biopsies
{982}.
H o w e v e r, some metastatic tumours
may have some similarities to primary
b reast neoplasms such as squamous,
mucinous, mucoepidermoid, clear cell
or spindle cell neoplasms, but they
lack an intraductal component and are
generally well circumscribed {2424}.
Differential diagnosis
I m m u n o h i s t o c h e m i s t ry is useful in separating
metastatic from primary carc i-
noma. The expression of horm o n a l
receptor and GCFDP-15 is in favour of
a breast primary carcinoma. A panel of
antibodies such as those to cytokeratin
7, 20, CA19-9, CA125, S100, vimentin
and HMB45 can be helpful depending
on the morphological appearance of
the lesion {778,2424}.
Prognosis and predictive factors
Metastatic involvement of the breast is
a manifestation of generalized metastases
in virtually all cases {2424,3020}.
The prognosis of patients with
metastatic disease in the breast is
dependent on the site of the primary
and the histological type {3029} .
Malignant lymphoma and metastatic tumours 109