Invasive breast carcinoma - IARC

Differential diagnosis
There may be a discrepancy between
clinical presentation with inflammatory
features and presence of dermal lymphatic
emboli. Dermal vascular emboli
may not be present in a biopsy taken
from erythematous or oedematous area,
or may be present in skin beyond the
clinical skin changes. The skin biopsy
will usually also show dermal lymphatic
dilatation. The clinical features of inflammatory
carcinoma are generally regarded
as specific but underlyng true inflammatory
conditions should be excluded if
histological confirmation is not achieved.
Fig. 1.64 Sebaceous carcinoma. Cells with moderate amounts of eosinophilic or abundant microvacuolated
cytoplasm and variably compressed nuclei resembling lipoblasts are admixed.
istic clinical picture is insufficient to qualify
as inflammatory carc i n o m a .
ICD-O code 8530/3
Epidemiology
The age distribution is similar to ductal
NOS carcinoma and breast carcinoma in
general {1095,2384}. There is no re c o g-
nized specific association with younger
age and pregnancy but the phenomenon
of peritumoural lymphatic vascular invasion
is found more frequently in younger
women {1095,2795}. The re p o rted frequency
of an inflammatory presentation of
p r i m a ry breast carcinoma varies between
1 and 10%, being influenced by the diagnostic
criteria (clinical or pathological)
and the nature of the re p o rting centre
(local population clinical centre versus
t e rt i a ry referral centre) {769,1641,2517}.
Clinical features
The clinical findings include diffuse erythema,
oedema, peau d’orange, tenderness,
induration, warmth, enlargement
and in some cases a palpable ill defined
mass. The diagnosis is based on clinical
features and should be confirmed by
biopsy. Dermal lymphatic tumour emboli
are not always found in small diagnostic
skin biopsy samples {724,2384}.
Histopathology
Despite the name, inflammatory carc i n o-
ma is not associated with any significant
d e g ree of inflammatory cell infiltration and
is not an inflammatory condition. The
cutaneous signs are produced as a consequence
of lymphatic obstruction and
consequent oedema, which pro d u c e
signs mimicking an inflammatory pro c e s s .
I n f l a m m a t o ry signs can be the primary
clinical presenting abnormality (primary
i n f l a m m a t o ry carcinoma) or develop as a
consequence of tumour re c u r rence (seco
n d a ry inflammatory carc i n o m a ) .
Histologically the underlying invasive
carcinoma is not regarded as having
specific histological features, the majority
of tumours have ductal NOS and are of
grade 3 morphology {1708,1851}. These
tumours often have an associated lymphoid
infiltrate usually of mature lymphocytes
and plasma cells, a low frequency
of estrogen receptor positivity {445,1490}
and ERBB2 overexpression {1074}. The
skin often shows co-existing feature s
associated with lymphatic obstruction
including separation of collagen fibres
with broadening of the reticular dermal
layer due to oedema. Involved dermal
lymphatics may have an associated
lymphoplasmacytic infiltrate {2427}.
Secondary or recurrent inflammatory carcinoma
has been shown to be associated
more with ductal NOS and apocrine
histological types of breast carcinoma
and is rare following presentation with
other types, papillary, medullary and
mucinous {2384}. The skin may also
show stromal metastatic deposits of
tumour particularly in secondary or
recurrent inflammatory carcinoma.
Prognosis and predictive factors
Prior to the introduction of systemic
therapy the prognosis of inflammatory
carcinoma even when treated by mastectomy,
was very poor with 5 year survival
under 5% {1052,2384}. Use of systemic
chemotherapy has produced an
improvement in survival figures reported
as 25 to 50% at 5 years {406,828,1805,
1907,2154}. In cases treated with neoadjuvant
chemotherapy or radiotherapy,
residual tumour, including intravascular
emboli, are usually present in the mastectomy
specimen even when a clinical
response has been observed {2427}.
Mastectomy and radiotherapy are considered
beneficial for initial local control
and palliation of symptoms {406,582,
2243}. There are no consistent findings
with respect to influence of additional
clinical features such as presence of
a clinical mass or findings in skin biopsy
on survival. However, response to chemotherapy
and radiotherapy, and pathological
response have been shown to be
associated with improved disease free
survival {473,828,841,1826}.
Bilateral breast carcinoma
Definition
A synchronous breast cancer is one
detected within two months of the initial
primary tumour.
A p p roximately 5-10% of women tre a t e d
for breast cancer will have either sync
h ronous bilateral cancers or will develop
a subsequent contralateral bre a s t
cancer (CBC) {448,872,1219,1491,
2383}. The prevalence of synchro n o u s
bilateral breast cancer is appro x i m a t e l y
1% of all breast cancers {448,648,872,
1491,1936}. An increase in the detection
48 Tumours of the breast