Invasive breast carcinoma - IARC

Fig. 1.53 Secretory carcinoma. The tumour cells
have abundant pink eosinophilic cytoplasm.
as seen in the "tagetoid pattern" of ICL
described by Gad and Azzopardi {943}
is rarely evident.
Mitoses and necrotic areas are rare .
Ductal in situ carcinoma of either the
s e c re t o ry or low grade type may be
p resent, either at the margins or within
the tumour {2430}.
I m m u n o p r o f i l e
EMA, alpha lactalbumin and S-100 protein
are frequently expressed in SC
{323,1579,2430}. Estrogen re c e p t o r s
a re mostly undetectable.
Prognosis and predictive factors
SC has an extremely favourable pro g n o-
sis in children and adolescents but
seems slightly more aggressive in older
patients {2881}. Isolated re c u r rences in
c h i l d ren are exceptional {52}, but the
risk of nodal involvement is similar in
young and older patients {2430}.
A x i l l a ry lymph node metastases are
found in approximately 15% of patients
{2814} but metastases are confined to 4
lymph nodes at the most {52}.
Tumours less than 2 cm in size are
unlikely to pro g ress {2881}. Simple
m a s t e c t o m y, as opposed to excision of
the tumour, has led to a cure, with the
exception of the case re p o rted by Meis
{1860}. Recurrence of the tumour may
appear after 20 years {1519}, and prolonged
follow up is advocated. Fatal
cases are the exception {1519,2881}
and have never been re p o rted in child
re n .
Fig. 1.54 Secretory carcinoma. Abundant secretory
material is evident.
ICD-O code 8290/3
Historical annotation
Oncocyte (a Greek derived word )
means "swollen cell", in this case due to
an accumulation of mitochondria. The
t e rm oncocyte is used when mitochondria
occupy 60% of the cytoplasm
{990}. Oncocytic tumours can be seen
in various organs and tissues {2271,
2 4 0 5 } .
In oncocytes, mitochondria are diff u s e l y
dispersed throughout the cytoplasm
while in mitochondrion-rich cells they
a re grouped to one cell pole {2948}.
The pro p o rtion of oncocytes pre s e n t
within a tumour re q u i red to call it oncocytic
has been arbitrarily proposed by
various authors and varies from organ to
organ. In a small series of breast oncocytic
carcinomas, Damiani et al. {616},
using immunohistochemistry with an anti
mitochondrial antibody, found 70-90% of
the neoplastic cells packed massively
with immunoreactive granules.
Epidemiology
Only occasional cases have been
described {566,616}. However, the incidence
in the breast is probably underestimated
as oncocytes are easily overlooked
or misdiagnosed as apocrine elements
{615}. All described patients have
been over 60 years old. There is no
predilection for site. One case occurred
in a man {566}.
Macroscopy
The largest tumour measured 2.8 cm
{616}.
Histopathology
The tumours are all similar with defined,
c i rcumscribed borders and vary fro m
glandular to solid. The cells have abundant
cytoplasm filled with small
eosinophilic granules. Nuclei are monotonous
and round to ovoid with a conspicuous
nucleolus. Mitoses are not frequent.
In situ carcinomas with a papill
a ry appearance have been described
{ 6 1 6 } .
Differential diagnosis
Oncocytic carcinomas can be distinguished
from apocrine, neuro e n d o c r i n e
c a rcinomas and oncocytic myoepithelial
lesions {615,945,2013} by their immun
o p h e n o t y p e .
Oncocytic carcinoma
Definition
A breast carcinoma composed of more
than 70% oncocytic cells.
Fig. 1.55 Oncocytic carcinoma. Note well circumscribed nodule and cells with abundant eosinophilic cytoplasm.
Invasive breast carcinoma
43