Invasive breast carcinoma - IARC

ent and this is occasionally extensive. In
a minority of cases a distinct lymphoplasmacytoid
infiltrate can be identified.
Mixed type carcinoma
For a tumour to be typed as ductal NOS
it must have a non-specialized pattern in
over 50% of its mass as judged by thorough
examination of representative sections.
If the ductal NOS pattern comprises
between 10 and 49% of the tumour,
the rest being of a recognized special
type, then it will fall into one of the mixed
groups: mixed ductal and special type or
mixed ductal and lobular carc i n o m a .
Apart from these considerations there
are very few lesions that should be confused
with ductal NOS carcinomas.
Pleomorphic carcinoma
ICD-O code 8022/3
Fig. 1.13 Mixed infiltrating ductal and infiltrating lobular carcinoma. Two distinct morphologic patterns are
seen in this tumour, ductal on the left and lobular on the right.
Pleomorphic carcinoma is a rare variant
of high grade ductal NOS carc i n o m a
characterized by proliferation of pleomorphic
and bizarre tumour giant cells
comprising >50% of the tumour cells in
a background of adenocarcinoma or
a d e n o c a rcinoma with spindle and
squamous diff e rentiation {2683}. The
patients range in age from 28 to 96
years with a median of 51. Most
patients present with a palpable mass;
in 12% of cases, metastatic tumour is
the first manifestation of disease. The
mean size of the tumours is 5.4 cm.
Cavitation and necrosis occur in larger
t u m o u r s .
The tumour giant cells account for more
than 75% of tumour cells in most cases.
Mitotic figures exceed 20 per 10 high
power fields. All these tumours qualify as
grade 3 carcinomas. The intraepithelial
component displays a ductal arrangement
and is often high grade with necrosis.
Lymphovascular invasion is present
in 19% of cases.
Generally BCL2, ER and PR negative,
two thirds of these pleomorphic carcinomas
are TP53 positive, and one third are
S-100 protein positive. All are positive for
CAM5.2, EMA and pan-cytokeratin
(AE1/AE3, CK1). A majority (68%) is aneuploid
with 47% of them being triploid. A
high S-phase (>10%) is found in 63%.
Axillary node metastases are present in
50% of the patients with involvement of 3
or more nodes in most. Many patients
present with advanced disease.
Carcinoma with osteoclastic giant
cells
ICD-O code 8035/3
The common denominator of all these
c a rcinomas is the presence of osteoclastic
giant cells in the stroma {1089}.
The giant cells are generally associated
with an inflammatory, fibroblastic, hyper-
A
B
Fig. 1.14 Invasive ductal carcinoma: pleomorphic carcinoma. A Poorly differentiated cells without distinctive architecture often lead to misinterpretation of the
lesion as a sarcoma. B Immunostain for keratin (AE1/AE3 and LP34) confirms the epithelial nature of the process.
Invasive breast cancer
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