Invasive breast carcinoma - IARC

A
B
Fig. 1.58 Adenoid cystic carcinoma. Immunostain
for laminin ( A ) decorates the basement membranes,
while cytoplasmic immunoreaction with
actin (B) unmasks the neoplastic myopithelial cell
component of the tumour.
tive for smooth muscle actin and
calponin {902} as well as keratin 14.
N e v e rtheless, most basaloid cells are
nondescript elements showing at elect
ron microscopy level few filaments and
organelles without specific feature s
{1507,2885}.
The cells that line the glandular lumina
a re cuboidal to spindle-shaped. When
cuboidal, they have blunt micro v i l l i
along the luminal margins (secre t o ry
type). When spindle-shaped, they
show abundant tonofilaments along
with microvillous cytoplasmic pro c e s s-
es such as to merit the design {2885}.
A c c o rd i n g l y, the secre t o ry type of cell
is keratin 7 positive, while the adenosquamous
cell is both keratin 7 and
14 positive {902}. These cells can
undergo squamous metaplasia as seen
in two of the cases re p o rted by
Lamovec et al. {1581}. Squamous
metaplasia is more common in bre a s t
ACC, but is virtually never seen in saliv
a ry gland ACC.
Prognosis and predictive factors
ACC is a low grade malignant tumour
generally cured by simple mastectomy.
Like its analogue in the salivary gland, it
r a rely spreads via the lymphatic stre a m .
Local re c u r rence is related to incomplete
excision, but patients have been
re p o rted to survive 16 years after the
excision of the re c u r rence {2223}. Only
two cases of axillary node metastases
have been re p o rted {2381,3094}.
Distant metastases occur in about 10%
of cases {544} and the lungs are frequently
involved.
Acinic cell carcinoma
Definition
Acinic cell carcinoma (ACCA) is the
b reast counterpart of similar tumours
that occur in the parotid gland and
show acinic cell (serous) diff e re n t i a-
t i o n .
ICD-O code 8550/3
Epidemiology
ACCA is a rare tumour. Seven cases
have been re c o rded {619,2561}. Other
c a rcinomas showing serous secre t i o n ,
p robably related to ACCA, have also
been re p o rted {1287,1483}. It aff e c t s
women between 35 and 80 years (mean
56 years) {619}.
Clinical features
ACCA presents as a palpable nodule
ranging from 2 to 5 cm size. One case
was discovered at mammography {619}.
H i s t o p a t h o l o g y
The tumours show a combination of
solid, microcystic and micro g l a n d u l a r
a reas. One case {619} was mostly solid,
and another {2404} had comedo-like
a reas with a peripheral rim of micro g-
landular structure s .
C y t o l o g i c a l l y, the cells have abundant,
usually granular, amphophilic to eosinophilic
cytoplasm. The granules may
be coarse and, bright red, re m i n i s c e n t
of those in Paneth cells or amphophilic.
H o w e v e r, clear "hypern e p h roid" cytoplasm
is not unusual. The nuclei are
i r re g u l a r, round to ovoid, with a single
nucleolus. The mitotic count varies and
can be as high as 15 mitoses/10 high
power fields {619}.
I m m u n o p r o f i l e
Most of the cells stain intensely with
anti-amylase, lysozyme chymotry p s i n ,
EMA and S-100 protein antisera {619}.
GCDFP-15, the mucoapocrine marker,
may also be focally positive.
U l t r a s t r u c t u r e
T h ree cases published were composed
of cells with cytoplasm filled by zymogen-like
granules measuring from 0.08
to 0.9 µm {619,2404,2561}.
Prognosis and predictive factors
None of the 7 re p o rted cases has died
of the tumour, although follow up was
limited (maximum 5 years). In two cases
a x i l l a ry lymph nodes contained metastases.
Treatments varied from neoadjuvant
chemotherapy with radical mastectomy
to lumpectomy alone.
Fig. 1.59 Acinic cell carcinoma showing aggregates
of cells with granular cytoplasm.
Fig. 1.60 Acinic cell carcinoma. Note the absence
of nuclear atypia.
Fig. 1.61 Acinic cell carcinoma, immunostain is
positive for lysozyme.
Invasive breast carcinoma
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