Invasive breast carcinoma - IARC

Fig. 1.119 Sclerosing adenosis with a radial scar.
Prognosis and predictive factors
It has been suggested that these
lesions are pre-neoplastic or even re p-
resent early invasive carc i n o m a s
{1668} and also that they may re p resent
a marker of risk for the subsequent
development of carcinoma. Follow up
studies, however, have been few and
c o n t r a d i c t o ry {843,1320} suggesting
that an apparent risk is related to the
various patterns of associated intraductal
hyperplasia. It is doubtful that,
without epithelial proliferation, there is
a risk of the subsequent development
of invasive carcinoma. In larger lesions
the risk may be slightly higher as the
i n c rease in size is usually due to various
forms of epithelial hyperplasia. A
high incidence of atypical hyperplasia
and carcinoma (both in situ and invasive)
has been re p o rted in CSLs
detected by mammography, part i c u-
larly in lesions measuring over 0.6 cm,
and in women over 50 years old
{ 7 1 9 , 2 7 2 5 } .
Fig. 1.120 Radial scar. A central fibrous scar is
surrounded by epithelial proliferation.
Tubular adenoma
Definition
Benign, usually round, nodules formed by
a compact proliferation of tubular struct
u res composed of the typical epithelial
and myoepithelial cell layers. The epithelial
cells are similar to those of the norm a l
resting breast, but adenoma variants
have been described where these show
apocrine or lactating features.
ICD-O code 8211/0
Epidemiology
Tubular adenomas occur mainly in young
females {1202,1211,1919,2074}. They
rarely occur before menarche or after
menopause {1600,2025}. They reportedly
account for 0.13 to 1.7% of benign
b reast lesions {1202,1211,2874}. Patients
with lactating adenomas are nursing
mothers who have noted an area of
increased firmness, either during lactation
or, earlier, during pregnancy.
Clinical features
The clinical and imaging features are
usually those of fibroadenoma.
Macroscopy
The tumours are firm, well circumscribed
and homogeneous with a uniform, yellowish,
cut surface.
Histopathology
The lesion is composed entirely of small,
round tubules with little intervening stroma.
The latter may contain a few lymphocytes.
The epithelial cells are uniform,
Mitotic activity is usually low. The tubular
lumen is small and often empty, but
eosinophilic proteinaceous material can
be present. Occasional larger tubules
give rise to thin branches. Combined
tubular adenoma and fibroadenoma has
been described {1202,2874}. Rare cases
have been described of in situ and/or
invasive carcinoma involving adenomas
(tubular or lactating) {561,1202,1211,
2442}, a phenomenon also known to
occur in fibroadenomas.
Lactating adenoma
ICD-O code 8204/0
During pregnancy and lactation, the
epithelial cells of a tubular type adenoma
may show extensive secre t o ry
changes warranting a designation of
lactating adenoma {1332,2074}. It has
been suggested that such lesions re p resent
focal accumulation of hyperplastic
l o b u l e s .
A
Fig. 1.121 Tubular adenoma. A The fibrous capsule is present in the left upper corner. B Higher magnification displays epithelial and myoepithelial cell lining of the tubules.
B
84 Tumours of the breast