Invasive breast carcinoma - IARC

Mesenchymal tumours
M. Drijkoningen J.P. Bellocq
F.A. Tavassoli
S. Lanzafame
G. Magro G. MacGrogan
V. Eusebi J.L. Peterse
M. Devouassoux-Shisheboran
Definition
Benign and malignant mesenchymal
tumours morphologically similar to those
occurring in the soft tissues as well as
those occurring predominantly in the
breast.
Benign vascular tumours
Haemangioma
Definition
A benign tumour or malformation of
mature vessels.
ICD-O code 9120/0
Epidemiology
Haemangiomas of the breast have been
described in both male and female
patients from 18 months to 82 years old
{1373,2874}. They rarely present as palpable
lesions but an increasing number
of non-palpable mammary haemangiomas
are nowadays detected by
breast imaging {3077}. Incidental "perilobular"
haemangiomas are found in
1.2% of mastectomies and 4.5% of
benign breast biopsies {2443} and 11%
in a series of post mortem cases (age
range 29–82 years) {1633}.
Macroscopy
Rarely palpable, the lesions are well circumscribed
and vary from 0.5-2 cm with
a reddish-brown spongy appearance.
Histopathology
Symptomatic haemangiomas may be of
cavernous, capillary or venous subtypes
{2435,2611}. Cavernous haemangioma
is the most common type; it consists of
dilated thin walled vessels lined by flattened
endothelium and congested with
blood. Thrombosis may be present
with papillary endothelial hyperplasia
( M a s s o n ’s phenomenon) {1946}. Dystrophic
calcification may be found in organizing
thrombi as well as in the stroma
between the vascular channels. Capillary
haemangiomas are composed of nodules
of small vessels with a lobular
arrangement around a larger feeding
vessel. The intervening stroma is fibrous.
The endothelial lining cells may have
p rominent hyperc h romatic nuclei but
without tufting or a solid spindle cell
growth pattern. Venous haemangiomas
consist of thick walled vascular channels
with smooth muscle walls of vary i n g
thickness {2435}.
In perilobular haemangiomas, the lobulated
collections of thin-walled, wide vascular
channels are seen within the
intralobular stroma. Expansion into the
extralobular stroma and adjacent adipose
tissue is often present. The vascular
channels are lined by flattened
endothelium without a surrounding muscle
layer {1373}. Occasional cases with
p rominent hyperc h romatic endothelial
nuclei have been described and designated
atypical haemangiomas {1225}.
An anastomosing growth pattern, papill
a ry endothelial proliferations and
mitoses are absent and their presence
should arouse suspicion and care f u l
exclusion of an angiosarcoma.
Prognosis and predictive factors
Recurrence, even after incomplete excision,
has not been re p o rted. Care f u l
evaluation of the whole lesion to exclude
a well diff e rentiated angiosarcoma is
indicated in all symptomatic vascular
breast lesions.
Angiomatosis
Definition
A diffuse excessive proliferation of well
f o rmed vascular channels affecting a
large area in a contiguous fashion.
Synonym
Diffuse angioma.
Epidemiology
This very rare benign vascular lesion
may be congenital. Most cases have
been described in women between 19
and 61 years old {1921,2416}. One case
was in a male.
Fig. 1.132 Perilobular haemangioma. Thin walled vessels lined by flattened endothelium are seen within the
intralobular stroma.
Clinical features
Angiomatosis presents as a breast mass.
Rapid increase in size has been described
in a woman during pregnancy {76}.
Mesenchymal tumours
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