Invasive breast carcinoma - IARC

lipoma {1645}, hibernoma {2425} and
chondrolipoma {1774a}. Adenomas containing
glandular breast tissue such as
adenolipoma are considered as hamartomas
by some and variants of lipoma by
others.
Granular cell tumour
Definition
A tumour of putative schwannian origin
consisting of cells with eosinophlic granular
cytoplasm.
ICD-O code 9580/0
Epidemiology
Granular cell tumour (GCT) can occur in
any site of the body. It is relatively uncommon
in the breast {2114}. It occurs more
often in females than in males {430} with
a wide age range from 17-75 years {325,
617,668,3090} GCT is a potential mimicker
of breast cancer, clinically, radiologically
and grossly {608,617,995,2549}.
Clinical features
GCT generally presents as a single, firm,
painless mass in the breast parenchyma
but may be superficial causing skin
retraction and even nipple inversion,
w h e reas location deep in the bre a s t
p a renchyma may lead to secondary
involvement of the pectoralis fascia.
Rarely, patients have simultaneous GCTs
occurring at multiple sites in the body,
including the breast {1920,1922}.
Imaging typically shows a dense mass
with stellate margin.
Macroscopy
GCT appears as a well circumscribed or
infiltrative firm mass of 2–3 cm or less
with a white to yellow or tan cut surface.
H i s t o p a t h o l o g y
The histology is identical to that seen in
GCT at other sites of the body. There is
an infiltrating growth pattern, even in
lesions, which appear circumscribed on
g ross examination. The cellular component
is composed of solid nests, clusters
or cords of round to polygonal cells
with coarsely granular, eosinophilic periodic
acid-Schiff (PAS) positive (diastase
resistant) cytoplasm. due to the pre s-
ence of abundant intracytoplasmic
lysosomes. Aw a reness that GCT can
occur in the breast is essential.
I m m u n o reactivity with S-100 is important
in confirming the diagnosis of GCT;
lack of positivity for cytokeratins
excludes breast carc i n o m a .
Prognosis and predictive factors
The clinical behaviour of GCT is usually
benign following complete surgical
excision. Rare l y, lymph node metastases
have been re p o rted {668}. In contrast,
a malignant course should be
expected in the extremely rare malignant
mammary GCTs which show
nuclear pleomorphism, mitoses and
n e c rosis {468}.
Benign peripheral
nerve sheath tumours
D e f i n i t i o n
Benign peripheral nerve sheath
tumours (BPNST) include three distinct
lesions usually occurring in the peripheral
nerves or soft tissues: schwannomas
composed of diff e re n t i a t e d
Schwann cells; neuro f i b romas consisting
of a mixture of Schwann cells,
perineurial like cells and fibroblasts and
p e r i n e u romas composed of perineural
cells.
ICD-O codes
Schwannoma 9560/0
Neurofibroma 9540/0
Epidemiology
The breast is only rarely the primary site
of BPNST. There are only a few case
reports of schwannomas {881,953,1081}
and neuro f i b romas {1223,1675,2645},
but to our knowledge primary perineuroma
of the breast has not been recorded.
Since neurofibromas may be part of neurofibromatosis
type I (NF1), follow-up is
needed because of the potential for
malignant degeneration. The occurrence
of breast cancer in the context of breast
neurofibromas has been reported {1948}.
The age of patients at diagnosis is wide,
ranging from 15 to 80 years with a prevalence
of females.
Clinical features
The lesions present as a painless nodule
and the pathology and immunophenotype
is identical to their counterparts at
other sites of the body.
Angiosarcoma
Definition
A malignant tumour composed of neoplastic
elements with the morphological
properties of endothelial cells.
ICD-O code 9120/3
Synonyms
These tumours include lesions which
were formerly termed haemangiosarcoma,
haemangioblastoma, lymphangiosarcoma
and metastasizing haemangioma.
Lymphangiosarcomas probably
exist as a specific sarcoma of lymphatic
endothelium but, at present, there is no
A
B
Fig. 1.140 Primary mammary angiosarcoma. A, B Grade I (well differentiated) angiosarcoma showing interanastomosing channels containing red blood cells. The
endothelial nuclei are prominent and hyperchromatic, but mitotic figures are absent. C High grade (poorly differentiated) angiosarcoma. Solid aggregates of pleomorphic
endothelial cells surround vascular channels.
C
94 Tumours of the breast