Invasive breast carcinoma - IARC

A
B
C
Fig. 4.30 Leiomyosarcoma. A This tumour exhibits typical coagulative tumour cell necrosis on the right. This pattern of necrosis features an abrupt transition from
viable tumour cells to necrotic tumour cells without intervening collagen or granulation tissue. B This tumour has a low level of atypia. This degree of atypia should
prompt careful search for more diagnostic features. C A high level of atypia and apotosis is apparent in this tumour. D Leiomyosarcoma with intravascular tumour
growth. The differential diagnosis includes intravenous leiomyomatosis, low grade endometrial stroma sarcoma (ESS) and leiomyosarcoma with vascular invasion.
High power showed a poorly differentiated neoplasm with marked cytologic atypia and a high mitotic index. These are not features of low grade ESS or intravenous
leiomyomatosis.
D
Lipoleiomyoma 8890/0
Leiomyoma, growth pattern variants
Diffuse leiomyomatosis 8890/1
Intravenous leiomyomatosis 8890/1
Benign metastasizing leiomyoma 8898/1
Leiomyosarcoma
Definition
A malignant neoplasm composed of
cells demonstrating smooth muscle differentiation.
Epidemiology
L e i o m y o s a rcoma re p resents the most
common pure uterine sarcoma and comprises
slightly over 1% of all uterine
malignancies {1139}. The incidence of
leiomyosarcoma is reported to be 0.3-
0.4/100,000 women per year {1139}.
Leiomyosarcoma arises nearly exclusively
in adults. The median age of patients
with leiomyosarcoma was 50-55 years in
larger studies {947,1745}, and 15% of
the patients were younger than 40 years.
The risk factors for endometrial carcinomas
such as nulliparity, obesity, diabetes
mellitus and hypertension are not known
to relate to leiomyosarcoma.
Clinical features
L e i o m y o s a rcomas localized to the
uterus and leiomyomas produce similar
symptoms. Although a rapid increase in
the size of the uterus after menopause
may raise the possibility of leiomyosarcoma,
in fact sarcoma is not more
p revalent (less than 0.5%) in women
with "rapidly growing" leiomyomas
{1622,2187}.
L e i o m y o s a rcoma may spread locally,
regionally or by haematogenous dissemination.
This fact of natural history
has implications for both diagnosis and
management. Local and regional extension
may produce an abdominal or
pelvic mass and gastrointestinal or urin
a ry tract symptoms. Haematogenous
dissemination is most often to the lungs.
L e i o m y o s a rcoma is only infre q u e n t l y
diagnosed on endometrial samplings
{1622}.
Macroscopy
Leiomyosarcomas are characteristically
solitary intramural masses and are usually
not associated with leiomyomas.
L e i o m y o s a rcomas average 8.0 cm in
diameter and are fleshy with poorly
defined margins. Zones of haemorrhage
and necrosis characteristically interrupt
their grey-yellow or pink sectioned surface.
Mesenchymal tumours and related lesions 237