Invasive breast carcinoma - IARC

express thrombomodulin and have been
immunonegative for cytokeratin 20 in
most, but not all, studies {2085,2115,
2116,2371,2758}.
Benign Brenner tumours have an
endocrine cell component demonstrable
with immunostains for chromogranin A,
serotonin and neuron specific enolase
{45,2530}.
Somatic genetics
There is one report of a 12q14-21 amplification
in a benign Brenner tumour
{2207}.
A
Squamous cell lesions
Squamous cell carcinoma
Definition
Malignant ovarian tumour composed of
squamous epithelial cells that is not of
germ cell origin.
B
Fig. 2.53 Benign Brenner tumour. A One of the transitional cell nests is cystic and contains eosinophilic
secretions. B One of the transitional cell nests contains a central lumen lined by mucinous columnar epithelium.
C This transitional cell nest shows scattered grooved, coffee bean shaped nuclei.
such patients may present with non-specific
signs and symptoms referable to a
pelvic mass. Occasionally, Bre n n e r
tumours are associated with manifestations
related to the elaboration of estrogens
or androgens by the stromal component
of the tumour.
Macroscopy
The typical benign Brenner tumour is
small, often less than 2 cm, but, regardless
of size, is well circumscribed with a
firm, white, sometimes gritty sectioned
surface due to focal or extensive calcification.
Small cysts are common, and a
r a re tumour is predominately cystic.
B renner tumours are associated with
another tumour type, usually mucinous
cystadenoma, in 25% of cases
Tumour spread and staging
Only 7-8% of benign Brenner tumours
are bilateral {753}
Histopathology
Benign Brenner tumours are characterized
by nests and islands of transitional
type epithelial cells with centrally
C
grooved, "coffee bean" nuclei, abundant
amphophilic to clear cytoplasm and distinct
cell membranes growing in a dominant
fibromatous stroma. The nests may
be solid or exhibit central lumina containing
densely eosinophilic, mucin-positive
material. The lumina may be lined by
transitional type cells or mucinous, ciliated
or nondescript columnar cells.
Variably sized cysts lined by mucinous
epithelium, either pure or overlying transitional
epithelium are common in benign
B renner tumours. Benign Bre n n e r
tumours with crowded transitional nests
and cysts with a prominent mucinous
component, sometimes with complex
gland formations, are termed "metaplastic
Brenner tumour" by some and not
mixed epithelial tumours {2461} since the
epithelial components are admixed
rather than separate. Their recognition
avoids confusion with borderline or
malignant Brenner tumours.
Immunoprofile
Benign Brenner tumours show some
u rothelial diff e rentiation evidenced by
uroplakin expression, but they do not
ICD-O code 8070/3
Epidemiology
The age of women with squamous cell
c a rcinoma, pure or associated with
endometriosis, has ranged from 23-90
years.
Macroscopy
Most squamous cell carcinomas are
solid, although in some instances cystic
components predominate.
Histopathology
Histologically, squamous cell carcinomas
are usually high grade and show a variety
of patterns including papillary or
polypoid, cystic, insular, diffusely infiltrative,
verruciform or sarcomatoid. They
must be distinguished from endometrioid
adenocarcinomas with extensive squamous
differentiation and from metastatic
squamous cell carcinoma from the cervix
and other sites {3198}.
Histogenesis
Most squamous cell carcinomas arise
from dermoid cysts and are classified in
the germ cell tumour category. Less
commonly, they occur in association with
endometriosis {1624,1828,1973,2255,
2902}, as a component of malignant
Brenner tumour {2460} or in pure form
{2255} and are considered to be surface
e p i t h e l i a l - s t romal tumours. Some pure
Surface epithelial-stromal tumours 143