Invasive breast carcinoma - IARC

Fig. 2.08 Non-invasive peritoneal implant, epithelial
type. The implant consists of hierarchical branching
papillae within cystic spaces.
A
Fig. 2.09 Non-invasive peritoneal implant, desmoplastic type. A The implant is plastered on the peritoneal sur -
face without destructive invasion of the underlying tissue. B The epithelial aggregates show moderate cellular
atypia, and only a small portion of the implant is made up of epithelial cells.
B
contrast to carcinomas, SBTs generally
lack areas of necrosis and haemorrhage.
The cysts usually contain serous fluid,
but occasionally it is mucinous.
Tumour spread and staging
Stage I SBTs are confined to the inner surface
of the cyst with no spread beyond the
o v a ry. The staging of SBT follows the
TNM/FIGO system for carcinomas {51,
2 9 7 6 } .
Histopathology
The hallmarks of SBT that distinguish it
f rom a cystadenoma are the presence of
epithelial hyperplasia forming papillae
(with fibroedematous stalks), micro p a p i l-
lae associated with "detached" or "floating"
cell clusters and mild to moderate
nuclear atypia. It is distinguished from serous
carcinoma by the lack of destructive
s t romal invasion. The proliferating cells
v a ry from uniform, small cells with hyperc
h romatic nuclei to larger cells displaying
eosinophilic cytoplasm with variable and
generally low mitotic activity. Psammoma
bodies may be present but are less abundant
than in serous carc i n o m a s .
S B Ts are divided into typical and
m i c ro p a p i l l a ry types. The typical type
makes up the vast majority (90%) of SBTs
and has a classic branching papillary
Table 2.02
Serous borderline tumours. Histology of non-invasive vs. invasive peritoneal implants.
Non-invasive implants
Extension into interlobular fibrous septa of the omentum
Lacks disorderly infiltration of underlying tissue
Desmoplastic type
Proliferation appears plastered on peritoneal surface
Nests of cells, glands and or papillae proliferate in a prominent (>50%) background of dense
fibroblastic or granulation tissue with well defined margins
Epithelial type
Fills submesothelial spaces
Exophytic proliferations with hierarchical branching papillae
Composed predominantly of epithelial cells
No stromal reaction
Frequent psammoma bodies
Invasive implants (Sampling of underlying tissues is crucial for assessment of invasion)
Haphazardly distributed glands invading normal tissues such as omentum
Loose or dense fibrous reaction without significant inflammation
Generally dominant epithelial proliferation
Nuclear features resembling a low grade serous adenocarcinoma
Irregular borders
Aneuploidy
a rc h i t e c t u re and epithelial tufts overlying
the papillae. The micro p a p i l l a ry type
accounts for a small pro p o rtion (5-10%)
of tumours. This type shows focal or diffuse
proliferation of the tumour cells in
elongated, thin micropapillae with little or
no stromal support emerging dire c t l y
f rom the lining of a cyst, from large papillae
in a non-hierarchical pattern or fro m
the surface of the ovary. The micro p a p i l-
lae are at least five times as long as they
a re wide, arising directly from papillae
with a thick fibrous stalk (non-hierarc h i c a l
branching creating a "Medusa head-like
appearance"). Less common patterns are
c r i b r i f o rm and almost solid pro l i f e r a t i o n s
of non-invasive cells overlying papillary
stalks. A continuous 5-mm growth of any
of these three patterns is re q u i red for the
diagnosis of micro p a p i l l a ry SBT.
Up to 30% of SBTs are associated with
tumour on the outer surface of the ovary,
and about two-thirds are associated with
peritoneal implants {376,2615}.
Serous surface borderline tumour
In this variant, polypoid excrescences
formed by fine papillae with features of
SBT occupy the outer surface of the ovary.
S e rous borderline adenofibroma and
cystadenofibroma
In this variant, the epithelial lining of the
glands and/or cysts of the adenofibroma
or cystadenofibroma has the features of
SBT instead of benign epithelium.
Peritoneal implants
Two prognostically different types of peritoneal
implants have been identified,
non-invasive and invasive. The former is
further subdivided into desmoplastic and
epithelial types. Whereas the non-invasive
implants (regardless of their type)
have almost no negative influence on the
122 Tumours of the ovary and peritoneum