Invasive breast carcinoma - IARC

Unclassified sex cord-stromal
t u m o u r
D e f i n i t i o n
Sex cord-stromal tumours in which there
is no clearly predominant pattern of testicular
or ovarian differentiation {2605}.
E p i d e m i o l o g y
They account for 5-10% of tumours in
the sex cord - s t romal category.
Clinical features
The tumour may be estrogenic, andro g e-
nic or non-functional {2619,2701, 3196}.
H i s t o p a t h o l o g y
H i s t o l o g i c a l l y, the tumour cells show
p a t t e rns and cell types that are interm e-
diate between or common to granulosas
t romal cell tumours and Sert o l i - s t ro m a l
cell tumours.
Prognosis and predictive factors
The prognosis is similar to that of granulosa
cell tumours and SLCTs of similar
d e g rees of diff e rentiation {2619}.
Steroid cell tumours
D e f i n i t i o n
Tumours that are composed entirely or
p redominantly (greater than 90%) of cells
that resemble steroid horm o n e - s e c re t i n g
cells. This category includes the stro m a l
luteoma, steroid cell tumour, not furt h e r
classified and the Leydig cell tumours that
do not have another component.
ICD-O codes
S t e roid cell tumour, NOS 8670/0
Well diff e re n t i a t e d 8670/0
Malignant 8670 / 3
S t romal luteoma 8610 / 0
Leydig cell tumour 8650 / 0
Synonym and historical annotation
The designation "lipid cell tumour" is no
longer recommended because it is inaccurate
as well as nonspecific, since up to
25% of tumours in this category contain
little or no lipid {2605}. The term "steroid
cell tumour" has been accepted by the
World Health Organization (WHO)
because it reflects both the morphological
features of the neoplastic cells and
their propensity to secrete steroid hormones.
Steroid cell tumour,
not otherwise specified
D e f i n i t i o n
These are steroid cell tumours that cannot
be classified into one of the aforementioned
groups. It is probable that
some of these cases re p resent Leydig
cell tumours in which Reinke cry s t a l s
cannot be identified. Some may also
re p resent large stromal luteomas where
a parenchymal location can no longer
be established.
Clinical features
They are usually associated with androgenic
manifestations and occasionally
with estrogenic effects {1163}. Rare neoplasms
have also been associated with
p rogestogenic effects, Cushing synd
rome or other paraneoplastic synd
romes due to hormone secretion {3218}.
M a c r o s c o p y
These neoplasms are often large and are
usually well circumscribed, often having a
lobulated appearance. Occasional neoplasms
are bilateral. The sectioned surface
ranges from yellow to brown or black.
Especially in large tumours, areas of
haemorrhage and necrosis may be seen.
H i s t o p a t h o l o g y
These neoplasms are usually composed
of solid aggregates of cells with occasional
nests or trabeculae. Tumour cells
are polygonal with cytoplasm that is usually
granular and eosinophilic but which
may be vacuolated. Sometimes both cell
types may be present. Cytoplasmic lipofuscin
pigment may be identified. Nuclei
may be bland, but in some cases there is
considerable nuclear atypia and significant
numbers of mitotic figures may be
found. Areas of haemorrhage and necrosis
can be present. Intracytoplasmic lipid
can usually be identified with special
stains and rarely may be so abundant as
to result in a signet-ring appearance.
Occasional tumours contain a considerable
amount of fibrous stroma.
I m m u n o p ro f i l e
These neoplasms are usually immunoreactive
to alpha-inhibin and variably with
anti-cytokeratin antibodies and vimentin.
D i ff e rential diagnosis
Luteoma of pregnancy may mimic a
lipid-poor or lipid-free steroid cell
t u m o u r. The former is usually discovere d
Fig. 2.85 Hilus cell tumour. Note the typical tan
tumour in the hilus, well demarcated from the adjacent
ovary.
Fig. 2.86 Leydig cell tumour, non-hilus cell type.
The cells are large and polygonal. Note the two
large, rod-shaped crystals of Reinke.
in patients at caesarean section with a
t e rm pregnancy and typically occurs in
m u l t i p a rous Black patients in their third
or fourth decade. Also in the diff e re n t i a l
diagnosis are oxyphilic variants of a
number of other ovarian tumours, e.g.
struma ovarii, clear cell carcinoma, prim
a ry or secondary malignant melanoma
and carcinoid.
Prognosis and predictive factors
A p p roximately one-third of these neoplasms
are clinically malignant, and
they sometimes have extensive intraabdominal
spread at pre s e n t a t i o n .
Malignant tumours are more likely to be
g reater than 7 cm diameter, contain
a reas of haemorrhage and necro s i s ,
exhibit moderate to marked nuclear
atypia and have a mitotic count of two or
m o re per 10 high power fields.
O c c a s i o n a l l y, however, as with other
endocrine neoplasms, the behaviour
may be unpredictable, and tumours
lacking these histological features may
behave in a malignant fashion.
Stromal luteoma
D e f i n i t i o n
S t romal luteomas are clinically benign
s t e roid cell neoplasms of ovarian stro-
160 Tumours of the ovary and peritoneum