CHAPTER X CHAPTER 4 - Cancer et environnement

Fig. 4.28 Spermatocytic seminoma with sarcoma.
Cut section: irregular, focally fibrotic, vaguely
multinodular, variegated white to tan surface with
foci of hemorrhage.
vival of one year. Only two have survived
more than a year without disease.
Systemic therapy has no effect {347,783,
1649 ,2646}.
Embryonal carcinoma
Definition
A tumour composed of undifferentiated
cells of epithelial appearance with abundant
clear to granular cytoplasm and a
variety of growth patterns.
ICD-O code 9070/3
Synonym
Malignant teratoma, undifferentiated.
Epidemiology
Embryonal carcinoma occurs in pure
form and as a tumour component in
germ cell tumours of more than one histologic
type (mixed germ cell tumours).
In pure form embryonal carcinoma comprises
only 2-10% while it occurs as a
component in more than 80% of mixed
germ cell tumours {1808}.
Clinical features
Signs and symptoms
It occurs first at puberty and has a peak
incidence around 30 years of age, which
is approximately 10 years before the
peak incidence of classical seminoma. A
painless swelling is the commonest clinical
feature, though because of their
propensity to grow faster than seminoma,
they are more prone to present with testicular
pain, which may mimic torsion. It
may be found in a testis, which had been
traumatized but did not appropriately
resolve. Some patients present with
symptoms referable to metastases
and/or gynaecomastia.
Imaging
Embryonal carcinoma is often smaller
than seminoma at the time of presentation
and more heterogeneous and ill
defined. The tunica albuginea may be
invaded and the borders of the tumour
are less distinct, often blending imperceptibly
into the adjacent parenchyma.
They are indistinguishable from mixed
germ cell tumours.
Macroscopy
Embryonal carcinoma causes a slight or
moderate enlargement of the testis often
with distortion of the testicular contour.
The average diameter at presentation is
4.0 cm. Local extension into the rete
testis and epididymis or even beyond is
not uncommon. The tumour tissue is soft
and granular, grey or whitish to pink or
tan often with foci of haemorrhage and
necrosis. It bulges extensively from the
cut surface and is often not well demarcated
from the surrounding testicular tissue.
It may contain occasional fibrous
septae and ill defined cysts or clefts
{1201,2664}.
A
B
Fig. 4.29 Spermatocytic seminoma. A Spermatocytic seminoma associated with sarcoma. B Sarcomatous
component of spermatocytic seminoma. C A sarcoma component that consists of a storiform pattern of
undifferentiated, spindle shaped tumour cells.
C
Histopathology
The growth pattern varies from solid and
syncytial to papillary with or without stromal
fibrovascular cores, forming clefts or
gland-like structures.
The tumour cells are undifferentiated, of
epithelial appearance and not unlike the
cells that form the inner cell mass of the
very early embryo. They are large, polygonal
or sometimes columnar with large
irregular nuclei that usually are vesicular
with a see through appearance, or they
may be hyperchromatic. One or more
large irregular nucleoli are present and
the nuclear membranes are distinct. The
cytoplasm is abundant, usually finely
granular but may also be more or less
clear. It stains from basophilic to amphophilic
to eosinophilic. The cell borders
are indistinct and the cells often tend to
crowd with nuclei abutting or overlapping.
Mitotic figures are frequent, includ-
236 Tumours of the testis and paratesticular tissue