CHAPTER X CHAPTER 4 - Cancer et environnement

have cytoplasmic lacunae that contain
pink secretion or erythrocytes. The
cytotrophoblastic cells have pale to clear
cytoplasm with a single, irregularly
shaped nucleus with one or two prominent
nucleoli. Intermediate trophoblastic
cells have eosinophilic to clear cytoplasm
and single nuclei; they are larger
than cytotrophoblastic cells but may not
be readily discernible from them without
the use of immunohistochemical stains.
A
B
Immunoprofile
The syncytiotrophoblasts are positive for
hCG, alpha subunit of inhibin
{1664,2042} and epithelial membrane
antigen {1894}. Stains for hCG may also
highlight large cells that possibly represent
transitional forms between mononucleated
trophoblastic cells and syncytiotrophoblasts.
The intermediate trophoblastic
cells are positive for human
placental lactogen {1615, 1616} and, if
comparable to the gestational examples,
would be expected to stain for Mel-CAM
and HLA-G {2425}. All of the cell types
express cytokeratin, and placental alkaline
phosphatase shows patchy reactivity
in about one half of the cases.
Prognosis
Choriocarcinoma often disseminates
prior to its discovery, probably because
of its propensity to invade blood vessels.
As a consequence, the majority of
patients present with advanced stage
disease. It is this aspect of choriocarcinoma
that causes it to be associated with
a worse prognosis than most other forms
of testicular germ cell tumour. Additionally,
high levels of hCG correlate with a
C
Fig. 4.43 A Choriocarcinoma with typical hemorrhagic appearance. B Choriocarcinoma. C Choriocarcinoma.
Syncytiotrophoblastic cells with deeply eosinophilic cytoplasm and multiple, smudged appearing nuclei; they "cap"
aggregates of mononucleated trophoblastic cells with pale to clear cytoplasm. Note the fibrin aggregates.
D Choriocarcinoma. Positive HCG staining.
worse prognosis, likely reflecting a
greater tumour burden {7,281,575,1897}.
Trophoblastic neoplasms other than
choriocarcinoma
Two cases have been described of trophoblastic
testicular tumours that lacked
the biphasic pattern of choriocarcinoma
and were composed predominantly of
cytotrophoblastic cells (monophasic
choriocarcinoma) or intermediate trophoblastic
cells (similar to placental site
trophoblastic tumour). The latter consisted
of eosinophilic mononucleated
D
angioinvasive cells that were diffusely
immunoreactive for placental lactogen
and focally for chorionic gonadotrophin.
Follow-up was uneventful after orchiectomy
in both cases {2672}.
A favourable lesion described as cystic
trophoblastic tumour has been observed
in retroperitoneal metastases after
chemotherapy in eighteen patients; small
foci having a similar appearance may
rarely be seen in the testis of patients
with germ cell tumours who have not
received chemotherapy. The lesions consist
of small cysts lined predominantly by
A
B
Fig. 4.44 A Choriocarcinoma. This "monophasic" example has only rare multinucleated syncytiotrophoblastic cells and consists mostly of mononucleated cytotrophoblastic
and intermediate trophoblastic cells. B Placental site trophoblastic tumour. Mononucleated intermediate trophoblasts with eosinophilic cytoplasm.
242 Tumours of the testis and paratesticular tissue