Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc
Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc
Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc
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A<br />
B<br />
Fig. 4.27 Spermatocytic seminoma. A Note the three different cell types of spermatocytic seminoma. B Intratubular spread of spermatocytic seminoma.<br />
maturation stage specific markers,<br />
including SCP1 (synaptonemal complex<br />
protein 1), SSX (synovial sarcoma on X<br />
chromosome) and XPA (xeroderma pigmentosum<br />
type A1), have been demonstrated<br />
{2512}.<br />
Ultrastructure<br />
The cell membranes lack folds and<br />
indentations. There are intercellular<br />
bridges like those between primary spermatocytes<br />
{2226}. Gap junctions and<br />
macula adherens type junctions can be<br />
observed. The chromatin is either homogeneously<br />
dispersed or has dense condensations<br />
and nucleoli have net-like<br />
nucleolonema {2299}.<br />
Differential diagnosis<br />
Spermatocytic seminoma, when misinterpreted,<br />
is most frequently classified as<br />
typical seminoma or lymphoma. Seminoma,<br />
however, usually has a fibrous stroma,<br />
a lymphocytic and/or granulomatous<br />
stromal reaction and cells with abundant<br />
glycogen, PLAP positivity, and IGCNU<br />
component. Lymphoma has a predominant<br />
interstitial growth pattern and lacks<br />
the spireme chromatin distribution.<br />
Genetics<br />
The DNA content of spermatocytic seminoma<br />
is different from that of seminoma,<br />
including diploid or near hyperdiploid<br />
values {582,1832,2234,2568}. Small cells<br />
have been reported to be diploid or near<br />
diploid by cytophotometry {2555}, the<br />
intermediate cells have intermediate values<br />
and the giant tumour cells up to 42C.<br />
Haploid cells have not been reported<br />
{1385,2568}. These data are in keeping<br />
with the finding that spermatocytic seminoma<br />
cells show characteristics of cells<br />
undergoing meiosis, a feature that is<br />
diagnostically helpful {2512}. CGH and<br />
karyotyping show mostly numerical chromosomal<br />
aberrations. The gain of chromosome<br />
9 in all spermatocytic seminomas<br />
appears to be a nonrandom chromosome<br />
imbalance {2234}. The presence<br />
of common chromosomal imbalances<br />
in a bilateral spermatocytic seminoma<br />
and immunohistochemical characteristics<br />
{2512} suggests that the initiating<br />
event may occur during intra-uterine<br />
development, before the germ cells populate<br />
the gonadal ridges. This might<br />
explain the relatively frequent occurrence<br />
of bilateral spermatocytic seminoma<br />
(5% of the cases). No gene or genes<br />
involved in the pathogenesis of spermatocytic<br />
seminomas have been identified<br />
yet, although puf-8 recently identified in<br />
C. elegans might be an interesting candidate<br />
{2524}.<br />
Prognosis<br />
Only one documented case of metastatic<br />
pure spermatocytic seminoma has<br />
been reported {1646}.<br />
Spermatocytic seminoma with<br />
sarcoma<br />
Definition<br />
A spermatocytic seminoma associated<br />
with an undifferentiated or, less frequently,<br />
with a differentiated sarcoma.<br />
Clinical features<br />
Approximately a dozen cases of this<br />
tumour have been reported. The age<br />
range is 34-68 years. There is no familial<br />
association, and no etiologic agents<br />
have been identified. The typical patient<br />
has a slowly growing mass that suddenly<br />
enlarges within months of diagnosis.<br />
Fifty percent of patients have metastases<br />
at diagnosis. Levels of serum alpha-fetoprotein<br />
and human chorionic gonadotropin<br />
are normal.<br />
Macroscopy<br />
Typically the tumour is a large (up to 25<br />
cm), bulging mass with variegated cut<br />
surface exhibiting areas of induration,<br />
necrosis, and focal myxoid change.<br />
Histopathology<br />
The spermatocytic seminoma component<br />
frequently has foci of marked pleomorphism<br />
{647}, and is histologically<br />
contiguous with the sarcoma component.<br />
The sarcoma can exhibit various patterns<br />
- rhabdomyosarcoma, spindle cell sarcoma,<br />
and chondrosarcoma {347,783,<br />
1649,1800,2646}.<br />
Differential diagnosis<br />
The primary differential diagnosis is sarcomatous<br />
transformation of a testicular<br />
germ cell tumour {2665}. Absence of teratoma<br />
and recognition of the spermatocytic<br />
seminoma excludes this possibility.<br />
The differential diagnosis of a tumour<br />
where only the sarcoma component is<br />
sampled includes primary testicular sarcoma<br />
{408,2786,2950}, paratesticular sarcoma,<br />
and metastatic sarcoma or sarcomatoid<br />
carcinoma {510,753,769, 2146}.<br />
Tumour spread and prognosis<br />
The sarcomatous component metastasizes<br />
widely. Most patients die of<br />
metastatic tumour, with a median sur-<br />
Germ cell tumours<br />
235