Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

senting symptom: back or abdominal
pain, gastrointestinal problems, cough
or dyspnoea. Gynecomastia may also
be seen in about 5% of cases.
Occasionally, extensive work ups have
resulted without an adequate examination
of the genitalia.
Imaging
Ultrasound (US) is the primary imaging
modality for evaluating scrotal pathology.
It is easily performed and has been
shown to be nearly 100% sensitive for
identifying scrotal masses. Intratesticular
versus extratesticular pathology can be
differentiated with 98-100% sensitivity
{211,378,2194}. The normal testis has a
homogeneous, medium level, granular
echo texture. The epididymis is isoechoic
to slightly hyperechoic compared to the
testis. The head of the epididymis is
approximately 10-12 mm in diameter and
is best seen in the longitudinal plane,
appearing as a slightly rounded or triangular
structure on the superior pole of the
testis. Visualization of the epididymis is
often easier when a hydrocele is present.
When evaluating a palpable mass by
ultrasound, the primary goal is localization
of the mass (intratesticular versus
extratesticular) and further characterization
of the lesion (cystic or solid). With
rare exception, solid intratesticular masses
should be considered malignant.
While most extratesticular masses are
benign, a thorough evaluation must be
performed. If an extratesticular mass has
any features suspicious of malignancy it
must be removed.
The sonographic appearance of testicular
tumours reflects their gross morphology
and underlying histology. Most
tumours are hypoechoic compared to the
surrounding parenchyma. Other tumours
can be heterogeneous with areas of
increased echogenecity, calcifications,
and cyst formation {211,378,927,1007,
2194,2347}. Although larger tumours
tend to be more vascular than smaller
tumours, colour Doppler is not of particular
use in tumour characterization but
does confirm the mass is solid {1126}.
Epididymal masses are more commonly
benign. It can, however, be difficult to differentiate
an epididymal mass from one
originating in the spermatic cord or other
paratesticular tissues. This is especially
true in the region of the epididymal body
and tail where normal structures can be
difficult to visualize.
Since ultrasound is easily performed,
inexpensive, and highly accurate, magnetic
resonance (MR) imaging is seldom
needed for diagnostic purposes. MR
imaging can, however, be a useful problem
solving tool and is particularly helpful
in better characterizing extratesticular
solid masses {507,2362}. Computed
tomography (CT) is not generally useful
for differentiating scrotal pathology but is
Table 4.02
Overview of the three different subgroups of testicular germ cell tumours, characterized by age at clinical
presentation, histology of the tumour, clinical behaviour and genetic changes.
Age of the patient at
clinical presentation
(years)
Adolescents and
young adults
(i.p. 15-45)
Elderly
(i.p. over 50)
Histology of the
tumour
0-5 Teratoma and/or
yolk sac tumour
Seminoma
Non-seminoma
(embryonal carcinoma,
teratoma, yolk
sac tumour,
choriocarcinoma)
Spermatocytic
Seminoma
* found in all invasive TGCTs, regardless of histology.
Clinical behaviour
Benign
Malignant
Malignant
Malignant
Benign, although can
be associated with
sarcoma
Chromosomal
imbalances
Not found
Loss: 6q
Gain: 1q , 20q, 22
Aneuploid, and
Loss: 11, 13, 18, Y
Gain: 12p*, 7, 8, X
Gain: 9
the primary imaging modality used for
tumour staging.
Tumour markers
There are two principal serum tumour
markers, alpha fetoprotein (AFP) and the
beta subunit of human chorionic gonadotropin
(ßhCG). The former is seen in
patients with yolk sac tumours and teratomas,
while the latter may be seen in
any patients whose tumours include syncytiotrophoblastic
cells.
AFP is normally synthesized by fetal yolk
sac and also the liver and intestine. It is
elevated in 50-70% of testicular germ
cell tumours and has a serum half life of
4.5 days {305,1333}.
hCG is secreted by placental trophoblastic
cells. There are two subunits, alpha
and beta, but it is the beta subunit with a
half life of 24-36 hours that is elevated in
50% of patients with germ cell tumours.
Patients with seminoma may have an elevation
of this tumour marker in 10-25% of
cases, and all those with choriocarcinoma
have elevated ßhCG {1333}.
If postorchiectomy levels do not decline
as predicted by their half lives to appropriate
levels residual disease should be
suspected. Also a normal level of each
marker does not necessarily imply the
absence of disease.
Lactate dehydrogenase (LDH) may also
be elevated, and there is a direct relationship
between LDH and tumour burden.
However, this test is nonspecific
although its degree of elevation correlates
with bulk of disease.
Tumour spread and staging
The lymphatic vessels from the right testis
drain into lymph nodes lateral, anterior,
and medial to the vena cava. The left
testis drains into lymph nodes distal, lateral
and anterior to the aorta, above the
level of the inferior mesenteric artery.
These retroperitoneal nodes drain from
the thoracic duct into the left supraclavicular
lymph nodes and the subclavian vein.
Somatic genetics
Epidemiology, clinical behaviour, histology,
and chromosomal constitution
define three entities of germ cell tumours
(GCTs) in the testis {1540,1541,1965}:
teratomas and yolk sac tumours of
neonates and infants, seminomas and
non-seminomas of adolescents and
young adults, the so called TGCTs, and
the spermatocytic seminomas of elderly.
Germ cell tumours
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