In the diagnosis and staging of testicular tumor, imaging studies
are of primary importance. Although most tumors are diagnosed
based on physical examination findings, scrotal ultrasound is
typically performed to ensure the correct diagnosis or to establish
a diagnosis in a patient in whom the testicular examination cannot
differentiate the scrotal structures.
Testicular tumors occur most frequently in the 20 to 40 year age
group and make up 1 to 2 % of all cancers in males and 1.5 pet
cent of all childhood malignancies. Their incidence is increased
5 to 100 times in undescended testicles.
15 % of testicular tumors present with a hydrocoele whilst others
present with a testicular mass or distant metastases. 10 % of
patients present with acute pain due to intratesticular hemorrhage.
Metastases may be present at présentation in 4 to 14 % of patients
to lung, liver, bones, brain and lymph nodes.
Classification of Testicular Neoplasms
Germ cell tumors
--Mixed germ cell
--Leydig cell tumor
--Sertoli cell tumor
An intratesticular mass is malignant until
Sonography is highly sensitive in detecting
testicular tumors : 95% to 100%. Determination by the sonographer
of whether the mass is intratesticular or extratesticular in location
is important. Scrotal sonography approaches 100 % accuracy in
distinguishing an intratesticular mass from an extratesticular
mass. In addition, sonography is extremely accurate in determination
of the exact location of a scrotal mass, but it is less accurate
in distinguishing whether an intratesticular mass is malignant
Over 90 % of testicular neoplasms are completely or predominantly
hypoechoic. Infarction and inflammation may also give rise to
focal hypoechoic areas and thus a hypoechoic focus does not necessarily
High-frequency sonography is a very accurate means of demonstrating
testicular parenchyma and a normal scan is almost 100 % accurate
at excluding testicular malignancy. Color Doppler sonography show
little vascularity in tumors less than 1.5 cm in size but tumors
larger than 1.6cm consistently display hypervascularity and distortion
of blood vessels.
There are numerous lesions that can simulate testis tumors. These
* focal orchitis.
* focal fibrosis.
* adrenal rest tissue.
In many cases the patient's history is useful in suggesting the
One relatively common abnormality that is easy to mistake for
a tumor is testicular atrophy and fibrosis. In most patients these
conditions can produce hypoechoic regions in the testis that are
arranged in a linear pattern, producing a striated appearance
to the testis that does not simulate a tumor. However, if these
areas become more confluent, they can be misdiagnosed as tumors.
This mistake can usually be avoided by scanning in multiple planes
and noting the wedge shape or the abnormality and the way it radiates
from the mediastinum.
This tumor accounts for 50 % of primary testicular neoplasm and
is the most common tumor in the undescended testis. The age group
affected is between 30 and 40 years. The tumors may be multifocal.
A quarter already show metastases at presentation usually to the
lungs. Tumor activity can be monitored by beta-human chorionic
gonadotrophin which is elevated in 10 to 15 % of patients. The
serum alpha in is usually normal.
Ultrasound appearances : Seminomas
present as a solid, hypoechoic mass that is homogeneous, although
occasionally scattered echogenic areas may be identified. Seminomas
are usually unilateral and may be very small in size : 2 to 3
mm. Seminomas may also almost completely replace normal testicular
Embryonal cell tumor
It is the second most common type of testicular neoplasm and accounts
for 25% of primary testicular neoplasms. They usually affect patients
in their second and third decades and children under the age of
2 years. These tumors are the most aggressive testicular neoplasms
that predispose to visceral metastases.
The commonest ultrasound appearance
is that of a hypoechoic mass with irregular borders, that may
show echogenic foci because of areas of calcification and cystic
areas because of hemorrhage and necrosis. These tumors are aggressive
and may distort the normal contour of the testicle when invasion
of the tunica albuginea occurs.
Teratomas account for 5% to 10% of scrotal tumors and are generally
seen in men between 25 and 35 years of age. The tumor may be benign
in children but may transform into malignancy.
Sonographic Findings : Teratomas
may contain hair, bone, and teeth. Teratomas are usually well
differentiated and, depending on which tissue components they
contain, may be hyperechoic, hypoechoic, or complex and demonstrate
The incidence of this tumor is 1 to 3 % with a peak age incidence
of 20 to 30 years. The prognosis is poor and is rapidly fatal.
Ultrasound appearances : Choriocarcinomas
usually present as a small mass with mixed echogenicity from hemorrhage,
necrosis, and calcifications.
Yolk sac tumor
This is a rare tumor which is considered equivalent to the endodermal
sinus tumor of the ovary. Yolk cell tumor elements are said to
be present in 38 % of other adult germ cell tumors except a seminoma.
The tumor primarily affects children under 3 years of age. The
tumors frequently metastasise to the lung. Specific ultrasound
appearances have not been described.
Non-Hodgkin's, especially B-cell lymphoma, represents the most
common secondary neoplasm of the testis and the most common testicular
malignancy in men over the age of 60 years. Sonographic
Findings :Testicular lymphoma may appear hypoechoic and
enlarged with anechoic masses. Lymphoma usually presents as a
diffuse mass but occasionally may be focal.. The tumor may extend
into the epididymis and spermatic cord but invasion of the tunica
albuginea is usually rare.
Sonography reveals diffuse or focal
nodular decreased echogenicity with preservation of the ovoid
testicular shape. Doppler ultrasound shows a strikingly increased
vascular flow unrelated to the size or extent of the tumor, unlike
that with primary testicular tumors.
In adults the common primary sites that metastasise to the testis
include the prostate, lungs, kidneys, gastrointestinal tract,
bladder, thyroid and melanoma. In children neuroblastoma and Wilms'
tumor is often implicated.
Sonographic Findings : metastases
are often hypoechoic but echogenic masses may occur. The sonographic
findings may be indistinguishable from lymphomas or primary testicular
These testicular tumors, which arise from the Sertoli cells of
the seminiferous tubules, are associated with hormonal abnormalities
such as gynaecomastia and precocious puberty. Over 90 % of these
tumors are benign and usually arise in the first year of life.
sonographic appearances : These testicular
tumors are those of a smooth rounded area, 5 to 10 mm in size,
with curvilinear calcification. Calcification within the testis
without an associated soft tissue mass is strongly suggestive
of this tumor. Doppler ultrasound may display increased blood
flow within or adjacent to the lesion.
Leydig's Cell Tumors Leydig's
cell tumors are also called interstitial cell tumors and arise
from the interstitial cells that form the fibrovascular stroma
of the testis. These tumors account for 1% to 3% of testicular
neoplasms. They are usually considered benign, but 10% of these
tumors are malignant. As with Sertoli cell tumors they may be
hormone secreting, which may be feminizing or result in precocious
The ultrasonic appearances are those
of a hypoechoic mass. They may contain focal areas of hemorrhage
and necrosis within the tumor, creating cystic areas identified
in 25% of Leydig's cell tumors.
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