Scrotal masses

• Testis

• Epididymis

• Spermatic cord

• Their fascial coverings

• The first imaging procedure to evaluate the

scrotum.

• The study has to be performed with high frequency

transducers (>10 MHz) with color Doppler facilities.

• MRI can be useful in the evaluation of scrotal

masses as a problem-solving technique:

1. Discrepancies between US and clinical

findings.

2. Diffuse, non-specific testicular involvement

seen on US scanning.

3. Fibrous lesions, lipomas or hemorrhage are

suspected.

• Testis.

• Tunica albuginea.

• The mediastinum testis.

• The epididymis.

• Most solid lesions originating from the testes are

malignant, while most lesions originating from

extratesticular structures are benign

• The most common extratesticular neoplasms are benign

lipomas, usually originating from the spermatic cord,

and adenomatoid tumors, most often from the

epididymis.

• In patients with a scrotal mass, imaging is requested to

answer the following five questions:

1. Is there a definite mass?

2. Is the mass intra- or extratesticular?

3. Is the mass bilateral?

4. Is the mass cystic or solid?

5. Is the nature of the lesion identifiable?

1. Is there a definite mass?

• US is almost 100% sensitive in the identification of

presence of scrotal masses.

• Diagnostic difficulties leading to false-negative results

are rarely encountered, and are mostly due to:

o Presence of isoechogenic intratesticular lesions

o Diffuse testicular involvement, especially in children

with yolk-sac tumors

o Extratesticular lipomas can be difficult to identify,

being often isoechoic to surrounding subcutaneous

tissue.

2. Is the mass intra- or extratesticular?

• Differentiation can be made by US in almost all

cases.

• Palpation during US examination can help to localize

the mass.

3. Is the mass bilateral?

• Testicular tumors can be bilateral (38% of

lymphomas, 2% of seminomas).

4. Is the lesion cystic or solid?

• US can easily differentiate a solid from a cystic

lesion.

• A lesion may be defined as a ‘cyst’ only if it is

completely anechoic, with increased through

transmission and presence of thin walls, without

any vegetations or irregularities.

5. Is the nature of the lesion identifiable?

• Identification of the nature of scrotal masses

cannot be based on imaging methods alone.

• Localization of the mass is important in predicting

the nature of the lesion.

o Most extratesticular lesions are benign

o Most intratesticular masses are malignant.

• The structural pattern of the mass is the second

important factor to consider.

o Most cystic lesions are benign, while solid

nodules are more often malignant.

Testicular Tumors

Age:

• First Decade → Yolk Sac Tumors – Teratomas.

• Second & Third Decade → Teratoma & Choriocarcinoma.

• Forth And Fifth Decade → Seminoma.

Testicular Tumors

Tumors Markers:

• Alpha Fetoprotein → All Yolk Sac Tumors – 75% Of

Embryonal Carcinoma.

• Human Chorionic Gonadotrophin (hCG) → All

Choriocarcinoma - 60% Embryonal Carcinoma.

• A common benign lesion (retention cyst).

• It is a cyst filled with cheesy laminated material

that appears solid on imaging.

• A rare benign tumor (approximately 1% of all

testicular tumors).

• It is a cyst filled with cheesy laminated material

that appears solid on imaging.

• At US, the lesion is seen as rounded or oval shaped nodule

with regular outer margins.

• The lesion tends to be hyperechoic, sometimes calcific outer

wall is seen, and an internal ’onion ring’ structure is

characteristic of an epidermoid cyst. No vascular signals are

seen at Doppler evaluation

• At MRI, a laminated appearance, with alternate low-and high-

signal intensity areas can be detected on T2-weighted images.

• US: Seminomas are well

defined and homogeneously

hypoechoic

• On MRI, Homogeneously hypointense on T2-weighted images.

Larger tumors may be more heterogeneous

• Non-seminomatous lesions are more heterogenous with areas of

hemorrhage and calcification.

• The tunica albuginea may be invaded.

• US findings are usually sufficient to suggest the diagnosis. The

testis is typically replaced by infiltrative hypoechoic

hypervascular lymphoid tissue.

• MR imaging findings are similar, with the testis being replaced

by tissue that is low signal intensity on T1- and T2-weighted

images, with low-level enhancement (less than the normal testis)

• “Burned-out" Germ Cell Tumor

• Extra-Testicular pseudo-tumors

• Testicular pseudo-tumors