Scrotum and Testes Part 3

Learning Objectives

Identify and describe common pathologies on sonographic images of the scrotum and testes
Differentiate the aetiology, clinical presentations, and sonographic appearances of:
- Hydrocele
- Epididymal cyst
- Varicocele
- Epididymitis
- Epididymo-orchitis
- Cryptorchidism
- Scrotal pearl
- Microlithiasis
- Germ cell tumours

Common Pathologies for Scrotum and Testes

Clinical Indicators

Extratesticular lumps or swelling:
- Hydrocele
- Epididymal cyst
- Varicocele
- Epididymitis, orchitis, or epididymo-orchitis
- Cryptorchidism
- Scrotal pearl
- Microlithiasis
Intratesticular lumps or swelling
Scrotal swelling with pain (discussed in part 4 in lecture series)

Extratesticular Lumps or Swelling

Hydrocele: A serous fluid collection between layers of the tunica vaginalis surrounding the testis or spermatic cord.
- Types: Acquired or congenital
- Causes of acquired hydroceles: Trauma, epididymitis, testicular torsion, neoplasm, and infarction.
- Clinical Presentation: Usually a painless scrotal swelling; can become painful if infected (pyocele).
- Ultrasound Appearance: Testicular
- Simple avascular fluid collection around the testis, may extend to the inguinal canal
- Low-level echoes possible due to protein aggregation or cholesterol crystals.
- Ultrasound Appearance: spermatic cord
- Anaechoic mass in the groin along the spermatic cord
- Situated above and separate from the testis and epididymus
- Avascular
Epididymal Cyst:
- Most common epididymal mass, usually contains lymphatic fluid, can be single or multiple.
- Clinical Presentation: Often a palpable mass, asymptomatic in one-third of patients.
- Ultrasound Appearance:
- Well-defined anechoic lesion within the epididymis
- Shows posterior acoustic enhancement.
- Large cysts can displace the testis
Spermatocele: benign cystic lesions that contain spermatozoa, lymphocytes and debris
- Cause: forms as a result of efferent duct obstruction and usually located at the head of epididymus
- Cannot be differentiated from epididymal cysts apart from spermatoceles usually having septations
- Can be associated with a prior vasectomy
- Clinical presentation: usually a painless incidental finding; can present as a mass lesion if large enough
- Ultrasound apperance: well defined epididymal cystic lesions with posterior enhancement; low-level echoes representing spermatozoa; septations; can still be anaechoic and singular; indistinguishable from an epidiymal cyst
Varicocele: Dilatation of the pampiniform plexus of veins within the spermatic cord and the most common mass of the spermatic cord. Most common cause of male infertility
- Causes: most are primary resulting from incompetent or congenitally absent valves in the testicular vein.
- Secondary varicoleles less common and reuslt from increased pressure in testicular vein due to compression from renal enal mass, lymphadenopathy or renal vein compression in nutcracker syndrome
- Left testicles more affected than the right due to the anatomical differences in venous drainage, leading to a higher incidence of varicocele on the left side.
- Clinical Presentation: Can be asymptomatic; symptoms may include scrotal mass/swelling, pain, testicular atrophy, and infertility.
- Ultrasound Appearance:
- Dilated veins >2-3 mm in diameter
- Scrotal mass with a "Bag of worms" appearance above or posterior to the testes
- Veins increase in size with Valsalva maneuver.
Epididymitis and Epididymo-orchitis:
- Infection that originates in bladder/prostate and spreads via ductus deferens → lymphatics → spermatic cord —> epididymis → testis
- Tail of epididmysis affected first - epididymitis
- If nfection then moves to head of epididymis then testis - epidiyomo-orchitis
- Clinical Presentation: Range from mild tenderness to acute scrotal pain; fever, warmth, and swelling in the scrotum can occur.
- Ultrasound Appearance:
- Thickened, hypoechoic epididymis with increased blood flow; reactive hydrocele may be present.
- Epididymo-orchits - testes have increased blood flow which can be large and heterogenous
Cryptorchidism: Absence of testis in scrotal sac, due to undescended or ectopic testis.
- Causes: Premature birth, IUGR, maternal lifestyle during pregnancy (smoking, alcohol).
- Clinical presentation: one testis or both missing from scrotal sac
- Ultrasound Appearance:
- Lack of testis in scrotal sac; undescended testis appears homogenous and hypoechoic.
Scrotal Pearl: Benign macrocalcifications in scrotum, occur due to microtrauma.
- Clinical Presentation: Usually asymptomatic; diagnosed incidentally.
- Ultrasound Appearance:
- Small mobile hyperechoic extratesticular focus within the tunica space; pearl may show posterior acoustic shadowing if large; can appear as free floating if there is a hydrocele
Microlithiasis: Tiny calcium deposits within testes associated with increased risk of testicular cancer.
- Clinical Presentation: Usually asymptomatic.
- Ultrasound Appearance:
- Small non-shadowing hyperechoic foci ranging in diamter from 2-3mm , uniform in size or clustered but can be seen peripherally or segmentally

Intratesticular Lumps

Germ Cell Tumours:
- Most common type of testicular cancer (includes seminoma and non-seminoma).
- Seminomas: Most common in males aged 15-49 years; associated with undescended testes.
- Risk Factors: undescended tests; family history of germ cell tumour, microlithiasis, infections such as HIV, mumps, orchitis
- Clinical Presentation: Painless testicular mass; other symptoms may include discomfort or back pain.
- Ultrasound Appearance: Homogeneous intratesticular mass, well-circumscribed with lobulated margins, internal vascularity
- Non-seminomas: Occur mainly in younger patients, more aggressive, and metastasize frequently.
- Clinical Presentation: Similar to seminomas with potential for metastasis.
- Ultrasound Appearance: More heterogeneous with cystic areas or calcification.