Diagnostic Ultrasound - Abdomen and Pelvis

Extratesticular Cystic Mass
Differential Diagnoses: Scrotum
DIFFERENTIAL DIAGNOSIS
Common
• Hydrocele
• Varicocele
• Spermatocele
• Epididymal Cyst
Less Common
• Tunica Albuginea Cyst
• Acute Hematocele
• Pyocele
• Epididymal or Scrotal Wall Abscess
• Inguinal Hernia Containing Bowel
Rare but Important
• Papillary Cystadenoma of Epididymis
ESSENTIAL INFORMATION
Helpful Clues for Common Diagnoses
• Hydrocele
○ Congenital or acquired
○ Fluid collection in tunica vaginalis
– May be simple or complex
○ Envelops testis except for "bare area" where tunica
vaginalis is deficient
• Varicocele
○ Dilation of veins of pampiniform plexus > 3 mm, due to
retrograde flow in internal spermatic vein
○ Enlargement and "color flash" with Valsalva maneuver
○ Left (78%), right (6%), bilateral (16%)
• Spermatocele
○ Retention cyst of tubules connecting rete testis to head
of epididymis
○ Located in head of epididymis; contains spermatozoa
○ Often associated with tubular ectasia of rete testis
• Epididymal Cyst
○ Simple cyst in epididymal head, body, tail
○ Anechoic, does not contain spermatozoa
Helpful Clues for Less Common Diagnoses
• Tunica Albuginea Cyst
○ Invested between layers of tunica albuginea
– May appear as intra-/extratesticular cyst
○ Usually solitary but can be multiple
– 2-3 mm diameter
○ Asymptomatic
• Acute Hematocele
○ Associated with trauma, torsion, and infarction
○ Varies in appearance with evolution of blood products
○ Look for associated testicular injury
• Pyocele
○ Sequela of scrotal infections
○ Septate fluid with low-level internal echoes
○ Chronicity may lead to thickening of tunica and scrotal
wall
• Epididymal or Scrotal Wall Abscess
○ Associated with chronic epididymitis or orchitis
○ No central vascularity but surrounding hyperemia
○ Internal contents complex, rarely simple
• Inguinal Hernia Containing Bowel
○ Varies with Valsalva
○ Multilaminar gut signature present
○ May show peristalsis
Helpful Clues for Rare Diagnoses
• Papillary Cystadenoma of Epididymis
○ Rare benign lesion associated with von Hippel-Lindau
syndrome
○ Cystic and solid epididymal mass
SELECTED REFERENCES
1. Mirochnik B et al: Ultrasound evaluation of scrotal pathology. Radiol Clin
North Am. 50(2):317-32, vi, 2012
2. Wasnik AP et al: Scrotal pearls and pitfalls: ultrasound findings of benign
scrotal lesions. Ultrasound Q. 28(4):281-91, 2012
3. Valentino M et al: Cystic lesions and scrotal fluid collections in adults:
Ultrasound findings. J Ultrasound. 14(4):208-15, 2011
(Left) Longitudinal ultrasound
of scrotum shows anechoic
fluid within the tunica
vaginalis, indicative of a
simple hydrocele. Fluid in the
tunica vaginalis envelops the
testis except posteriorly st at
the "bare area." (Right) Wellcircumscribed
cystic collection
st superior to the right testis
contains punctate echogenic
spermatozoa and debris,
which is mobile and generates
Doppler artifact in real
time.
Hydrocele
Spermatocele
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