Diagnostic Ultrasound - Abdomen and Pelvis

Hydrocele
TERMINOLOGY
Definitions
• Congenital or acquired serous fluid contained within layers
of scrotal tunica vaginalis
IMAGING
General Features
• Best diagnostic clue
○ Scrotal fluid surrounding testis, except for "bare area"
where tunica vaginalis does not cover testis and is
attached to epididymis
• Location
○ Intrascrotal, external to testis and epididymis
○ Not within scrotal wall
○ Specific anatomic location: Tunica vaginalis
• Morphology
○ Simple or complex avascular fluid
Ultrasonographic Findings
• Grayscale ultrasound
○ Acute hydrocele (AH): Crescentic anechoic fluid
collection surrounding anterolateral aspect of testis
– Usually testis displaced posteromedially
○ Chronic hydrocele (CH): Low-level, mobile echoes
– Cholesterol crystals presumed to cause these lowlevel
mobile echoes and cannot be distinguished from
inflammatory debris; beware of artifacts on color
Doppler
– Diffuse scrotal wall thickening, parietal calcifications
and scrotoliths
– Septations may be present, should be avascular
• Power Doppler
○ May demonstrate movement of internal debris in
chronic hydrocele
MR Findings
• T1WI
○ Low signal intrascrotal collection with no enhancement
• T2WI
○ Homogeneous high signal collection when fluid is simple,
may be intermediate when chronic or complex
Imaging Recommendations
• High-resolution US (9-15 MHz) is modality of choice
DIFFERENTIAL DIAGNOSIS
Pyocele
• Septated fluid with low-level internal echoes
• Associated with epididymitis, intrascrotal abscess, and
clinical signs of inflammation
Hematocele
• Complex echogenic fluid in tunica vaginalis on US
• Associated with trauma, torsion, and infarct
Scrotal Hernia
• Peristalsing bowel or echogenic omentum within scrotum
PATHOLOGY
General Features
• Etiology
○ Embryology-anatomy
– Congenital or communicating hydrocele is due to
failure of processus vaginalis to close
– Secondary occurrence in adults due to epididymitis,
trauma, surgery, or tumor
• Simple fluid collection within tunica vaginalis
• Chronic cases show thickened tunica with septation
○ Complex fluid may be seen in acute infection or
afterwards
○ Scrotal hematoma may be slow to resolve and manifest
as complex collection
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Asymptomatic (painless) scrotal mass/enlargement
Demographics
• Epidemiology
○ Congenital hydroceles usually resolve by 18 months of
age
○ 25-50% of acquired hydroceles are associated with
trauma
○ 10% of testicular tumors have associated hydrocele
Treatment
• Surgical hydrocelectomy: Open drainage of fluid and
oversewing of hydrocele sac edges
• Aspiration and sclerotherapy: Less invasive approach with
slightly higher risk of recurrence
DIAGNOSTIC CHECKLIST
Image Interpretation Pearls
• Anechoic fluid collection in tunica vaginalis along
anterolateral aspect of testis
SELECTED REFERENCES
1. Rafailidis V et al: Sonography of the scrotum: from appendages to
scrotolithiasis. J Ultrasound Med. 34(3):507-18, 2015
2. Koutsoumis G et al: Primary new-onset hydroceles presenting in late
childhood and pre-adolescent patients resemble the adult type hydrocele
pathology. J Pediatr Surg. 49(11):1656-8, 2014
3. Shakiba B et al: Aspiration and sclerotherapy versus hydrocoelectomy for
treating hydrocoeles. Cochrane Database Syst Rev. 11:CD009735, 2014
4. Naji H et al: Decision making in the management of hydroceles in infants and
children. Eur J Pediatr. 171(5):807-10, 2012
5. Rizvi SA et al: Role of color Doppler ultrasonography in evaluation of scrotal
swellings: pattern of disease in 120 patients with review of literature. Urol J.
8(1):60-5, 2011
6. Garriga V et al: US of the tunica vaginalis testis: anatomic relationships and
pathologic conditions. Radiographics. 29(7):2017-32, 2009
7. Woodward PJ et al: From the archives of the AFIP: extratesticular scrotal
masses: radiologic-pathologic correlation. Radiographics. 23(1):215-40, 2003
Diagnoses: Scrotum
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