Diagnostic Ultrasound - Abdomen and Pelvis

Tubular Ectasia of Rete Testis
Diagnoses: Scrotum
TERMINOLOGY
• Dilated rete testis
• Cystic transformation of rete testis
IMAGING
• Frequently bilateral
○ Usually asymmetric involvement
• Branching tubules converging at mediastinum testis
○ Dilated tubules create lace-like or "fishnet" appearance
• Adjacent parenchyma is normal
• Associated ipsilateral spermatoceles are common
• Tubules are avascular and fluid filled
○ No flow on color Doppler imaging
• MR performed for confirmation if cystic malignant
neoplasm cannot be ruled out
TOP DIFFERENTIAL DIAGNOSES
• Testicular carcinoma
KEY FACTS
○ Mixed germ cell tumors with teratomatous components
will often have cystic areas
○ Does not form network of tubules
• Intratesticular varicocele
○ Characteristic color flow on Doppler
• Testicular infarct
○ Avascular wedge-shaped area with sharp borders
CLINICAL ISSUES
• Generally nonpalpable and asymptomatic
• May be found when doing ultrasound for related issue,
such as epididymal cyst
DIAGNOSTIC CHECKLIST
• Important to distinguish tubular ectasia from malignancy to
prevent unnecessary orchiectomy
(Left) Transverse grayscale
ultrasound of the testes
demonstrates bilateral tubular
ectasia of the rete testis,
which is slightly asymmetric,
right greater than left .
(Right) Sagittal grayscale
ultrasound of the left testis
demonstrates cystic areas
within the mediastinum testis,
consistent with tubular ectasia
of the rete testis.
(Left) Transverse color
Doppler ultrasound of the
right testicle demonstrates
avascular cystic areas within
the testis with a cystic area
within the epididymal head
. These findings are
consistent with tubular ectasia
of the rete testis with
associated spermatocele.
(Right) Sagittal grayscale
ultrasound of the epididymal
head demonstrates large
spermatoceles with
partially visualized tubular
ectasia .
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