Tubular
Ectasia of Rete Testis
TERMINOLOGY
•
Dilated rete testis
•
Cystic transformation of rete testis
Best diagnostic clue
○
Variably sized network of dilated tubules near mediastinum testis with no flow
on color Doppler
Location
○
Posterior near mediastinum testis
○
Frequently bilateral
Size
○
Can replace large portion of normal parenchyma
○
Variably sized cystic spaces
Morphology
○
Branching tubules converging at mediastinum testis
○
Characteristic appearance and location make it possible to distinguish this
benign condition from malignancy
Ultrasonographic Findings
•
Grayscale ultrasound
○
Longitudinal plane shows branching tubular structures along mediastinum
○
Dilated tubules create lace-like or "fishnet" appearance
○
Adjacent parenchyma is normal
. it Differentiates it from cystic malignant masses, which have
abnormal rind of parenchyma
○
Associated ipsilateral spermatoceles are common. May also see intratesticular
cysts
Color Doppler
○
Tubules are avascular and fluid filled, hence no color flow
○
Normal flow in adjacent testicular parenchyma
MR Findings
•
MR performed for confirmation if cystic malignant neoplasm cannot be ruled out
•
T1 and proton density-weighted Images: Hypointense to testis
•
T2WI: Iso- to hyperintense to testis → nearly invisible
○
Malignant testicular neoplasms → solid portions hypointense on T2WI; have dark
fibrous capsule
• Best imaging tool
○
High-resolution US (≥ 7.5 MHz) is imaging modality of
choice
• Protocol advice
○
Longitudinal plane shows morphology of tubules far better than transverse plane.
It Appears more mass-like and has greater
likelihood of causing confusion when viewed in transverse plane
○
Always use color Doppler to look for areas of abnormal parenchymal flow
PATHOLOGY
• Etiology
○
Partial or complete efferent ductule obstruction → ectasia → eventually cystic
transformation
○
May be associated with epididymal obstruction due to inflammation or trauma
• Associated abnormalities
○
Spermatocele
○
Epididymal cyst
○
Intratesticular cyst
CLINICAL ISSUES
Presentation
○
Generally nonpalpable and asymptomatic
○
May be found when doing ultrasound for related issue, such as epididymal cyst
or spermatocele
Age
○
Middle-aged to elderly men most commonly affected
DIAGNOSTIC CHECKLIST
•
Important to distinguish tubular ectasia from malignancy to prevent unnecessary
orchiectomy
Imaging Gallery
 |
grayscale ultrasound of the testes demonstrates bilateral tubular ectasia of the rete testis, which is slightly asymmetric, right greater than left
 |
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.
|
 |
grayscale ultrasound of the left testis demonstrates cystic areas within the mediastinum testis, consistent with tubular ectasia of the rete testis.
|
 |
| grayscale ultrasound of the epididymal head demonstrates large spermatoceles with partially visualized tubular ectasia . |