Hydroureter

Hydroureter refers to abnormal dilation (>3 mm) of the ureter and may occur in combination with hydronephrosis. 

Terminology

The term, megaureter, is usually reserved for ureters >7 mm in diameter. The term hydroureteronephrosis (or hydronephroureterosis) may be used when ureteric dilatation occurs in the presence of hydronephrosis. 

Clinical presentation

Clinical presentation is variable but may include:

• flank pain
• nausea, vomiting

Pathology

Etiology

Hydroureter is a non-specific finding. Etiologies include:

• acquired
  • obstructed
    • intraluminal
      • ureterolithiasis
      • clots
      • sloughed papillae from renal papillary necrosis (often associated with analgesic abuse)
    • intramural
      • malignancy
      • stricture
      • inflammatory
        • malacoplakia
    • extrinsic
      • crossing vessels
      • mass effect
  • unobstructed
    • polyuria
    • residual dilation from a prior obstruction that has recently resolved (e.g. passed urolithiasis)
    • urinary tract infection ²
    • chronic reflux from a uroenteric diversion
• congenital
  • vesicoureteral reflux
  • primary megaureter
  • ureterocele
  • prune belly syndrome
  • ectopic ureter

Radiographic features

A ureteral diameter of >3 mm has been described as the cut-off for hydroureter ^1,3.

History and etymology

From the Latin "hydro", meaning of water.