A collection of fluid between the parietal and visceral layers of the tunica vaginalis within the scrotum

  • Communicating hydrocele (patent processus vaginalis)
    • Direct communication with the peritoneal cavity
    • Contains peritoneal fluid
    • Almost always with associated indirect inguinal hernia
    • Decreases in size with recumbent position
  • Noncommunicating hydrocele (The processus vaginalis is not patent.)
    • No direct connection to the peritoneal cavity
    • Fluid contained is from the mesothelial lining.
    • Can be isolated to the cord with the distal and proximal portions of the processus vaginalis closed
  • Acute hydrocele: fluid collection resulting from an acute process within the tunica vaginalis, typically involving only the scrotum
  • Although this disorder is found nearly exclusively in male patients, there is a rare hydrocele into the canal of Nuck in females which results from a fluid collection in an abnormal open pouch of peritoneum extending into the labia majora.
  • System(s) affected: urogenital

Pediatric Considerations
Most congenital communicating hydroceles resolve spontaneously by 2 years of age.


Predominant age: childhood

Estimated at 0.7–4.7% of male infants


  • 1,000/100,000
  • Estimated at 1% of adult men

Etiology and Pathophysiology

  • Incomplete closure of the processus vaginalis trapping peritoneal fluid anywhere along the length of the tunica vaginalis
  • Failure of closure of the processus vaginalis maintaining a communication to the peritoneal cavity
  • Imbalance of the secretion and reabsorption of fluid from the lining of the tunica vaginalis
  • Infection
  • Tumors
  • Trauma
  • Ipsilateral renal transplantation (due to disruption of the spermatic cord during the procedure)

Risk Factors

  • For adult-acquired hydroceles:
    • Ventriculoperitoneal shunt
    • Ehlers-Danlos syndrome
    • Peritoneal dialysis
    • History of scrotal surgery to include varicocelectomy
  • For congenital hydroceles:
    • Exstrophy of the bladder
    • Cloacal exstrophy

Commonly Associated Conditions

  • For adult-acquired hydroceles:
    • Testicular tumors
    • Scrotal trauma
    • Ventriculoperitoneal shunt
    • Nephrotic syndrome
    • Renal failure with peritoneal dialysis

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