What is a hydrocele?

What is a Hydrocele?

A hydrocele is an abnormal collection of serous fluid between the parietal and visceral layers of the tunica vaginalis that surrounds the testis and spermatic cord. 1

Pathophysiology

• Hydroceles result from an imbalance between fluid secretion and reabsorption by the mesothelial lining of the tunica vaginalis 1
• The fluid accumulates in the potential space between the two layers of the tunica vaginalis that normally surrounds the testis 2

Classification

Hydroceles are divided into two main types: 1, 3

Primary Hydroceles

• Neonatal/congenital: Present at birth
• Communicating: Connected to the peritoneal cavity through a patent processus vaginalis
• Non-communicating (closed/adult type): Isolated fluid collection without connection to the peritoneal cavity 4

Secondary Hydroceles

• Develop as a reactive process to underlying conditions such as:
  • Infection/inflammation (epididymitis, orchitis)
  • Trauma
  • Tumors (rarely) 1, 3
  • Post-surgical (particularly after varicocelectomy) 2

Clinical Presentation

• Painless scrotal swelling is the most common presentation 2, 5
• The swelling typically transilluminates on physical examination 6
• May cause discomfort or psychosocial distress depending on size 3
• Important caveat: Any fluctuation in size suggests a patent processus vaginalis (communicating hydrocele) and requires different management 2

Diagnostic Approach

• Physical examination with transillumination is usually sufficient for diagnosis 2, 6
• Scrotal ultrasonography is mandatory when the testis is non-palpable to rule out underlying testicular masses 2
• Warning: In young men, what appears as a "complex hydrocele" on ultrasound may actually represent an underlying testicular tumor—maintain high clinical suspicion 5
• Ultrasound findings show an anechoic (fluid-filled) collection around the testis 7

Clinical Context in Acute Scrotum

• Hydrocele can be a reactive finding in acute scrotal conditions, particularly epididymitis where it develops as inflammation and edema progress 8
• In testicular torsion, an ipsilateral hydrocele may be present along with other findings such as enlarged heterogeneous testis and skin thickening 8