Epidemiology

• Clinically apparent scrotal hydroceles are evident in 6% of term males beyond the newborn period.
• Most paediatric hydroceles are congenital, but rarer causes include malignancy and infection.
• Hydroceles presenting in older boys and men may be secondary to epididymo-orchitis, tuberculosis, torsion, testicular tumours, trauma, associated with generalised oedema (eg, nephrotic syndrome or heart failure), or following renal transplantation or post-radiation therapy.^[4]
• Rarely, similar fluid collections can develop along the canal of Nuck in females.^[3]

Presentation

• Scrotal enlargement with a non-tender, cystic swelling.
• Pain is not a feature unless the hydrocele is infected or if there is pain from an underlying cause.
• The testis is usually palpable but may be difficult to palpate if the hydrocele is large.
• A hydrocele lies anterior to and below the testis and will transilluminate. Transillumination is not diagnostic and does not rule out a more urgent scrotal problem.^[4]

Differential diagnosis

Differentiating between a hydrocele and an acute scrotal problem such as testicular torsion or strangulated hernia is very important.^[4] See separate article Lumps in the Groin and Scrotum.

Investigations

Investigations are not required for simple hydroceles but are essential if there is any doubt in the diagnosis or any suggestion of an underlying cause. Failure to clearly delineate the testis, tenderness on palpation or internal shadows on transillumination are all indications for further investigation:

• Ultrasound can help to determine if any underlying pathology is present. Spermatoceles can be clearly distinguished.
• Duplex sonography may provide information about testicular blood flow when a hydrocele may be associated with chronic torsion of the testis.^[3]
• Diagnostic aspirations should be avoided, as they may lead to the spread of malignant cells.
• Serum alpha-fetoprotein and human chorionic gonadotrophin levels help to exclude malignant teratomas or other germ cell tumours.

Management

• Many hydroceles in infancy resolve before the age of 2 years and so observation and non-intervention are usually appropriate for hydroceles in infants. Early surgery in this age group is indicated if there is suspicion of an associated inguinal hernia or underlying testicular pathology.^[5]
• Once underlying pathology has been excluded, adults with non-communicating hydroceles can be managed conservatively, with reassurance and a scrotal support.
• Therapeutic aspiration may be required for large hydroceles. However, aspiration is otherwise not recommended unless for symptomatic relief in an elderly man who is unfit for surgery.^[1]
• An exploratory operation is required if the diagnosis is uncertain or underlying pathology cannot be excluded. Other indications for operation are if the hydrocele is large and uncomfortable, if it becomes infected or if it repeatedly re-accumulates after aspiration.

Surgical removal

Surgical removal of a hydrocele can be performed by one of the following:^[3]

• Inguinal approach with ligation of the processus vaginalis high within the internal inguinal ring:
  • This is the procedure of choice for paediatric communicating hydroceles.
  • An inguinal approach is essential if a testicular tumour has been identified pre-operatively, or is a possibility.
  • It has been recommended that children younger than 12 years should undergo inguinal exploration for hydrocele repair.^[6]
• Scrotal approach with excision or eversion and suturing of the tunica vaginalis:
  • This is recommended for chronic non-communicating hydroceles.
  • It is possible in children older than 12 years to repair hydroceles through a scrotal incision, unless the clinical history is suggestive of a communication.^[6]
• Scrotal aspiration and sclerotherapy of the hemiscrotum, using tetracycline or doxycycline solutions:^[4]
  • Recurrence after sclerotherapy, pain and epididymal obstruction are common.
  • Therefore, this procedure is mainly indicated for poor surgical candidates with symptomatic hydroceles and when fertility is not an issue.
  • Sclerosing agents should not be used in children because of the risk of chemical peritonitis in communicating processus vaginalis peritonei.^[5]

Complications

Infection of a hydrocele may occur but is uncommon. Complications of operations for hydroceles include:

• Wound infection.
• Infertility which may occur with bilateral injury to the vas deferens.
• Testicular atrophy which may occur due to injury to the testicular blood supply.
• Haematoma.
• Temporary or permanent ilio-inguinal or genitofemoral nerve injury due to entrapment or division during inguinal approaches.
• Secondary cryptorchidism due to excessive scar formation.
• Recurrence of the hydrocele after inguinal approaches. This is usually reactive and resolves within several months.

Prognosis

• The prognosis is dependent on the presence of any underlying cause.
• Most congenital hydroceles resolve by the end of the first year of life.^[4]
• Recurrence of a hydrocele after surgery is very uncommon but is more likely after treatment of a large hydrocele.