A hydrocele is an abnormal collection of fluid within the remnants of the processus vaginalis.
- Accumulation of fluid within the tunica vaginalis.
- Affects 1-2% of male neonates.
- A congenital, simple hydrocele usually disappears within the first 1-2 years of life.
- Causes in older boys and men include trauma, epididymo-orchitis, testicular torsion, hernia, varicocele, and testicular tumour.
- Hydroceles in older boys and men may also be due to generalised oedema, such as nephrotic syndrome or heart failure.
- Persistence of the processus vaginalis allows peritoneal fluid to communicate freely with the scrotal portion of the processus.
- They are congenital but may first present in older boys and men as a result of increased intra-abdominal pressure, continuous peritoneal dialysis or fluid overload.
- Due to imbalance between secretion and reabsorption of fluid
- Can occur secondary to minor trauma, testicular torsion, epididymitis, varicocele operation or following a repair of a hydrocele.
Hydrocele of the cord
The processus vaginalis closes segmentally, trapping fluid within the spermatic cord.
Rare; a large hydrocele lies across the internal ring, with both inguino-scrotal and intra-abdominal lobes.
Hydroceles need to be fully investigated if there is any suspicion of an underlying cause. In children, most hydroceles are the communicating type, in which patency of the processus vaginalis allows peritoneal fluid to flow into the scrotum. Non-communicating hydroceles are caused by excessive fluid production within the tunica vaginalis.
- 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.
- Rarely, similar fluid collections can develop along the canal of Nuck in females.
- Scrotal enlargement with a non-tender, smooth, cystic swelling.
- The classic description of a communicating hydrocele is that of a hydrocele that vacillates in size and is usually related to ambulation.
- 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. For example, some prepubertal tumours such as teratomas may transilluminate.
- Differentiating between a hydrocele and an acute scrotal problem such as testicular torsion or strangulated hernia is very important.
- See separate Lumps in the Groin and Scrotum article.
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.
- Doppler ultrasound studies help to distinguish hydroceles from varicocele and testicular torsion, although these conditions may also be accompanied by a hydrocele.
- 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.
- Many hydroceles in infancy resolve before the age of 2 years and so observation and non-intervention are usually appropriate for hydroceles in infants.
- A scrotal swelling in a baby can lead to parental anxiety. It is very important to reassure parents and given them information regarding hydroceles.
- Early surgery in this age group is indicated if there is suspicion of an associated inguinal hernia or underlying testicular pathology.
- 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.
- 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 of a hydrocele can be performed by one of the following:
- 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.
- Scrotal approach with excision or eversion and suturing of the tunica vaginalis:
- This is recommended for secondary 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.
- Scrotal aspiration and sclerotherapy of the hemiscrotum, using tetracycline or doxycycline solutions:
- Recurrence after sclerotherapy, pain and epididymal obstruction can occur.
- There is a great need for further research to assess the effectiveness of different types of sclerosant agents, sclerosing solution concentration and injection volume for the treatment of hydroceles.
- This procedure is often 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.
NB: Laparoscopic hydrocele repair has shown to be effective in children with satisfactory long-term results.
Infection of a hydrocele may occur but is uncommon.
Complications of operations for hydroceles are very uncommon and may 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.
- 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.
- The prognosis is dependent on the presence of any underlying cause.
- Most congenital hydroceles resolve by the end of the first year of life.
- Recurrence of a hydrocele after surgery is very uncommon but is more likely after treatment of a large hydrocele.
Further reading and references
Guidelines on Paediatric Urology; European Association of Urology (2015)
Rafailidis V, Apostolou D, Charsoula A, et al; Sonography of the scrotum: from appendages to scrotolithiasis. J Ultrasound Med. 2015 Mar34(3):507-18. doi: 10.7863/ultra.34.3.507.
Basta AM, Courtier J, Phelps A, et al; Scrotal swelling in the neonate. J Ultrasound Med. 2015 Mar34(3):495-505. doi: 10.7863/ultra.34.3.495.
Shakiba B, Heidari K, Jamali A, et al; Aspiration and sclerotherapy versus hydrocoelectomy for treating hydrocoeles. Cochrane Database Syst Rev. 2014 Nov 1311:CD009735. doi: 10.1002/14651858.CD009735.pub2.
Yang XD, Wu Y, Xiang B, et al; Ten year experience of laparoscopic repair of pediatric hydrocele and the long-term follow-up results. J Pediatr Surg. 2015 Nov50(11):1987-90. doi: 10.1016/j.jpedsurg.2015.07.007. Epub 2015 Jul 14.