Hydrocele Overview

Background

A hydrocele is a collection of serous fluid that results from a defect or irritation in the tunica vaginalis of the scrotum.

Hydroceles also may arise in the spermatic cord or the Canal of Nuck.

Pathophysiology

Embryologically, the processus vaginalis is a diverticulum of the peritoneal cavity. It descends with the testes into the scrotum via the inguinal canal around the 28th gestational week, with gradual closure through infancy and childhood. Structurally, hydroceles are classified into three principal types. In a communicating (congenital) hydrocele, a patent processus vaginalis permits the flow of peritoneal fluid into the scrotum. Indirect inguinal hernias are associated with this type of hydrocele. A patent processus vaginalis is present in a non-communicating hydrocele, but no communication with the peritoneal cavity occurs. A hydrocele of the cord, the closure of the tunica vaginalis is defective. The distal end of the processus vaginalis closes correctly, but the mid portion of the processus remains patent. The proximal end may be open or closed in this type of hydrocele. Adult hydroceles are usually late-onset (secondary). Late-onset hydroceles may present acutely from local injury, infections, and radiotherapy; they may present chronically from gradual fluid accumulation. Morbidity may result from chronic infection after surgical repair. Hydrocele can adversely affect fertility.

Frequency

Hydrocele is estimated to affect 1% of adult men in the US. More than 80% of newborn boys have a patent processus vaginalis, but most close spontaneously within 18 months. The incidence of hydrocele is rising with the increasing survival rate of premature infants and with increasing use of the peritoneal cavity for ventriculoperitoneal (VP) shunts, dialysis, and renal transplants.

Sex

Hydrocele is a disease observed only in males.

Age

Most hydroceles are congenital and occur in children aged 1-2. Chronic or secondary hydroceles usually occur in men older than 40.

History

Most hydroceles are asymptomatic or subclinical. Evaluate the onset, duration, and severity of signs and symptoms. Identify any relevant genitourinary (GU) history, sexual history, recent trauma, exercise, or systemic illnesses. The usual presentation is a painless enlarged scrotum. The patient may report a sensation of heaviness or drag. Patients occasionally report mild discomfort radiating along the inguinal area to the mid-portion of the back. Hydrocele usually is not painful; pain may be an indication of an accompanying acute epididymal infection. The size may decrease with recumbency or increase in the upright position. Systemic symptoms such as fever, chills, nausea, or vomiting are absent in uncomplicated hydrocele. GU symptoms are absent in uncomplicated hydrocele.

Physical

Hydroceles are superior and anterior to the testis, in contrast to spermatoceles, which lie superior and posterior to the testis. Hydrocele is bilateral in 7-10% of cases. Hydrocele often is associated with hernia, especially on the right side of the body. The size and the palpable consistency of hydroceles can vary with position. Hydroceles usually become smaller and softer after lying down and become more prominent and tenser after prolonged standing. Systemic signs of toxicity are absent. The patient is typically afebrile with normal vital signs. Abdominal or testicular tenderness is lacking; no abdominal distension is present. Bowel sounds cannot be auscultated in the scrotum unless an associated hernia is present. No erythema or scrotal discoloration is observed unless an infection causes an acute hydrocele.

Transillumination

A light source shines brightly through a hydrocele. Transillumination is common, but it is not diagnostic for hydrocele. Transillumination may be observed with other etiologies of scrotal swelling (e.g., hernia).

Causes

Most pediatric hydroceles are congenital; however, malignancy, infection, and circulatory compromise are possible causes of hydroceles presenting after infancy. Hydrocele of the cord is associated with pathologic closure of the distal processus vaginalis, which allows fluid pooling in the mid portion of the spermatic cord. Communicating hydrocele is caused by failed closure of the processus vaginalis at the internal ring—non-communicating hydrocele results from pathologic closure of the processus vaginalis and trapping of peritoneal fluid. Adult-onset hydrocele may be secondary to orchitis or epididymitis. Hydrocele also can be caused by tuberculosis and by tropical infections such as filariasis. Testicular torsion may cause a reactive hydrocele in 20% of cases. The clinician may be misled by focusing on the hydrocele, which delays the diagnosis of torsion. Tumors, especially germ cell tumors or tumors of the testicular adnexa, may cause hydrocele. Traumatic (i.e., hemorrhagic) hydroceles are common. Ipsilateral hydrocele occurs in as many as 70% of patients after renal transplantation. Radiation therapy is associated with cases of hydrocele. Exstrophy of the bladder may lead to hydrocele. Hydrocele may arise from Ehlers-Danlos syndrome. Hydrocele may result from a change in the type or volume of peritoneal fluid, like in patients undergoing peritoneal dialysis and those with a ventriculoperitoneal shunt.

Other Problems to be Considered

Indirect inguinal hernia Epididymitis Traumatic injury to the testicle

Lab Studies

A differential CBC may indicate the existence of an inflammatory process. Urinalysis may detect proteinuria or pyuria.

Imaging Studies

Inguinal-scrotal imaging ultrasound This study is indicated to confirm the diagnosis. Identifying abnormalities in the testis, complex cystic masses, tumors, appendages, spermatoceles, or associated hernias may be helpful. In the context of pain or testicular bleeding after trauma, an imaging test can differentiate between a hydrocele and an incarcerated bowel.

Doppler ultrasound flow study

This study is recommended to assess perfusion, even if an acute scrotum is clinically unlikely. It must be performed emergently if there is suspicion of testicular torsion or traumatic hemorrhage into a hydrocele or testes. Doppler ultrasound has a sensitivity of 86-100% and a specificity of up to 100%. However, the limited availability of this test within a clinically valuable period reduces its usefulness.

Testicular scintigraphy

This nuclear scan is beneficial if testicular torsion is suspected, especially in children. Decreased or absent flow to one testis or a testicular pole indicates torsion. Sensitivity for torsion can be 90%, but it is reduced with infancy, early torsion, incomplete torsion, and following detorsion. The specificity for torsion can be 90%, but it is decreased in the presence of scrotal fluid collections (e.g., hydrocele, hernia, abscess, hematocele). Abdominal x-ray findings usually are normal in patients with hydrocele. If films demonstrate an obstructive gas pattern, they may help to differentiate between incarcerated hernia and hydrocele.

Procedures

Transillumination

A light source shined through the scrotum, causing the hydrocele to illuminate. The bowel also may transilluminate; thus, positive transillumination findings are not diagnostic of hydrocele. Positive transillumination findings should not stop the clinician from investigating serious causes or comorbid conditions that may be associated with secondary hydrocele. This procedure is not reliable for the final diagnosis.

Hydrocele aspiration

Aspiration of a hydrocele reveals a clear amber fluid. Aspiration is not therapeutic because the fluid generally reaccumulates quickly. Aspiration of hydroceles is not recommended because it is associated with a high rate of immediate recurrence and with a risk of introducing an infection. If an associated hernia is present, the risk of perforating a loop of the bowel also exists.

Emergency Department Care:

Differentiating between a hydrocele and an acute scrotum (e.g., testicular torsion, strangulated hernia) is essential. As many as 50% of acute scrotum cases are initially misdiagnosed. Transillumination is not diagnostic and cannot rule out an acute scrotum. Ultrasound anatomic imaging with Doppler evaluation of testicular blood flow is indicated when an acute scrotum is suspected, as follows: A traumatic hemorrhage into a hydrocele or testes A testicular torsion with or without a secondary hydrocele An ischemic testicle In children, hydrocele is treated through inguinal incisions with high ligation of the patent processus vaginalis and excision of the distal sac.

Consultations

Immediately consult an urologist if testicular torsion is found or suspected. A urologic follow-up examination is required if any testicular pathology is involved. A general surgery evaluation is indicated for patients with a tense hydrocele that threatens to embarrass the scrotal circulation. Surgical evaluation is also indicated for hydrocele producing a large and bulky mass that is unsightly or uncomfortable.

Further Outpatient Care

Arrange for quarterly follow-up examinations until a decision for or against surgery is made. Spontaneous closure is unlikely in children older than 1 year. Observe infants with hydrocele for 1-2 years or until definite communication is demonstrated. Watch for a concomitant hernia.

Complications

An extremely large hydrocele may impinge on the testicular blood supply. The resulting ischemia can cause testicular atrophy and subsequent impairment of fertility. Hemorrhage into the hydrocele can result from testicular trauma. Incarceration or strangulation of an associated hernia may occur.

Surgical complications

Accidental injury to the vas deferens can occur during inguinal surgery for hydrocele. Postoperative wound infections occur in 2% of patients undergoing surgery for hydrocele. Postoperative hemorrhagic hydrocele is not uncommon, but it usually resolves spontaneously. Direct injury to the spermatic vessels may occur.

Prognosis

The prognosis for congenital hydrocele is excellent. Most cases are resolved by the end of the first year of life. Persistent congenital hydrocele can be readily corrected surgically. The prognosis of hydrocele presenting later in life depends upon its etiology. Adult-onset hydrocele is not uncommonly associated with an underlying malignancy.

Medical/Legal Pitfalls

In a patient with signs and symptoms of an acute scrotum, a hydrocele and a finding of positive transilluminate do not rule out testicular torsion. Immediate definitive tests are indicated to rule out torsion because testicular survival is poor after 4 hours of ischemia. A reasonable search for possible etiologies should be documented. Document a discussion with the patient regarding the need to follow up with an urologist to rule out comorbid conditions (e.g., infections, tumors, hernia, and circulatory compromise)

Special Concerns

Pediatric: Most cases are resolved without intervention.
Geriatric: Hydroceles in this group rarely resolve without surgical intervention.

Normal scrotum

The processus vaginalis and tunica vaginalis are obliterated and contain no fluid.

Non-communicating hydrocele

The processus vaginalis is obliterated, so fluid cannot move between the abdomen and the scrotum, but the tunica vaginalis contains fluid.

Communicating hydrocele

The processus vaginalis is still open, allowing fluid to move between the abdomen and the tunica vaginalis in the scrotum.