What are the other Names for this Condition? (Also known as/Synonyms)

• Female Hydrocele (Cyst of the Canal of Nuck)
• Female Hydrocele of the Canal of Nuck
• Hydrocele in the Canal of Nuck

What is Hydrocele of the Canal of Nuck? (Definition/Background Information)

• Hydrocele of the Canal of Nuck is a rare, benign, fluid-filled lesion that forms in the inguinal canal in females. The inguinal canal is a short passage (for conveying various structures) of the abdominal wall in the groin region
• The fluid-filled lesion is also commonly referred to as the Female Hydrocele (Cyst of the Canal of Nuck), which is equivalent to the male hydrocele of the spermatic cord. The condition was identified by Dutch anatomist Anton Nuck in the 17th century
• There are no clearly established risk factors, but Hydrocele of the Canal of Nuck is associated with inguinal hernia (a bulge made-up of soft tissue, typically located in the groin region)
• Hydrocele of the Canal of Nuck is a developmental defect that occurs due to persistence of the processus vaginalis (a pouch-like structure in the peritoneum, seen during fetal growth and development) after birth of the child
• The signs and symptoms of Hydrocele of the Canal of Nuck include the presence of a painless mass of variable size in the groin region. Large cysts may cause abdominal pain and discomfort. Rarely, the cystic mass may get infected leading to abscess formation with pain and inflammation
• Treatment course includes close observation of the tumor in asymptomatic cases and surgical management, if necessary. In general, the prognosis of Hydrocele of the Canal of Nuck is excellent with adequate treatment

Who gets Hydrocele of the Canal of Nuck? (Age and Sex Distribution)

• Hydrocele of the Canal of Nuck is a rare condition that is exclusive to females; much less than 450 cases have been described in the medical literature
• The condition is mostly observed in babies, young girls, and young adult women (age range of 12 months to 25 years)
• However, it may be also occasionally diagnosed in older women and in newborn children
• There is no known geographical, ethnic, or racial preference

What are the Risk Factors for Hydrocele of the Canal of Nuck? (Predisposing Factors)

• No definitive risk factors have been identified for Hydrocele of the Canal of Nuck
• However, one-third of the cases may be associated with inguinal hernia (a condition that often complicates the diagnosis). Hydrocele of the Canal of Nuck is sometimes referred to as an ‘indirect inguinal hernia’

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hydrocele of the Canal of Nuck? (Etiology)

Hydrocele of the Canal of Nuck is reported to be a developmental disorder that occurs during fetal development in the womb.

• The condition forms due to partial remnant of a structure called processus vaginalis (peritoneal pouch) that forms finger-like projections from the peritoneal layers of the abdominal cavity into the groin (inguinal) area
• Normally, the projection disappears during the fetal growth and development, or following delivery (within 12 months) as the baby grows
• If the patent processus vaginalis remains persistent after birth, it gives rise to Hydrocele of the Canal of Nuck; the cyst develops when there is fluid accumulation. However, it is important to note that not all patent processus vaginalis form into a hydrocele/hernia

What are the Signs and Symptoms of Hydrocele of the Canal of Nuck?

The following signs and symptoms of Female Hydrocele of the Canal of Nuck may be noted:

• Presence of a solitary fluctuant (fluid-filled) mass in the inguinal/groin region
• The cyst is soft, oval-shaped, and well-defined. It does not connect to the abdominal cavity
• When coughing/straining, the cyst remains stable in size and shape. This also indicates that it is not connected with the peritoneum (abdominal cavity)
• The cysts may be of varying sizes; most cysts are small (about 1-2 cm), while some may grow to large sizes (6 cm or more) even in young girls
• The swollen mass is not painful to touch in most cases
• No visible bulge may be seen when the child is in a standing position; which may help the healthcare provider rule out a hernia
• Also, no nausea and vomiting is noted with Hydrocele of the Canal of Nuck
• Rarely, large sizes may cause discomfort and pain from pressure to the region (mass effect). It may cause discomfort while walking or sitting

How is Hydrocele of the Canal of Nuck Diagnosed?

A diagnosis of Hydrocele of the Canal of Nuck may involve the following steps:

• Evaluation of the individual’s medical history and a thorough physical (groin region) examination
• Ultrasound scan of the inguinal region: A color Doppler sonography is considered to be an effective tool to diagnose the condition
• Transillumination test (for larger cysts), wherein a flashlight is shone to illuminate the cyst, which glows because of the presence of a clear fluid
• Magnetic resonance imaging (MRI) scan of the abdomen and pelvis: MRI uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor
• Biopsy of the mass: A tissue biopsy of the cystic mass is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Occasionally, since the cyst is fluctuant (due to accumulation of fluid), a fine needle aspiration of the cyst contents may be performed
  • Fine needle aspiration (FNA) biopsy: A very fine and hollow needle is inserted where the cyst is noticed; the fluid contained within the cyst is withdrawn. The extracted sample is sent for further pathological examination
  • If the healthcare provider suspects an infection process, then culture studies on the cyst aspirate may be performed

A differential diagnosis, to eliminate other conditions is considered, before arriving at a conclusion. Tests and exams for the following medical conditions and tumors may be evaluated:

• Endometriosis
• Enlarged lymph nodes
• Femoral hernia, inguinal hernia
• Ganglion cyst of hip joint
• Leiomyoma
• Lipoma

Note: In some cases, a diagnosis of Hydrocele in the Canal of Nuck has taken place when the patient was being operated upon for a suspected inguinal hernia.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hydrocele of the Canal of Nuck?

No significant complications of Hydrocele of the Canal of Nuck are noted, because it is a benign condition. However, the following may be observed in some cases:

• Stress due to a concern for inguinal hernia
• Very rarely, abscess formation resulting in infections; this may result in associated signs and symptoms including fever, pain, and inflammation
• Damage to the muscles, vital nerves, and blood vessels, during surgery
• Post-surgical infection at the wound site is a potential complication
• Recurrence of the cyst following surgery is not known to occur

How is Hydrocele of the Canal of Nuck Treated?

Treatment measures for Hydrocele of the Canal of Nuck may include the following:

• Some cysts are known to subside and spontaneously regress on their own in very young children
• If there are no symptoms, then the healthcare provider may advise a ‘wait and watch’ approach, following the diagnosis of a Female Hydrocele
• In some cases, the cysts may get secondarily infected. If bacteria is the cause of infection, it may be treated through antibiotics (antibiotic therapy)
• If the antibiotics do not clear the infection, then abscess drainage through a surgical procedure may be performed. Sonography-guided aspiration of cyst content may result in recurrence of fluid accumulation (which can take place slowly over 12-18 months)
• Surgical intervention with complete excision can result in a complete cure. The type of surgery performed is known as hydrocelectomy with high ligation of hernial sac
• Post-operative care is important: Minimum activity level is to be ensured until the surgical wound heals
• Follow-up care with regular screening and check-ups are important

How can Hydrocele of the Canal of Nuck be Prevented?

• Current medical research has not established a method of preventing Hydrocele of the Canal of Nuck
• Women with inguinal hernia may be evaluated for Hydrocele of the Canal of Nuck, since there is an association between the two conditions

What is the Prognosis of Hydrocele of the Canal of Nuck? (Outcomes/Resolutions)

• The prognosis of Hydrocele of the Canal of Nuck is excellent with surgical treatment (removal through simple excision), since it is a benign lesion
• Recurrence of the cyst following surgical intervention (complete excision) is not known to occur

Additional and Relevant Useful Information for Hydrocele of the Canal of Nuck:

The following DoveMed website links are useful resources for additional information:

http://www.dovemed.com/healthy-living/womens-health/

http://www.dovemed.com/diseases-conditions/cancer/