Canal of Nuck Abnormalities

A Case Report of Female Hydrocele of the Canal of Nuck (Type I): A Diagnostic Challenge and Surgical Solution

The canal of Nuck is an anomaly of the female inguinal canal that can lead to the development of hernias or hydroceles. It is a result of incomplete obliteration of a pouch of the parietal peritoneum that accompanies the round ligament throughout the inguinal canal. This is a case report of a 27-year-old female with hydrocele of the canal of Nuck which was initially misdiagnosed as a reducible right inguinal hernia. Physical examination and ultrasound revealed a right groin 64 × 15 × 36 mm cystic mass extending from the right inguinal region to the labia majora. Right inguinal exploration was performed with an oblique inguinal incision. A cystic lesion measuring 65 × 15 mm was carefully dissected from the round ligament and excised. Histopathological examination confirmed the diagnosis of hydrocele of the canal of Nuck. The patient is doing well after six months with no signs of recurrence on the operated side. The hydrocele of the canal of Nuck, though a rare condition, should always be considered in the differential diagnosis when evaluating inguinolabial swellings in female patients.

Hydrocele of the Canal of Nuck: A Review

Canal of Nuck abnormality is a rare surgical condition. The pathologies are mostly encountered in young girls, less than five years of age. The incidence is even less in adults. Various pathologic conditions related to the failure of processus vaginalis obliteration can occur, involving herniation of intraabdominal structures including intestinal and genital contents such as the uterus, fallopian tube, and ovary and hydrocele of the canal of Nuck.

According to its rarity, hydrocele of canal of Nuck is often misdiagnosed for common groin masses. This review summarizes and simplifies embryology, the pathophysiology of the canal of Nuck abnormalities, imaging findings, and treatment options with emphasis on the hydrocele. 

Cyst of the canal of Nuck: an atypical course with cyclic changing of size

As the canal of Nuck normally obliterates before birth, a patent canal is a rare anatomic variant in adult women analogue to the patent processus vaginalis in men. In a patent canal of Nuck, pathologies such as hernias and cyst can build within time. Such cysts themselves are so uncommon that they are mostly described in case reports. Normally, cysts of the canal of Nuck present as a consistent, inguinal swelling with or without pain. Interestingly, in our case, the painful swelling was cyclic changing from the size of a plum to being clinically undetectable within the course of a day. To the best of our knowledge, this is the first description of such an unusual course. The cyst was removed operatively via an open approach. The spasms declined shortly after the operation. At 1 year postoperatively, the patient was still asymptomatic.

Canal of Nuck Abnormalities in Pediatric Female Patients

A groin lump is not an uncommon condition in girls and female infants, and US plays a fundamental role in its exploration. The main pathologic conditions are related to the failure of obliteration of the canal of Nuck. Radiologists should gain a full understanding of the embryology and US anatomy of the inguinal canal before assessing this entity for the first time. An optimal age-adjusted US technique-including examinations at rest and during straining-is essential to help assess the canal of Nuck, diagnose a hernia, and analyze its content. The radiologist must be aware of the various types of hernial content depending on the patient's age, including intestinal, omental, ovarian, or tubouterine hernia, and the US features of each. Incarcerated hernias are common in girls and mostly contain an ovary. In such cases, it is crucial to screen for US signs suggestive of ovarian ischemic damage, thereby calling for urgent surgery. US can also depict a cyst or hydrocele of the canal of Nuck and its complications. Moreover, other rare pathologic conditions involving the inguinal area may be depicted at US, which helps guide appropriate treatment. US is the ideal modality for evaluating an inguinal lump in girls and female infants. Online supplemental material is available for this article. ©RSNA, 2022.

Ultrasound imaging for inguinal hernia: a pictorial review

Inguinal hernia is the most prevalent type of abdominal wall hernia. Indirect inguinal hernia is twice as common as direct inguinal hernia. Computed tomography and magnetic resonance imaging can be used to evaluate inguinal hernia, but these modalities are greatly limited by their cost and availability. Ultrasonography has emerged as the most convenient imaging tool for diagnosing inguinal hernia due to its advantages, such as portability and absence of radiation. The present pictorial review presents an overview on the use of ultrasonography in the evaluation of inguinal hernia with a particular emphasis on the regional anatomy, relevant scanning tips, identification of subtypes, postoperative follow-up, and diagnosis of pathologies mimicking inguinal hernia.

Hydroceles of the Canal of Nuck in Adults-Diagnostic, Treatment and Results of a Rare Condition in Females

Nuck’s hydroceles, which develop in a protruding part of the parietal peritoneum into the female inguinal canal, are rare abnormalities and a cause of inguinal swelling, mostly resulting in pain. They appear when this evagination of the parietal peritoneum into the inguinal canal fails to obliterate. Our review of the literature on this topic included several case reports and two case series that presented cases of Nuck hydroceles which underwent surgical therapy. We present six consecutive cases of symptomatic hydroceles of Nuck’s canal from September 2016 to January 2020 at the Department of Surgery of Charité Berlin. Several of these patients had a long history of pain and consecutive consultations to outpatient clinics without diagnosis. These patients underwent laparoscopic or conventional excision and if needed simultaneous hernioplasty in our institution. Ultrasonography and/or Magnetic Resonance Imaging were used to display the cystic lesion in the inguinal area, providing the diagnosis of Nuck’s hydrocele. This finding was confirmed intraoperatively and by histopathological review. Ultrasound and magnetic resonance imaging (MRI) captures, intraoperative pictures and video of minimal invasive treatment are provided. Nuck’s hydroceles should be included in the differential diagnosis of an inguinal swelling. We recommend an open approach to external Type 1 Nuck´s hydroceles and a laparoscopic approach to intra-abdominal Type 2 Nuck hydroceles. Complex hydroceles like Type 3 have to be evaluated individually, as they are challenging and the surgical outcome is dependent on the surgeon’s skills. If inguinal channel has been widened by the presence of a Nuck’s hydrocele, a mesh plasty, as performed in hernia surgery, should be considered.