Canal of Nuck hernia: a multimodality imaging review

Cyst of the canal of Nuck in an adult female patient: A case report on surgical management

INTRODUCTION

The cyst of the canal of Nuck is a rare cause of inguino-labial swelling in adult women, arising from an obliteration failure of the processus vaginalis during embryological development. Its rarity often leads to misdiagnosis and improper treatment. This article highlights its diagnosis and surgical management.

CASE PRESENTATION

A 21-year-old woman presented with a two-month history of symptomatic swelling in the right inguino-labial region, after consulting multiple doctors. Various investigations including abdominal ultrasonography, computed tomography, and Magnetic Resonance Imaging revealed multiloculated cystic lesion with thin walls, without communication to the peritoneal cavity. During surgery, an encysted sack was discovered at the external inguinal ring, with no associated hernia. The cyst was ligated high and excised along with the round ligament. The anatomical defect was repaired without using prosthetic mesh. The patient had an uneventful post-operative recovery at six-months follow-up.

DISCUSSION

The encysted hydrocele (Type 1) is the most common among the three types of canal of Nuck hydroceles. This rare entity should be considered in the differential diagnosis of groin masses, even in adult women. Ultrasonography is often used initially, while Magnetic Resonance Imaging is reserved for complex cases. Surgical intervention is essential for both diagnosis and treatment, with dissection extending up to the deep inguinal ring to address any associated hernias. The choice between open or laparoscopic procedures depends on the nature of the defect.

CONCLUSION

Surgery remains the sole standard therapeutic approach for the management of the cyst of the canal of Nuck.

Cyst of the Canal of Nuck: a case report

The cyst of the Canal of Nuck, or hydrocele, is a rare pathological condition in the female inguinal region. We present a 44-year-old female with a cystic lesion in the right inguinal area, detailing clinical symptoms, differential diagnosis and imaging findings. Surgical intervention involved complete cyst excision, with no recurrence during the follow-up. This case underscores the importance of accurate diagnosis and targeted surgical treatment for favourable outcomes in managing rare anatomical variations like the Canal of Nuck cyst.

Totally laparoscopic surgery for a hydrocele of the canal of Nuck extending from the abdominal cavity to the subcutaneous space: a case report

BACKGROUND

Hydrocele of the canal of Nuck (HCN) is a rare disease, and its indications for laparoscopic surgery are not well-established.

CASE PRESENTATION

A 53-year-old woman was referred to our hospital due to an uncomfortable thumb-sized inguinal mass. Preoperative computed tomography scan and magnetic resonance imaging revealed a hydrocele extending from the abdominal cavity around the left deep inguinal ring via the inguinal canal to the subcutaneous space. The patient was diagnosed with HCN protruding into the abdominal cavity and extending to the subcutaneous space. Laparoscopy can easily access the hydrocele protruding into the abdominal cavity. Furthermore, laparoscopic hernioplasty can be superior to the anterior approach for females. Hence, laparoscopic surgery was performed. After transecting the round ligament of the uterus, a tense 3-cm hydrocele was dissected with it. In order to approach the hydrocele distal to the deep inguinal ring, the transversalis fascia was incised medially to the inferior epigastric vessels. The subcutaneously connected hydrocele was excised from the incision. Then, the enlarged deep inguinal ring was reinforced using a mesh with the laparoscopic transabdominal preperitoneal approach. The patient was discharged 2 days postoperatively. Laparoscopic resection can be more effective for a hydrocele protruding into the abdominal cavity as it facilitates an easy access to the hydrocele. Moreover, laparoscopic resection of a hydrocele extending from the inguinal canal to the subcutaneous space via a transversalis fascia incision can be safer, with low risk of injury to the inferior epigastric vessels. The incised transversalis fascia and the enlarged deep inguinal ring due to the HCN were simultaneously repaired with the laparoscopic transabdominal preperitoneal repair. There are two reports on laparoscopic resection via a transversalis fascia incision for HCNs located between the inguinal canal and the subcutaneous space, which does not require intraperitoneal hydrocelectomy. However, this is the first report on laparoscopic resection of large HCNs protruding into the abdominal cavity and extending beyond the inguinal canal into the subcutaneous space via intraperitoneal hydrocelectomy and a transversalis fascia incision.

CONCLUSIONS

Laparoscopic surgery with transversalis fascia incision can be useful for HCNs extending from the abdominal cavity to the subcutaneous space.

Hydrocele of the Canal of Nuck: A report of five cases

INTRODUCTION AND IMPORTANCE

Canal of Nuck hydrocele is a rare condition in females. Due to mild symptoms, it may be neglected, leading to complications, including infection and bleeding. The rarity of this condition, coupled with its potential for adverse outcomes, necessitates a high index of suspicion among treating surgeons to diagnose and promptly manage the case. We present five cases of the canal of Nuck hydrocele.

CASE PRESENTATION

We prospectively studied five cases of the canal of Nuck hydrocele admitted to our surgical department over two years. Three patients presented with painless, non-tender inguinal swelling, while two had tenderness. Three patients had a right-sided canal of Nuck hydrocele, one had a left-sided, and one had bilateral hydroceles. One patient had an associated indirect inguinal hernia. All patients were treated by carefully dissecting the hydrocele from the round ligament, followed by ligation of the canal of Nuck near the deep inguinal ring. The associated hernia was treated using herniotomy. All patients had an uneventful postoperative course with no recorded postoperative wound infection or recurrence.

CLINICAL DISCUSSION

The hydrocele of the Canal of Nuck develops from the failure of complete obliteration of the processus vaginalis in female patients. Most cases are asymptomatic and are usually found incidentally as painless swelling in the inguinolabial region. Surgery is the treatment of choice, as there is an increased incidence of associated complications such as infection and bleeding, and it also helps to confirm the diagnosis. The surgical procedure involves resection of the hydrocele, ligation of the neck of the processus vaginalis, and repair of any associated hernia, if present.

CONCLUSION

The canal of Nuck hydrocele is often overlooked in female pediatric patients with inguinolabial masses. Surgeons must maintain a high index of suspicion and perform prompt ultrasound examinations for an accurate diagnosis. Early surgical intervention is of utmost importance for preventing morbidity.

Bilateral hydrocele of the canal of Nuck: A case report

INTRODUCTION

The hydrocele of the canal of Nuck is a rare cause of bilateral inguino-labial swelling. Due to its rarity, lack of clinician knowledge regarding this entity, and paucity of relevant literature, it can be misdiagnosed and often mistreated.

CASE PRESENTATION

We present a case of a two-year-old female with bilateral inguino-labial swelling who was diagnosed with a hydrocele of the canal of Nuck based on history and clinical examination. The patient underwent bilateral hydrocele excision with high pouch ligation, and she experienced an uneventful recovery.

DISCUSSION

Bilateral hydrocele of the canal of Nuck is rare in females. Diagnosis can be made based on history and clinical findings. In cases of diagnostic uncertainty, preoperative ultrasonography may aid in diagnosis. Management of hydrocele of the canal of Nuck involves surgical intervention, which is necessary for both definitive diagnosis and treatment.

CONCLUSIONS

Although rare, hydrocele of the canal of Nuck must be suspected in cases with inguino-labial swelling, properly diagnosed, and surgically excised. It can be misdiagnosed; therefore, clinicians need to have a high index of suspicion to reach a provisional diagnosis and prevent morbidity and further complications.

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. 

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.

Cyst and endometriosis of the canal of Nuck: rare differentials for a female groin mass

Cyst of the canal of Nuck is a rare abnormality of the female inguinal canal that can present similarly to a hernia. If incompletely obliterated, the patent canal of Nuck may predispose to an inguinal hernia or hydrocele due to direct communication with the abdominal cavity. Such defects are normally detected and repaired in early childhood but can also present later in adult life. We report the case of a 44-year-old woman who presents with a fluctuant, mobile and irreducible left-sided groin mass. Ultrasound of the groin identified a cystic structure in the canal of Nuck. The patient underwent successful open herniorrhaphy with excision of the cyst and mesh repair of the inguinal canal. Subsequent histopathological examination also revealed concurrent endometriosis of the canal of Nuck. A systematic approach to differential diagnoses for a female groin mass, further investigations and management are discussed.

Inguinal endometriosis: Ten case reports and review of literature

BACKGROUND

To describe the characteristics, diagnosis and surgical treatment of inguinal endometriosis (IEM).

CASE SUMMARY

We retrospectively analyzed 10 patients diagnosed with IEM at Beijing Chao-Yang Hospital from 2011 to 2019. Relevant features, symptoms, images, surgical treatment, hormonal therapy and follow-up were collected and discussed. A total of 10 cases of IEM diagnosed by surgery and pathology were characterized by a lesion on the right side (9/11); five patients had symptoms related to the menstrual cycle, and only 3 patients were clearly diagnosed before surgery. Ultrasonography was of little assistance in confirming the diagnosis, but magnetic resonance imaging showed specific, high-intensity patterns. Anatomically, most of the IEM lesions were located in the extraperitoneal ligament (10/11); nine patients had inguinal hernias (IH), five had concurrent or prior pelvic endometriosis, and four had infertility. The clinical results from extensive resection were satisfactory.

CONCLUSION

IEM is an extremely rare condition that can easily be misdiagnosed prior to surgery. A right IH may contribute to the formation of right-sided IEM, and extensive resection involving the round ligament and hernia sac is essential to prevent recurrence.

Endometriosis of the Canal of Nuck: A Systematic Review of the Literature

Endometriosis is a common benign gynecological condition defined as the presence of endometrial tissue in tissues outside the uterine cavity. Apart from the common sites of endometriosis, rare sites other have also been reported including the liver, the thoracic cavity, the muscles, nerves, and more rarely in a patent Nuck canal. We aim to evaluate the clinical presentation, diagnostic features, and management of the Nuck endometriosis. A meticulous search of three electronic databases was performed until May 2020 for articles reporting cases of Nuck endometriosis. A total of 36 patients from 20 studies were analyzed. Median age of patients was 36 years with 33 women being of reproductive age. A right-sided lesion was identified in 30 cases (83.3%), while all patients suffer from a groin mass with cyclic pain in a proportion of 22%. All the patients finally underwent surgery for investigation of the lesion and fixation of the defect. Five cases of malignancy were detected at final pathology. All of them were alive with a median reported overall survival of 37 months. Nuck endometriosis should be included in the differential diagnosis of female patients with groin swelling. An evaluation by a gynecologist is important when endometriosis is suspected.

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.

Herniation of the uterus, ovaries and fallopian tubes into the canal of Nuck in a 4-month-old child: A rare entity

Partial or complete failure of obliteration of the processus vaginalis in the female results in the formation of a potential space known as the canal of Nuck, into which various organs and/or collections can herniate. A 4-month-old female presented with a left labial mass related to herniation of the uterus, ovaries and fallopian tubes through the canal of Nuck. Early diagnosis is important as there is a high risk of ovarian torsion and incarceration.

Added value of MRI for the diagnosis of adnexal torsion in children and adolescents after inconclusive ultrasound examination

PURPOSE

The purpose of this study was to assess the performance of magnetic resonance imaging (MRI) in children and adolescents with suspected adnexal torsion (AT) after inconclusive initial ultrasound examination.

MATERIALS AND METHODS

Twenty-eight girls with a mean age of 12±4 (SD) years (range: 1 month to 18years) were included. All had clinically suspected AT and inconclusive initial ultrasound findings followed by pelvic MRI as a second-line imaging modality. The final diagnosis was obtained by surgery or follow-up. Two radiologists blinded to the clinical, ultrasound and surgical data, retrospectively and independently reviewed MRI examinations. Clinical and MRI features associated with AT were searched for using univariate analyses.

RESULT

Among the 28 patients, 10/28 patients (36%) had AT and 22/28 (79%) had an ovarian or tubal mass. AT was associated with an age<13years (OR: 10.7; 95% CI: 1.3-148.2) (P=0.022) and a whirlpool sign at MRI (OR: 61.0; median unbiased estimate, 7.2) (P<0.0001). When a mass was present, the best quantitative MRI criteria for AT were mass volume and ovary-corrected volume≥30cm³ (κ=0.72 and 0.61, respectively), mass axis length≥5cm (κ=0.90), and mass surface area≥14 cm² (κ=0.58), with moderate to almost perfect interobserver agreement. The overall sensitivity, specificity and accuracy of MRI for the diagnosis of AT were 100% (10/10; 95% CI: 69-100), 94% (17/18; 95% CI: 73-100) and 96% (27/28; 95% CI: 82-100) respectively, with perfect interobserver agreement (κ=1).

CONCLUSION

In pediatric patients with suspected AT and inconclusive initial ultrasound examination, a strategy including MRI as a second-line imaging modality should be considered if MRI does not delay a potential surgery.

Cyst of the Canal of Nuck in adult females: A case report and systematic review

Defects in the Canal of Nuck are rare abnormalities of the female genitalia, which are typically detected and repaired in young age. In the present report, a case of a Nuck cyst in a 40-year old female patient is described. Additionally, the current literature concerning cases of women with hydrocele of Nuck canal was systematically reviewed. A total of 16 case reports of 16 patients with Nuck hydrocele (mean age of 35.18 years), have been reported to date. A right inguinal mass was noted in 13 patients (81.3%) whereas in 3 patients a left-sided mass was noted. The surgical approach was open in 13 cases and laparoscopic in 3 cases. Two cases underwent hydrocelectomy and inguinal ring ligation, whereas in 7 cases a simple cystectomy was performed. In 2 cases the round ligament was excised along with the hydrocele. In one of these 2, ligamentum rotundum necrosis and presence of a haemorrhagic cyst of the canal of Nuck were identified. Hernia repair and hydrocelectomy was performed in 5 cases. A cyst of the Canal of Nuck is relatively rare, but should be considered during the diagnosis of inguinal masses in female patients.

Prenatal Diagnosis of a Cyst of the Canal of Nuck Associated With an Ovarian Cyst and Acute Polyhydramnios

In the female, the canal of Nuck is a tubular fold of parietal peritoneum that travels along with the round ligament through the inguinal canal to its attachment on the labia majora. The canal of Nuck is analogous to the processus vaginalis in the male. In embryonic development, this pathway typically obliterates early in life; however, in some cases, it may partially or completely fail to close. This failure to obliterate can lead to complications ranging from a cyst of the canal of Nuck (also known as a female hydrocele) to herniation and incarceration of abdominal and pelvic organs. There is little information available in the medical literature concerning this rare condition; therefore, it is important for sonographers, physicians, and surgeons to be familiar with this developmental abnormality. This report represents the first prenatal case of a cyst of the canal of Nuck, along with the unique combination of a large left fetal ovarian cyst and acute polyhydramnios. The embryology, incidence, differential diagnosis, management, and treatment of these female conditions are discussed.

Persistence of the processus vaginalis and its related disorders

The processus vaginalis is a blind-ended evagination of the abdominal wall that develops during fetal life and typically undergoes obliteration in early life. Persistence of the processus vaginalis is associated with a number of pathologies including congenital indirect inguinal hernias, communicating hydroceles, funicular and encysted hydroceles, canal of Nuck cysts, and acquired undescended testis. Whilst all are detectable sonographically, there is little educational material relevant to the field of ultrasound with much of the literature directed at surgical and primary care physicians. Furthermore, within the literature there is a lack of consensus on several areas including the anatomy and embryology of the processus vaginalis and the mechanisms behind its obliteration. As such the objective of this paper is to distil the information regarding the persistent processus vaginalis as it is relevant to ultrasound and in doing so address the literature gap for sonographers and sonologists. The anatomy and embryology of the persistent processus vaginalis will be discussed including causative mechanisms for anomalies with their sonographic appearance highlighted.

Canal of Nuck Abnormalities

Canal of Nuck abnormalities are underrecognized causes of labial masses with potential adverse outcomes. The 2 main categories of canal of Nuck abnormalities are hernias and hydroceles. There are 3 types of canal of Nuck hydroceles: communicating, encysted, and bilocular. Canal of Nuck hernia contents vary, but those containing ovaries need urgent medical attention because of an increased risk of ischemia. Ultrasound can establish a definite diagnosis in all cases. This article reviews the embryologic characteristics, anatomy, pathologic characteristics, and imaging features of these abnormalities while providing a clear pictorial depiction of various unique hernias and hydroceles seen with this entity.

Canal of Nuck hernias

The canal of Nuck, caused by the failed closure of the processus vaginalis in the female, is the continued outpouching of parietal peritoneum through the inguinal canal to the labia majora. Disorders of the canal of Nuck include hernia and hydrocele. Some canal of Nuck hernias, especially of the ovary, may result in emergent complications such as incarceration, strangulation, and ovarian torsion. Knowledge of canal of Nuck disorders and prompt diagnosis are important to avoid serious complications. Imaging, especially ultrasound, is essential for timely diagnosis, leading to appropriate management and better patient care.

Nuck Canal Hernias, Typical and Unusual Ultrasound Findings

BACKGROUND

Inguinal hernia in girls is a very rare condition. The cause of this pathology is incomplete closure of the processus vaginalis of the peritoneum, in girls named the canal of Nuck. Failed obliteration of this canal could result in hernia or hydrocele. Also less frequent findings, such as uterus herniated to the canal, were observed.

OBJECTIVE

The purpose of this study was to describe the possible findings in female inguinal hernias and its ultrasound appearance.

METHODS

Thirty-five patients with surgically confirmed hernias of the canal of Nuck were identified at our institution between January 2007 and November 2015. All the patients underwent ultrasonography before surgery.

RESULTS

In 14 cases, there was hydrocele of the canal of Nuck. In 9 cases, intestinal hernia was found. In 10 patients, the hernia content appeared as mass-containing cysts and was confirmed at surgery as ovary. In 1 patient, the ovary was herniated together with uterus. In 1 patient, atypical hypoechoic lesion was found, which turned out to be angiofibrolipoma. In all patients, ultrasound diagnosis was confirmed by surgery.

CONCLUSIONS

Ultrasound examination performed with high-frequency transducer is an examination of choice in female patients with pathological mass in inguinal region.