Hydrocele of the Canal of Nuck (Female Hydrocele): A Rare Differential for Inguino-Labial Swelling

Abstract

A three-year-old girl was referred to our surgery department from a rural hospital in West Bengal for a suspected incarcerated rightsided inguinal hernia in March '2014. Her mother had first noticed a peanut sized swelling in the right groin 6-months back; it gradually enlarged to reach the present size [Table/ Fig-1]. Her parents sought medical attention because of moderate pain in her right groin for last 4-days. There were no complaints of abdominal pain, distension of abdomen or vomiting. The patient did not have any history of trauma to the right inguinal region. There was no change in her bowel and bladder habit in last four days. Local examination revealed a pear shaped 5 × 2.5 cm irreducible, fluctuent swelling in the right inguino-labial region. There was no expansile impulse on straining (crying). The swelling was transilluminant but no thrill or bruit was noted over the swelling. Overlying skin was normal and free from the groin lump. Her complete blood count and urinalysis was normal. A differential diagnosis of an inguinal hernia or hydrocele was made from the aforesaid clinical picture. Then the patient was shifted to our emergency operation theatre where ultrasonography of the right inguino-labial region revealed hypoechoic swelling with fine internal septations.Then she underwent surgical exploration through right groin transverse skin crease incision, where after cutting the skin and The inguinal canal is traversed by the spermatic cord in men and the round ligament of uterus in women. The round ligament is attached to the uterine cornu near the origin of fallopian tube at one end and to the ipsilateral labia majora at the other. The round ligament accompanies a pouch of parietal peritoneum in the inguinal canal, which is known as 'canal of nuck'. It is analogous to the processus vaginalis in males. Incomplete obliteration of the peritoneal pouch causes indirect inguinal hernia or hydrocele of the canal of nuck; a very rare condition in women. As these types of cases are rarely seen in surgical practice we present a case of such little-known developmental disorder in a three-year-old girl. She presented with irreducible, tender right inguino-labial swelling with tachycardia simulating incarcerated inguinal hernia, which necessitates emergency surgical exploration. On exploration it was found to be an encysted hydrocele of canal of nuck; so although rare, this entity should be considered in differential diagnosis in a female child presented with inguino-labial swelling. Keywords: Encysted hydrocele, Processus vaginalis, Round ligamentsubcutaneous tissue we encountered a cystic lesion. Then we open the right inguinal canal after cutting the external oblique aponeurosis to delineate the extension of the lesion. Cyst was extended down to the right labia majora and it was clearly seen to be an encysted hydrocele of canal of the nuck [Table/ Fig-2], without any evidence of associated inguinal hernia. The cyst was carefully dissected from the round ligament and ligation of canal of nuck done near deep ...

The hydrocele of canal of Nuck: Case report and review of the literature

“…The canal of Nuck usually gets obliterated by birth or during early infancy, gradually in a downward direction, but if this communication remains patent, it may lead to development of an indirect inguinal hernia or hydrocele [1,2,4,5]. Some authors assume that obliteration of the processus vaginalis occurs after the seventh month of gestation, thus accounting for the higher incidence of inguinal hernias in the premature infant [6].…”

“…The differential diagnosis of inguinal masses in a young female patient include Bartholin's cyst, lymphadenopathy, indirect inguinal hernia, post-traumatic hematoma and malignant and benign tumors including lipoma, vascular aneurysm, sarcoma and rarely cystic lymphangioma, leiomyoma and epidermal cyst [1,2,5]. Hydrocele of canal of Nuck may be misdiagnosed as inguinal hernia because of its rarity, lack of clinician's knowledge regarding this entity and paucity of the relevant literature in the surgical textbooks.…”

“…The hydrocele of canal of Nuck is classified into three types [2]: (i) The most common type is the encysted type where there is no communication of the hydrocele with the peritoneal cavity and the cyst may be found anywhere along the course of the round ligament from the deep ring to the labia majora. (ii) The second type is similar to congenital hydrocele seen in male where there is a persistent communication between hydrocele and the peritoneal cavity.…”

“…The inguinal canal is traversed by the spermatic cord in men and the round ligament of uterus in women. The round ligament is attached to the uterine cornu at one end and to the ipsilateral labia majora at the other and accompanies a pouch of parietal peritoneum in the inguinal canal, known as 'canal of Nuck', analogous to the processus vaginalis [2,3].…”

“…The hydrocele of the canal of Nuck is a very rare condition and results from the incomplete failure of obliteration of the distal portion of the canal [1,2]. An imbalance of fluid secretion and absorption by the secretory membrane lining the processus vaginalis leads to the development of a fluid containing sac [3].…”