Bladder herniation into the inguinal canal - CT findings

Clinical History

76-year-old male patient who was operated for right-sided inguinal hernia 2 months before came to the surgical department after he had observed swelling in both inguinal regions but mostly on right side, and increase in scrotal size. No urinary complaints.

Imaging Findings

CT revealed a left inguinal hernia with fluid density lesion continuous with left lateral bladder wall. The left lower part of the bladder is seen extending into the left inguinal canal. The neck of the hernia sac is clearly identified. Bladder is the only content of the hernia sac. No bowel/omentum was contained in the hernia.

There was also a right-sided inguinal hernia containing a small intestinal loop. A large right-sided hydrocele is found in the scrotum.

Discussion

BACKGROUND:

Herniation of the urinary bladder and ureter in inguinal canal or scrotum has rarely been reported. It is reported to be present in 0.4–3% of the general population [1]. There have not been any findings suggesting it to be congenital, so it is widely accepted to be an acquired pathology [2].

Most bladder hernias involve the inguinal and femoral canals, the latter being more frequent in women, and a predilection for the right side has been reported. However, herniations through ischiorectal, obturator, and abdominal wall openings have also been described. Any portion of the bladder may herniate, from a small portion or a diverticulum to the largest part of the bladder [3].

CLINICAL PERSPECTIVE:

Most bladder hernias are asymptomatic and discovered incidentally during surgery or during imaging studies performed for other purposes. Symptoms such as dysuria, frequency, urgency, nocturia, and haematuria have been reported [3, 4].

IMAGING PERSPECTIVE:

Pointing of the bladder toward the side of the hernia i.e. angulation of the base of the bladder anteriorly and inferiorly is the CT sign of a bladder herniation. In patients with large lesions, it is possible to follow the bladder down into the inguinal or femoral canal. Even in the absence of contrast medium in the herniated bladder, identification of its thick wall surrounding unopacified urine can suggest the diagnosis [3].

USG is usually requested to characterise the nature of a scrotal mass. Diagnostic criteria include the presence of a fluid-filled lesion at the scrotum that can often be followed cranially to join the intraabdominal portion of the bladder [3].

The high resolution provided by MRI can allow analysis of the relationship of the hernia to the inferior epigastric vessels, thus classifying the lesion as direct or indirect according to its position (medial or lateral) in relation to the vascular landmarks [3].

Retrograde cystography is usually considered the best imaging technique for a bladder hernia [3].

OUTCOME:
The preoperative diagnosis of bladder herniations is important in order to prevent the possible iatrogenic trauma that can occur during surgery. Surgical repair is the standard treatment for inguinal hernias involving the bladder [5].

Differential Diagnosis List

Final Diagnosis

Urinary bladder herniation into the left inguinal canal

URL:	https://eurorad.org/case/10736
DOI:	10.1594/EURORAD/CASE.10736
ISSN:	1563-4086