Urethral diverticulum

Question 1

Aetiology of UD

Answer 1

The aetiology of #UD remains largely unknown, but it is thought it may be congenital or acquired in origin.

Question 2

UD congenital causes

Answer 2

Congenital cases may occur from remnants of Gartner’s duct or abnormal union of primordial folds or persisting cell rests, especially Müllerian, but they are rarely found in children.

Question 3

UD acquired causes

Answer 3

It is three times higher in Black American compared with White American women, suggesting a genetic sus- ceptibility in this population.

1 - Most cases are acquired and result from repeated infections and obstruction of the periurethral glands. These rupture into the urethral lumen and the cyst epithelialises and persists.

2 - Traumatic childbirth, especially with assisted delivery, has been suggested as a cause of UD development, but it may equally develop in nulliparous patients.

3 - UD has also been reported following trans- urethral collagen injection for stress urinary incontinence.

Question 4

UD anatomy

Answer 4

The UD usually dissects within the urethral pelvic ligament with the orifice/neck just off centre at 4 and 8 o’clock. Occasionally it may extend proximally beneath the bladder neck and trigonal area. Most UD have a single connection to the urethra and vary in size and shape. Complex patterns may occur with multiple ostia; UD may be multiple and loculated and may extend partially (‘saddlebag’ or ‘horseshoe’) or circumferentially around the urethra and thereby compromise urethral sphincter function. They are usually lined by urothelium, but squamous and glandular metaplasia can occur and even leiomyoma.

Question 5

UD symptoms

Answer 5

UD may present with multiple symptoms. The historical classical triad of dys- uria, post-void dribbling and dyspareunia is only seen in a minority of patients. Lower urinary tract symptoms (LUTS), namely, frequency and urgency, are present in 40–100 % of cases