A urethral diverticulum is a condition where the

urethra The urethra (from Greek οὐρήθρα – ''ourḗthrā'') is a tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males. In human females and other primates, the urethra c ...

or the periurethral glands push into the connective tissue layers ( fascia) that surround it.

Signs and symptoms

Urethral diverticula are often asymptomatic and symptoms that are present tend to be nonspecific. They can co-occur with cancer, in approximately 6-9% of cases, most commonly adenocarcinoma, but also including squamous cell carcinoma and

transitional cell carcinoma Transitional cell carcinoma, also called urothelial carcinoma, is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. It accounts for 95% of ...

. Approximately 10% of cases co-occur with

kidney stones Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a calculus (medicine), solid piece of material (kidney stone) develops in the urinary tract. Kidney stones typically form in the kidney and leave the ...

. There are 2 types of urethral diverticulums. Congenital and acquired. In infancy usually the urethral diverticulum is congenital but in rare instances acquired urethral diverticulum can be seen in infancy specially following traumatic catheterization. Common symptoms of urethral diverticulum include incontinence, urinary frequency and urgency, pain during sex, and pain during urination. Other symptoms include pain localized to the urethra or pelvis and frequent

urinary tract infection A urinary tract infection (UTI) is an infection that affects part of the urinary tract. When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as a kidne ...

. When urethral diverticulum becomes severe, a painful mass can sometimes be felt inside the

introitus An introitus is an entrance into a canal or hollow organ Organ may refer to: Biology * Organ (biology), a part of an organism Musical instruments * Organ (music), a family of keyboard musical instruments characterized by sustained tone ** Elec ...

of the vagina, which can discharge

pus Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during bacterial or fungal infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection ...

. If the mass is hard or bleeds, complications like cancer or

may be present.

Causes

Few urethral diverticula are present at birth; the vast majority are acquired. Acquired urethral diverticula can be caused by trauma and/or infection. When the peri-urethral ducts become infected repeatedly, they can become blocked and eventually cause a diverticulum. They are usually found in the middle of the urethra or the end farthest from the bladder. Congenital urethral diverticula can arise from several embryological sources. These include defects in the primordial folds and remnants of

Gartner's duct Gartner's duct, also known as Gartner's canal or the ductus longitudinalis epoophori, is a potential embryological remnant in human female development of the mesonephric duct in the development of the urinary and reproductive organs. It was disco ...

Pathology

Histopathologically, several characteristics are frequently visible in urethral diverticula. These include nephrogenic adenoma,

chronic inflammation Chronic systemic inflammation (SI) is the result of release of pro-inflammatory cytokines from immune-related cells and the chronic activation of the innate immune system. It can contribute to the development or progression of certain conditions ...

associated with

fibrosis Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of perma ...

around the glands, small or absent epithelium, chronic cystitis,

cystitis cystica Cystitis cystica is a relatively common chronic reactive inflammatory disorder thought to be caused by chronic irritation of the urothelium because of infection, calculi, outlet obstruction, or tumor resulting in multiple small filling defects in t ...

cystitis glandularis Cystitis glandularis is the transformation of mucosal cells lining the urinary bladder. They undergo glandular metaplasia, a process in which irritated tissues take on a different form, in this case that of a gland. The main importance is in the ...

squamous metaplasia Squamous metaplasia is a benign non-cancerous change (metaplasia) of surfacing lining cells ( epithelium) to a squamous morphology. Location Common sites for squamous metaplasia include the bladder and cervix. Smokers often exhibit squamous ...

, and adenomatous metaplasia. Approximately 1/3 of diverticula are compound or multiple, and some can extend to surround the urethra.

Diagnosis

Urethral diverticulum is often an incidental finding. It can be diagnosed using magnetic resonance imaging and/or micturating cystourethrography. Other studies that can be used to diagnose urethral diverticulum include intravenous urography,

urethroscopy Urethroscopy is examination of the interior of the urethra, and sometimes also the bladder The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination ...

, and/or

ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...

. Conditions that should be distinguished from urethral diverticulum in a differential diagnosis include

overactive bladder Overactive bladder (OAB) is a condition where there is a frequent feeling of needing to urinate to a degree that it negatively affects a person's life. The frequent need to urinate may occur during the day, at night, or both. If there is loss ...

, Gartner's duct cyst, Gartner's duct abscess, ectopic caeco-ureterocele,

interstitial cystitis Interstitial cystitis (IC), a type of bladder pain syndrome (BPS), is chronic pain in the bladder and pelvic floor of unknown cause. It is the urologic chronic pelvic pain syndrome of women. Symptoms include feeling the need to urinate right aw ...

, pelvic inflammatory disease, endometriosis, and cancer.

Treatment

The primary treatment for urethral diverticulum is surgical. In women the surgery is conducted transvaginally, usually when there is no acute inflammation to better aid dissection of the delicate tissues.

Prognosis

Left untreated, urethral diverticulum can cause significant morbidity (sickness). During surgery, there is a risk for complications due to the highly vascular nature of the tissue. The urethral sphincters and its smooth muscle, as well as the neck of the bladder, can be injured regardless of the surgical approach. Other complications from surgery can include

urinary incontinence Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It has been identified as an important issue in geri ...

, stress incontinence, a urethrovaginal fistula, or recurrent diverticula. Horseshoe-shaped diverticula and diverticula that completely surround the urethra are both associated with worse outcomes, as are those located close to the bladder, and large (over 3–4 cm) diverticula.

Epidemiology

The incidence of urethral diverticulum has been increasing in the 2000s, likely due to increasing diagnosis and detection of the condition. It is estimated to be present in as low as 0.02% of all women and as high as 6% of all women, and 40% of women with lower urinary tract symptoms. Most symptomatic urethral diverticula are present in women from 30 to 60 years old. 84% of periurethral masses are due to urethral diverticula.

In men

Urethral diverticulum can occur in men, and can cause complications including

and urinary tract infections.

References

{{Reflist Gynaecology