Urethral Caruncle and Diverticulum
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Direct answer
A urethral caruncle is a small, red, friable polyp at the external urethral meatus, seen mainly in postmenopausal women. A urethral diverticulum is an acquired cystic outpouching of the urethra into the anterior vaginal wall. Caruncles cause spotting, dysuria or bleeding and usually respond to topical oestrogen. Urethral diverticulum classically presents with dysuria, dyspareunia and post-micturition dribbling, and MRI confirms the diagnosis before surgical excision.
What you must remember
- Caruncle features: a small, red, friable, polypoid lesion at the meatus that bleeds on contact and causes spotting.
- Caruncle cause: oestrogen deficiency after menopause, so topical oestrogen is the first step in management.
- Caruncle malignancy: biopsy any persistent, ulcerated or pigmented lesion, since malignancy is rare but must be excluded.
- Diverticulum origin: usually acquired, following infection and obstruction of periurethral glands, forming a sac that communicates with the urethra.
- Three Ds: dysuria, dyspareunia and post-micturition dribbling, though all three together are uncommon; purulent urethral discharge on pressure is also typical.
- Examination: a tender, cystic anterior vaginal swelling that may express pus or urine on pressure.
- Investigation: MRI defines size, neck and relation to the urethra; urethrocystoscopy and contrast urethrography add detail.
- Treatment: topical oestrogen for caruncle; transvaginal excision of the sac with closure of its neck for symptomatic diverticulum.
From recurrent infection to excision
A 58-year-old has recurrent dysuria and painful intercourse, with a tender anterior vaginal swelling that discharges pus when pressed. Infection is treated first, but the lesion itself needs imaging and excision. The sequence below follows the usual pathway, and each step narrows the differential before surgery. Histology at the end confirms a benign diverticulum or excludes malignancy.
- Clinical examination: palpate the anterior vaginal wall for a cystic mass and express the urethral meatus to check for discharge.
- Imaging: MRI defines the size, neck and relation of the sac to the urethra, with ultrasound used only as a screening option.
- Urethroscopy: cystoscopy or urethrography shows the communication between urethra and diverticulum.
- Infection control: culture-directed antibiotics treat active infection before surgery.
- Excision: transvaginal excision of the sac with closure of its neck, through an anterior vaginal wall flap, with a Martius fat pad interposed when tissue is poor.
- Histology: send the sac for pathology, since clear cell adenocarcinoma is a recognised though rare complication.
Where the exam tries to catch you
Urethral questions usually reward matching the lesion to its location and the correct first step.
- Trap: giving repeated antibiotics for a persistent caruncle Correct: a caruncle responds to topical oestrogen, and a lesion that persists despite it needs biopsy.
- Trap: labelling a discharging anterior vaginal swelling as a Bartholin abscess Correct: a urethral diverticulum is a suburethral midline swelling in the anterior vaginal wall, whereas a Bartholin abscess lies in the posterolateral vestibule at 4 or 8 o'clock.
- Trap: leaving a symptomatic diverticulum to recur Correct: recurrent infection and dyspareunia are indications for excision of the sac.
Frequently asked questions
What are the three Ds of urethral diverticulum?
The three Ds of urethral diverticulum are dysuria, dyspareunia and post-micturition dribbling, which together classically suggest the diagnosis. A palpable anterior vaginal swelling that expresses pus is also typical, and the full triad is present in only a minority of women. The triad is a common viva favourite.
Why does a urethral caruncle occur mostly after menopause?
Urethral caruncles are linked to oestrogen deficiency after menopause, which is thought to alter the urethral meatal mucosa. Topical oestrogen cream usually reduces the lesion and its bleeding. Biopsy is advised if the caruncle persists despite treatment.
Which investigation best defines a urethral diverticulum?
MRI is the most useful non-invasive investigation for a urethral diverticulum, as it shows the size, neck and relation to the urethra. Urethrocystoscopy and contrast urethrography add further detail. Ultrasound serves only as a screening option.
Can a urethral diverticulum become malignant?
A urethral diverticulum can give rise to clear cell adenocarcinoma, though this is rare. Histology of the excised sac is therefore essential. Persistent or enlarging symptoms in an older woman warrant tissue diagnosis.
How is a symptomatic urethral diverticulum treated?
A symptomatic urethral diverticulum is treated by surgical excision of the sac, usually transvaginally with closure of its neck. Infection is controlled with antibiotics before surgery. Excision removes the source of recurrent infection and dyspareunia.