Urethral Caruncle
Updated: Oct 03, 2022
Author: Kamran P Sajadi, MD; Chief Editor: Edward David Kim, MD, FACS
Overview
Practice Essentials
Urethral caruncles are benign, distal urethral lesions that are most commonly found in postmenopausal women, although rare cases have been reported in girls, and a case of urethral caruncle has also been described in a male.[1, 2, 3] Additionally, urethral caruncles have been reported to occur rarely in premenopausal women and may enlarge during pregnancy. Urethral polyps are the pediatric equivalent of urethral caruncles and manifest in a similar fashion.\Urethral caruncles resemble various urethral lesions, including carcinoma. The differential diagnoses of urethral caruncle include the following:
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Periurethral gland abscesses
Most urethral caruncles are readily diagnosed on physical exam alone, and can be treated conservatively with warm sitz baths and vaginal estrogen replacement. Surgical intervention may be indicated for patients with larger symptomatic lesions and for those with uncertain diagnoses. Possible indications for excisional biopsy include the following:
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Induration
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Failure to respond to conservative therapy
-
Atypical appearance
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Growth over time
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Patient request
Problem
Urethral caruncles, which often originate from the posterior lip of the urethra, may be described as fleshy outgrowths of distal urethral mucosa. They are usually small but can grow to 1 cm or more in diameter.
Relevant Anatomy
The female urethra is a tubular structure 3-4 cm in length. It is normally lined by nonkeratinized stratified squamous epithelium distally and transitional epithelium proximally. Outer layers have a complex network of smooth muscle fibers and vascular structures. The female urethra and surrounding vaginal and vulvovestibular tissue are rich in estrogen receptors.
Pathophysiology
The first step in the development of a urethral caruncle is likely distal, focal urethral prolapse caused by urogenital atrophy due to estrogen deficiency, now known as genitourinary syndrome of menopause. Chronic irritation, where the urethral mucosa is exposed, contributes to the growth, hemorrhage, and necrosis of the lesion.
Epidemiology
Urethral caruncles are common in elderly postmenopausal women but may rarely develop in girls or premenopausal or perimenopausal women.[5, 3] Premenopausal women may develop relative estrogen deficiency due to exogenous oral contraceptives, postpartum state, or during breastfeeding.
Prognosis
The prognosis is excellent if pathology confirms urethral caruncle as the diagnosis.
Presentation
History
Most urethral caruncles are asymptomatic and are incidentally noted on pelvic examination; however, some may be painful and others may be associated with dysuria. Many individuals with a urethral caruncle present with bleeding or, more commonly, with the patient noticing blood on undergarments or with wiping; this may be mistaken for vaginal bleeding.[6]
Urethral caruncles are unlikely to explain voiding or storage symptoms in women. In fact, a comparison of lower urinary tract symptoms and urodynamic factors in incontinent women with and without caruncles found no differences.[7] Isolated case reports of urinary retention from urethral caruncle do exist, however.[8]
Physical Examination
On examination, caruncles most often appear clinically as a pink or reddish exophytic lesion at the urethral meatus (see the image below); in rare cases, they are purple or black secondary to thrombosis. Some caruncular lesions may resemble urethral carcinoma.
Urethral caruncles usually protrude posteriorly (at the 6 o'clock position).
Photographs show the preoperative (a) and postoperative (b) appearance of a urethral caruncle in a 9-year-old girl. Courtesy of Journal of Medical Case Reports, Springer Nature.
DDx
Diagnostic Considerations
Urethral prolapse is similar in appearance to urethral caruncle, but is circumferential while caruncles are focal. Urethral prolapse may occur in prepubescent girls or postmenopausal women, whereas caruncles are seen almost exclusively in the latter.
Reports of neoplastic lesions mimicking urethral caruncles include the following:
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Condyloma acuminatum [9]
Intraepithelial squamous cell carcinoma arising within a urethral caruncle has been reported in two patients.[13]
Urethral leiomyoma masquerading as urethral caruncle have been reported.[14] In addition, urethral caruncles may contain atypical stromal cells, and these pseudoneoplastic lesions must be differentiated from lymphoma or sarcoma.[15]
Cases of urethral tuberculosis[16, 17] and periurethral colonic-type polyp resembling urethral caruncle have rarely been reported.[18, 19]
A rare case of extramedullary plasmacytoma (EMP) initially diagnosed as a urethral caruncle has been reported.[20]
Differential Diagnoses
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Periurethral gland abscesses
Workup
Laboratory Studies
Obtain a urinalysis to rule out urinary tract infection when pain, discomfort, or dysuria is present or when an operative intervention is planned.
Diagnostic Procedures
A urethral caruncle is obvious on physical examination, and biopsy is unnecessary in the vast majority of cases.
Cystoscopy can be performed, either in the office or at the time of excision, to rule out more serious pathologies or when the origin of hematuria is uncertain. Cystoscopy is not necessary when the diagnosis is obvious, hematuria is absent, and no intervention is planned.
Sonography may be helpful in distinguishing urethral caruncle from other solid masses. On ultrasound, urethral caruncles are hypoechoic/isoechoic and rich in blood flow signal.[21]
Histologic Findings
Microscopically, a urethral caruncle resembles a bed of granulation tissue covered by either squamous or transitional epithelium. Infolding of epithelium may create papillary architecture. Inflammatory infiltration is common (see image below).
This image shows marked vascular engorgement and a polymorphous inflammatory infiltrate in the stroma. Surface epithelium is benign. Courtesy of GT MacLennan, MD.
A pathology series of 41 patients demonstrated mixed hyperplastic urothelial or squamous lining.[1] The stroma demonstrated fibrosis, edema, and/or inflammation. Immunohistochemistry for immunoglobulin G (IgG) and IgG4 has been shown in a subset of patients, suggesting a possible autoimmune factor in some patients.[22] This finding warrants further study.
Treatment
Approach Considerations
Conservative therapy (ie, warm sitz baths, topical estrogen creams, topical anti-inflammatory drugs) is appropriate in most patients. Surgical intervention should be reserved for patients with larger symptomatic lesions, for those in whom conservative therapy fails to elicit a response, and for those with uncertain diagnoses.
Medical Care
Most urethral caruncles can be treated conservatively with warm sitz baths and vaginal estrogen replacement. Topical anti-inflammatory drugs may also be useful. Unfortunately, data on the efficacy of conservative management are lacking in the literature. In fact, a review of current literature completed in 2020 was unable to find any published systematic studies on the conservative management of urethral caruncles.[23]
Nevertheless, anecdotal experience indicates that vaginal estrogen replacement is effective for many cases. Patients may notice symptomatic improvement within 6 weeks, but maximal effect of vaginal estrogen therapy is in 3 to 6 months.
Surgical Care
Reserve surgical intervention for patients with larger symptomatic lesions and for those with uncertain diagnoses. Tumors are found in approximately 2% of urethral caruncles.[13] Possible indications for excisional biopsy include the following:
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Induration
-
Failure to respond to conservative therapy
-
Atypical appearance
-
Growth over time
Cystourethroscopy should be performed if surgical excision is undertaken, to exclude bladder and urethral abnormalities. Many urologists perform a cystoscopy in the office upon initial patient presentation to rule out other pathologies (eg, carcinoma, diverticulum, abscess).
Preoperative Details
Standard vaginal preparation and preoperative antibiotics are recommended.
Intraoperative Details
Excision is usually an outpatient operation and involves the following steps:
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Place a Foley catheter
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Use stay-sutures in the epithelium to prevent mucosal retraction and meatal stenosis
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Excise the lesion
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Oversew the edges with 3-0 or 4-0 absorbable sutures (chromic or polyglactin)
Park and Cho have described an alternative technique for removal of a urethral caruncle whereby the base of the caruncle is ligated, allowing it to slough off after 1-2 weeks.[24] Their technique requires neither anesthesia nor analgesics.
Postoperative Details
Following surgical excision, ensure patient can void adequately. If the patient is unable to void postoperatively or the surgery involved extensive excision, a Foley catheter may be left in place for 1-2 days to allow for appropriate healing of the urethral mucosa.
Complications
If the epithelium is not everted adequately with the stay-stitch, meatal retraction and stenosis may occur.
Long-Term Monitoring
If the lesion is benign, no special follow-up is required. However, patients who developed caruncles secondary to genitourinary syndrome of menopause should remain on vaginal estrogen to prevent new occurrences.
Medication
Medication Summary
Vaginal estrogen replacement may be considered to treat urogenital atrophy secondary to estrogen deficiency in postmenopausal women.
Intravaginal Estrogen
Class Summary
Use of intravaginal estrogens help to maintain female urogenital elasticity and treats vulvovaginal atrophy. Estrogens increase cervical secretions and increase uterine tone.
Estradiol vaginal (Estrace Vaginal, Vagifem, Yuvafem)
Doses and recommended treatment duration for specific products vary. Creams or vaginal inserts are typically administered once daily for 1-2 weeks, followed by a reduced dose and a maintenance dose of 2-3 times weekly.
Questions & Answers
Overview
How are urethral caruncles characterized?
What is the anatomy of the female urethra relevant to urethral caruncles?
What is the pathophysiology of urethral caruncles?
What is the prevalence of urethral caruncles?
What is the prognosis of urethral caruncles?
Presentation
What are the signs and symptoms of urethral caruncles?
Which physical findings are characteristic of urethral caruncles?
DDX
Which conditions are included in the differential diagnoses of urethral caruncle?
What are the differential diagnoses for Urethral Caruncle?
Workup
What is the role of lab tests in the workup of urethral caruncles?
What is the role of biopsy in the workup of urethral caruncles?
What is the role of cystoscopy in the workup of urethral caruncles?
Which histologic findings are characteristic of urethral caruncles?
Treatment
How are urethral caruncles treated?
What is included in conservative treatment of urethral caruncles?
What are the surgical indications for urethral caruncles?
What is included in the preoperative care of urethral caruncles prior to excision?
How are urethral caruncles excised?
What is included in postoperative care following excision of urethral caruncles?
What are the possible complications of urethral caruncles excision?
What is included in the long-term monitoring of patients with urethral caruncles?
Medications
What is the role of medications in the treatment of urethral caruncles?