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
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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.
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This image shows marked vascular engorgement and a polymorphous inflammatory infiltrate in the stroma. Surface epithelium is benign. Courtesy of GT MacLennan, MD.
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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.
