A urethral caruncle is a small, benign growth that forms on the outside opening of the urethra, the tube that carries urine out of the body. This lesion affects the distal urethral mucosa, the soft inner lining. Urethral caruncles are the most common benign tumor affecting the female urethra and occur most frequently in women who have gone through menopause.
What a Urethral Caruncle Looks Like
A urethral caruncle typically presents as a soft, fleshy lump situated at the opening of the urethra, an area known as the meatus. It is usually found on the posterior lip, meaning it protrudes from the back part of the urethral opening. The growth is highly vascular, giving it a characteristic bright red, dark pink, or reddish-purple color.
The size of a caruncle is usually small, often measuring less than 1 to 2 centimeters in diameter. These growths can be either sessile, meaning they have a broad base, or pedunculated, appearing on a stalk like a tiny raspberry. If a blood clot forms within the caruncle, its color can darken to purple or even black.
While many urethral caruncles cause no noticeable symptoms and are only found during a routine medical examination, they can become symptomatic. Due to their fragile, highly vascular nature, they may bleed easily, especially when wiped or during light friction. Other symptoms can include localized pain, a burning sensation during urination known as dysuria, or blood in the urine, called hematuria.
A caruncle protrudes on only one edge of the opening, which helps distinguish it from a urethral prolapse, where the entire inner lining of the urethra bulges out in a donut shape.
Reasons for Urethral Caruncle Formation
The primary factor driving the development of a urethral caruncle is the decline in estrogen levels, which occurs most notably after menopause. Estrogen plays a protective role by maintaining the thickness, elasticity, and overall health of the tissues in the genital and urinary areas. When this hormone decreases, the urethral lining becomes thinner and less supported, a condition known as urogenital atrophy.
This thinning of the urethral mucosa makes the tissue more susceptible to injury and irritation. The lack of support from surrounding smooth muscle can also make the inner lining of the urethra more likely to bulge outward, which may lead to caruncle formation. The condition is overwhelmingly prevalent in postmenopausal women, although rare cases can be seen in premenopausal women and young girls.
Chronic irritation and inflammation are also thought to contribute to the development of these growths. This irritation can come from minor trauma, such as friction, or from exposure to certain chemicals in hygiene products.
Diagnosis and Treatment Protocols
Diagnosis of a urethral caruncle usually begins with a simple clinical evaluation and physical examination. A healthcare provider can often identify the growth visually based on its characteristic appearance, location, and texture. However, the main challenge in diagnosis is the need to rule out other, potentially more serious lesions that can look similar, such as urethral cancer, urethral melanoma, or urethral prolapse.
A biopsy is typically reserved for lesions that exhibit atypical characteristics or fail to respond to initial conservative treatment. This step ensures that the growth is definitively benign, as a small percentage of lesions that look like caruncles have been found to contain cancerous cells. Other investigations, such as a cystoscopy, may be performed to assess the inside of the urethra and bladder if symptoms like bleeding are present or if the diagnosis remains uncertain.
For most patients, especially those who are asymptomatic or have only mild discomfort, the initial approach to management is conservative. This often includes observation and the use of topical estrogen cream, which helps restore the health and thickness of the urethral tissue. Topical anti-inflammatory drugs or warm sitz baths may also be recommended to alleviate discomfort and irritation.
If the caruncle is large, causes significant pain, leads to frequent bleeding, or interferes with urination, surgical removal may be necessary. Surgical options typically involve simple excision or techniques like electrofulguration, which uses an electrical current to destroy the tissue. The prognosis for a urethral caruncle is excellent once more serious conditions have been excluded, and recurrence after successful treatment is relatively low.