Urethral Caruncle

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Background

Urethral caruncles are benign, distal urethral lesions that are most commonly found in postmenopausal women, although a case of urethral caruncle has also been described in a male.[1] Urethral caruncles resemble various urethral lesions, including carcinoma. The differential diagnoses of urethral caruncle include the following:

Most urethral caruncles 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:

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.

Epidemiology

Frequency

Urethral caruncles are common in elderly postmenopausal women but are rare in premenopausal or perimenopausal women.[2] Urethral prolapse is similar in appearance, 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.

Etiology

Urethral caruncles may develop from several simultaneous processes, as discussed in the Pathophysiology section.

Pathophysiology

The first step in the development of a urethral caruncle is likely distal urethral prolapse caused by urogenital atrophy due to estrogen deficiency. Chronic irritation, where the urethral mucosa is exposed, contributes to the growth, hemorrhage, and necrosis of the lesion.

Cases of urethral melanoma,[3] tuberculosis,[4, 5] intestinal ectopia, lymphoma,[6, 7] and urethral leiomyoma[8] masquerading as urethral caruncle have been reported; however, reports of these associations are rare. Intraepithelial squamous cell carcinoma arising within a urethral caruncle has been reported in two patients.[9] Additionally, urethral caruncles have been reported to occur rarely in the premenopausal patient and may enlarge during pregnancy. Urethral polyps are the pediatric equivalent of urethral caruncles and manifest in a similar fashion.

Presentation

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.

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.[10] Isolated case reports of urinary retention from urethral caruncle do exist, however.[11]

On examination, caruncles most often appear clinically as a pink or reddish exophytic lesion at the urethral meatus; in rare cases, they are purple or black secondary to thrombosis. Some caruncular lesions may resemble urethral carcinoma.

Indications

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.

Relevant Anatomy

The female urethra is a 4- to 5-cm tubular structure. 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.

Contraindications

Surgical therapy should be reserved for women with larger symptomatic lesions and for women with uncertain diagnoses.

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.

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).



View Image

This image shows marked vascular engorgement and a polymorphous inflammatory infiltrate in the stroma. Surface epithelium is benign. Courtesy of G.T. ....

A pathology series of 41 patients demonstrated mixed hyperplastic urothelial or squamous lining.[12] 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.[13] This finding warrants further study.

Medical Therapy

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.

Surgical Therapy

Reserve surgical intervention for patients with larger symptomatic lesions and for those with uncertain diagnoses. Induration, failure to respond to conservative therapy, atypical appearance, or growth over time may be indications for excisional biopsy. Tumors are found in approximately 2% of urethral caruncles.

Preoperative Details

Standard vaginal preparation and preoperative antibiotics are recommended.

Intraoperative Details

Excision is usually an outpatient operation and involves the following steps:

Postoperative Details

A Foley catheter may be left in place for 1-2 days to allow for appropriate healing of the urethral mucosa.

Follow-up

If the lesion is benign, no special follow-up is required.

Complications

If the epithelium is not everted adequately with the stay-stitch, meatal retraction and stenosis may occur.

Outcome and Prognosis

The prognosis is excellent if pathology confirms urethral caruncle as the diagnosis.

Future and Controversies

Urethral caruncle management is straightforward. As the etiology of these lesions is better elucidated, improvements in medical therapies may obviate surgery.

Author

Kamran P Sajadi, MD, Assistant Professor, Urology, Oregon Health & Science University

Disclosure: Nothing to disclose.

Specialty Editors

Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Mark Jeffrey Noble, MD, Consulting Staff, Urologic Institute, Cleveland Clinic Foundation

Disclosure: Nothing to disclose.

Chief Editor

Edward David Kim, MD, FACS, Professor of Surgery, Division of Urology, University of Tennessee Graduate School of Medicine; Consulting Staff, University of Tennessee Medical Center

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Repros.

Additional Contributors

Allen Donald Seftel, MD, Professor of Urology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School; Head, Division of Urology, Director, Urology Residency Training Program, Cooper University Hospital

Disclosure: Received consulting fee from lilly for consulting; Received consulting fee from abbott for consulting; Received consulting fee from auxilium for consulting; Received consulting fee from actient for consulting; Received honoraria from journal of urology for board membership; Received consulting fee from endo for consulting.

Acknowledgements

Ann Y Becker, MD Assistant Professor, Section of Urology, Medical College of Georgia

Ann Y Becker, MD is a member of the following medical societies: American Medical Women's Association, American Urological Association, and Society of Women in Urology

Disclosure: Nothing to disclose.

Scott Rutchik, MD Assistant Professor, Department of Surgery, Division of Urology, University of Connecticut School of Medicine

Scott Rutchik, MD is a member of the following medical societies: American Urological Association

Disclosure: Nothing to disclose.

References

  1. Karthikeyan K, Kaviarasan PK, Thappa DM. Urethral caruncle in a male: a case report. J Eur Acad Dermatol Venereol. 2002 Jan. 16(1):72-3. [View Abstract]
  2. Chiba M, Toki A, Sugiyama A, Suganuma R, Osawa S, Ishii R, et al. Urethral caruncle in a 9-year-old girl: a case report and review of the literature. J Med Case Rep. 2015 Mar 28. 9:71. [View Abstract]
  3. Nakamoto T, Inoue Y, Ueki T, Niimi N, Iwasaki Y. Primary amelanotic malignant melanoma of the female urethra. Int J Urol. 2007 Feb. 14(2):153-5. [View Abstract]
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This image shows marked vascular engorgement and a polymorphous inflammatory infiltrate in the stroma. Surface epithelium is benign. Courtesy of G.T. MacLennan, MD.

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