Introduction

Urethral prolapse (UP) is a circular eversion of the urethral mucosa through the urethral meatus in women. It was first described in 1732 by Solinger and is an uncommon condition that affects mainly black prepubertal girls and postmenopausal women [1]. As the majority of UPs occur in the pediatric age group [2], there are few reports in adults. Diagnosis is essentially clinical, by observation of a doughnut-shaped mass protruding from the urethra. As an uncommon condition, UP is often misdiagnosed initially, sometimes even in the pediatric population [3]. Descriptive studies of its occurrence in the adult population are thus warranted in order to draw attention for this simple, readily diagnosed condition. UP is usually asymptomatic, especially in children; when manifestations are present, blood in the underwear is the most common chief complaint. Treatment may be surgical or conservative, although this is a point of contention [4]. There are no large series and no studies comparing different treatment approaches in adulthood. Etiology is also unclear; one of the proposed hypotheses is estrogen deficiency, which would justify the bimodal age distribution [1, 2, 5,6,7]. Our aim is to discuss this condition and report our experience with 12 adult patients, including one case in a woman of childbearing age, a population group in which this condition is extremely rare [2, 5].

Patients and Methods

After ethics committee approval, we reviewed the medical records of all cases diagnosed as urethral mucosal prolapse and treated at our outpatient micturition disorders clinic between August 2014 and April 2017. Age, skin color, body mass index (BMI), reason for referral, symptoms, risk factors that may contribute to the development of UP, diagnosis made at our department, treatment, outcome, and additional relevant information were obtained from medical records. For those patients whose cases were documented photographically, relevant images were included in this publication after obtaining specific written consent.

Results

A review of records of our outpatient adult micturition disorders clinic yielded 12 cases of UP, all treated successfully. These included one case of a small but highly symptomatic urethral mucosal prolapse in a 21-year-old patient (case 6, Fig. 1), which was successfully treated with topical estrogen [2, 8, 9]; a mother and daughter who presented simultaneously, both with UP; and several cases with complications, including urinary retention, bleeding, and thrombosis of the prolapsed urethral mucosa (Table 1). Correct diagnosis was rarely established before referral to our clinic (Table 1).

Fig. 1
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a Case number 12, b case number 6: reproductive-aged patient with a small urethral mucosal prolapse, c, d highly symptomatic small partial urethral mucosal eversion in two reproductive-aged patients

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Table 1 Description of the cases, treatment, and outcomes
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Discussion

Urethral prolapse occurs when the distal urethral mucosa protrudes through the external meatus. The diagnosis is based essentially on by clinical findings on physical examination, which reveals an anterior vulvar bulk of soft, friable tissue, with the urethral meatus usually in the center (a “doughnut”-shaped mass). In symptomatic cases, vaginal bleeding is the most common complaint; however, hematuria, dysuria, frequency, urgency, nocturia, pain, dyspareunia, and urinary retention are other potential presenting symptoms. Imaging is usually unnecessary and should be ordered only if another condition or infection is suspected [2]. All cases in our series were promptly recognized by our staff as urethral mucosal prolapse, despite very different presentations, including trips to the emergency room with acute complications or during routine appointments in the clinic.

UP is an uncommon condition, occurring more frequently in prepubertal girls and postmenopausal women; the possibility should always be considered when evaluating a periurethral lesion in these patients. The differential diagnosis includes neoplasm (vaginal rhabdomyosarcoma, urethral carcinoma or papilloma); urethral caruncle, polyp, or diverticulum; Skene’s cyst; abscess; HPV; prolapsing ureterocele; imperforate hymen; and sexual abuse [10].

In our cases, three patients were treated for more than a year on the basis of an incorrect diagnosis of urethral caruncle, without resolution. One can argue that the conservative treatment with topic estrogen is the same for both conditions, but resolution was nevertheless considerably delayed in the presence of major symptoms.

The pathophysiology of UP remains uncertain. The main etiologic hypothesis is estrogen deficiency, because of the preponderance of UP in the prepubertal and postmenopausal periods. Postpartum, there is a mild estrogen deficiency, which may explain the rare cases that occur in this period [9]. Other contributing factors include high intra-abdominal pressure, perineal or urethral trauma (including catheterization), injection of bulking agents, sexual abuse, and infection [7]. One case in our series occurred in the early postoperative period (case 8), consistent with surgical pelvic trauma or pelvic prolapse reduction provoking urethral prolapse. Two cases (patients 5 and 11) were consistent with acute elevation of intra-abdominal pressure, both presenting with acute onset (or new perception) of vaginal mass. As expected, all but one of our cases were postmenopausal.

In 1986, Lowe studied the histopathology of UP and observed a cleavage plane between the inner longitudinal and outer circular-oblique smooth muscle layers of the urethra, as well as marked mucosal eversion and vascular congestion [6, 10]. Another possible risk factor could be a malformation or weak collagen structures, since many patients report a family history of hernias and vaginal prolapses. In our series, we observed this association in two of our cases—a mother and daughter who presented with UP simultaneously. However, additional research of larger samples is needed to study the role of familiar inheritance.

UP can be complicated or uncomplicated and partial or total. It is complicated when there is vascular thrombosis of the mucosa, significant bleeding, pain, infection, or urinary retention. Almost all of these complications were represented in our series, as described in Table 1 and illustrated in Figs. 1 and 2, suggesting that these complications are not uncommon and that prompt recognition and treatment of UP are important to prevent them. Otherwise, the most common presentation is uncomplicated prolapse, which can be fully asymptomatic or present with minor bleeding or mild pain. The theory is that UP begins as a partial prolapse and becomes complete (circumferential), since in many cases a complete prolapse becomes partial with conservative measures and an untreated partial prolapse can become complete. There were some cases in our clinic of minor partial extrusion of the urethral mucosa through the meatus (Fig. 1), causing discomfort; these occurred in patients of childbearing age and were successfully treated with topical estrogen. This clinical picture has rarely been described in the literature, but in our clinic it was rather common and very symptomatic.

Fig. 2
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a Case number 1, b case number 3, c case number 10, d case number 9 at the start of surgery

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Treatment of UP is controversial and can be surgical or conservative. The nonsurgical approach consists basically of sitz bath and topical estrogen cream for approximately 6 weeks; we usually recommend it for mild or asymptomatic cases [8, 10, 11]. As urinary infection is rare, antibiotics are unnecessary. Topical steroids are ineffective. The success of nonsurgical treatment is variable, ranging from 33 to 92%, and appears to be more effective in prepubertal girls than in postmenopausal women [10]. In some cases, spontaneous resolution may occur. The recurrence rate with conservative management is up to 67%, while surgery is associated with higher cure rates and rapid relief of symptoms [5].

In our series, all postmenopausal patients were treated surgically with good outcomes. There are many surgical options, all of which include resection of the prolapsed mucosa (over a Foley catheter or not) and suture of the urethral mucosa to the meatus. We used the modified Kelly–Burnham (or four-quadrant excisional) technique, which involves placing four stitches in four quadrants of prolapsed mucosa, incising each quadrant between the holding sutures up to the mucocutaneous junction, without a Foley catheter, followed by immediate approximation of the mucocutaneous junction with absorbable sutures [7, 10]. Another option is manual prolapse reduction under general anesthetic, but this is associated with a risk of only partial reduction of 62% and recurrence of 12% in children. This technique has not been studied in adults [12]. In one case in our series, we performed manual reduction in the emergency room, but recurrence occurred after only a few hours; hence, we decided to perform surgery (Fig. 3). Some authors argue that slings can be effective to treat UP [13]. We have used slings in combination with UP excision with good results, but only in cases where there was comorbid stress urinary incontinence; additional research is needed to study the impact of this approach in other situations.

Fig. 3
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All images are from case 11. a Before surgery, b prolapse reduced in the emergency room, c two-month postoperative follow-up after topical estrogen replacement, d three years after surgery, a urethral caruncle developed

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Therefore, we believe that management should be individualized, with the conservative approach selected for asymptomatic or mild cases and surgical excision for complicated or very symptomatic patients.

In short, UP is an underdiagnosed entity not only due to its rarity, but also to the unfamiliarity of clinicians—even specialists—with this condition. Complications are not uncommon, and although UP should be readily recognized by clinical examination alone, correct diagnosis is the main determining factor of timely treatment and resolution of symptoms. We hope this descriptive study can raise awareness of this diagnosis in the adult population and improve the care of these patients.