Developing and validating a simple urethra surrogate model to facilitate dosimetric analysis to predict genitourinary toxicity.

Purpose: The urethra is a critical structure in prostate radiotherapy planning; however, it is impossible to visualise on CT. We developed a surrogate urethra model (SUM) for CT-only planning workflow and tested its geometric and dosimetric performance against the MRI-delineated urethra (MDU). Methods: The SUM was compared against 34 different MDUs (within the treatment PTV) in patients treated with 36.25Gy (PTV)/40Gy (CTV) in 5 fractions as part of the PACE-B trial. To assess the surrogate's geometric performance, the Dice similarity coefficient (DSC), Hausdorff distance (HD), mean distance to agreement (MDTA) and the percentage of MDU outside the surrogate (UOS) were calculated. To evaluate the dosimetric performance, a paired t-test was used to calculate the mean of differences between the MDU and SUM for the D99, D98, D50, D2 and D1. The D(n) is the dose (Gy) to n% of the urethra. Results: The median results showed low agreement on DSC (0.32; IQR 0.21-0.41), but low distance to agreement, as would be expected for a small structure (HD 8.4mm (IQR 7.1-10.1mm), MDTA 2.4mm (IQR, 2.2mm-3.2mm)). The UOS was 30% (IQR, 18-54%), indicating nearly a third of the urethra lay outside of the surrogate. However, when comparing urethral dose between the MDU and SUM, the mean of differences for D99, D98 and D95 were 0.12Gy (p=0.57), 0.09Gy (p=0.61), and 0.11Gy (p=0.46) respectively. The mean of differences between the D50, D2 and D1 were 0.08Gy (p=0.04), 0.09Gy (p=0.02) and 0.1Gy (p=0.01) respectively, indicating good dosimetric agreement between MDU and SUM. Conclusion: While there were geometric differences between the MDU and SUM, there was no clinically significant difference between urethral dose-volume parameters. This surrogate model could be validated in a larger cohort and then used to estimate the urethral dose on CT planning scans in those without an MRI planning scan or urinary catheter.

Primary mucinous adenocarcinoma of the urethra: A contemporary clinicopathologic analysis of 17 patients.

Mucinous adenocarcinoma of the urethra is rare. Here we performed a contemporary clinicopathologic analysis of this entity in both male and female patients. All cases with secondary tumors involving the urethra were excluded. Clinicopathologic parameters and follow up was obtained. Seventeen patients were included in the study, 9/17 (53 %) male and 8/17 (47 %) female. The mean patient age was 68 years (range: 53-88 years). The majority (11/17, 65 %) of patients were African American, with an even greater incidence (7/8, 87 %) in female patients. In male patients, prostatic urethra was the most common part of the urethra (6/9, 67 %) where the tumor arose from. Immunohistochemical stains were performed in 11/17 (65 %) tumors and were positive for CK20 (11/11, 100 %), CDX2 (11/12, 92 %), CK7 (8/9, 88 %), GATA3 (3/8, 37 %) and negative for NKX3.1, PSA, p63, PAX8, and Beta-Catenin. In resection specimens, tumors were categorized as pT2 (3/11, 27 %), pT3 (1/11, 9 %), and pT4 (7/11, 64 %). Lymph node status was categorized as pN0 (6/9, 67 %), pN1 (1/9, 11 %), and pN2 (2/9, 22 %). Available follow up data showed 7/13 (54 %) patients developed recurrence after surgical resection and chemotherapy, of which 3/7 (43 %) died of widespread metastatic disease. It is critical for pathologists and urologic oncologists to be aware of this entity in both male and female patients in view of potential diagnostic pitfalls, prognosis, and therapeutic implications.

Symmetric dimethylarginine correlates with the urea, creatinine, potassium, and clinical scores in feline urethral obstructions.

BACKGROUND: A urethral obstruction (UO) is an emergency commonly observed in male cats, which can result in significant clinical and laboratory alterations, leading to complications and death. OBJECTIVES: This study aimed to correlate symmetric dimethylarginine (SDMA) with the urea, creatinine, potassium, and bicarbonate levels in cats with UO. In addition, the correlation between clinical score and time of obstruction was evaluated. METHODS: Thirty male cats were selected and allocated into a control group (CG, n = 13) and an obstruction group (OG, n = 17). The laboratory analyses were conducted before treatment (M0) and at different times after treatment (12 h [M12], 24 h [M24], and 48 h [M48]). Correlations were established between SDMA and creatinine, urea, bicarbonate, potassium, time of obstruction, and the clinical score. RESULTS: A strong correlation (r > 0.6) was observed between SDMA and creatinine, urea, and potassium in the OG. Furthermore, there was substantial agreement (kappa value) between SDMA and creatinine at M24. A higher clinical score was associated with a longer time of obstruction. In the OG, at M48, the SDMA and creatinine levels were 50% and 41.2% higher, respectively. CONCLUSIONS: A correlation was observed between SDMA and creatinine in obstructed cats, and significant agreement between these values was observed 24 h after the unblocking treatment. A correlation among SDMA, urea, and potassium was observed. Approximately 9% more cats continued to have elevated SDMA levels after 48 h of treatment compared to creatinine. This suggests a slightly lower sensitivity of the latter biomarker but does not exclude the possibility of congruent and normalized values after a longer evaluation period.

Successful surgical excision of the accessory urethra in a 13-year-old boy with Effmann Type IIA-2 urethral duplication. Case report and literature review.

INTRODUCTION AND CLINICAL IMPORTANCE: Urethral duplication is a congenital anomaly characterized by the partial or full development of an auxiliary urethra as a second urethral channel varying in extent and location. The course of treatment for urethral duplication should be individualized for each patient based on the type of anomaly and the existence of symptoms. In most cases, if the ventral orthotopic urethra is normal, excision of the dorsal auxiliary urethra is almost always curative. CASE PRESENTATION: We report a case of a 13-year-old boy who presented with recurrent urinary tract infection, occasionally having drops of urine at an external pin hole meatal opening on the dorsum of the penile shaft. Several investigations were performed to confirm the presence of the dorsal accessory urethra. The patient underwent complete excision of the accessory urethra, and 12 weeks post-surgery the patient was completely asymptomatic. DISCUSSION: Urethral duplications are rare anomalies. These anomalies have been classified in various ways in the literature, including sagittal and lateral duplications, dorsal and ventral duplications. The sagittal plane is where the majority of urethral duplications occur. Based on the anatomic variation, clinical presentation and severity of the anomaly, urethral duplication treatment should be customized for each patient. An asymptomatic child may require no specific treatment. Total surgical excision of the dorsal accessory urethra appears to offer the best curative solution. CONCLUSION: Excision of the dorsal accessory urethra is usually curative when the ventral orthotopic urethra is normal. Thorough investigation before surgery is mandatory to determine the type of urethral duplication. The most common diagnostic procedures for urethral duplications include cystoscopy, KUB ultrasonography, and micturating cystourethrography. These procedures can help plan surgery, prevent complications such as neurovascular bundle injuries and urine incontinence, and improve patient self-esteem and quality of life.

Nitrergic inhibition of sympathetic arteriolar constrictions in the female rodent urethra.

During the urine storage phase, tonically contracting urethral musculature would have a higher energy consumption than bladder muscle that develops phasic contractions. However, ischaemic dysfunction is less prevalent in the urethra than in the bladder, suggesting that urethral vasculature has intrinsic properties ensuring an adequate blood supply. Diameter changes in rat or mouse urethral arterioles were measured using a video-tracking system. Intercellular Ca2+ dynamics in arteriolar smooth muscle (SMCs) and endothelial cells were visualised using NG2- and parvalbumin-GCaMP6 mice, respectively. Fluorescence immunohistochemistry was used to visualise the perivascular innervation. In rat urethral arterioles, sympathetic vasoconstrictions were predominantly suppressed by α,ß-methylene ATP (10 µM) but not prazosin (1 µM). Tadalafil (100 nM), a PDE5 inhibitor, diminished the vasoconstrictions in a manner reversed by N-ω-propyl-l-arginine hydrochloride (l-NPA, 1 µM), a neuronal NO synthesis (nNOS) inhibitor. Vesicular acetylcholine transporter immunoreactive perivascular nerve fibres co-expressing nNOS were intertwined with tyrosine hydroxylase immunoreactive sympathetic nerve fibres. In phenylephrine (1 µM) pre-constricted rat or mouse urethral arterioles, nerve-evoked vasodilatations or transient SMC Ca2+ reductions were largely diminished by l-nitroarginine (l-NA, 10 µM), a broad-spectrum NOS inhibitor, but not by l-NPA. The CGRP receptor antagonist BIBN-4096 (1 µM) shortened the vasodilatory responses, while atropine (1 µM) abolished the l-NA-resistant transient vasodilatory responses. Nerve-evoked endothelial Ca2+ transients were abolished by atropine plus guanethidine (10 µM), indicating its neurotransmitter origin and absence of non-adrenergic non-cholinergic endothelial NO release. In urethral arterioles, NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions pre- and post-synaptically to restrict arteriolar contractility. KEY POINTS: Despite a higher energy consumption of the urethral musculature than the bladder detrusor muscle, ischaemic dysfunction of the urethra is less prevalent than that of the bladder. In the urethral arterioles, sympathetic vasoconstrictions are predominately mediated by ATP, not noradrenaline. NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions by its pre-synaptic inhibition of sympathetic transmission as well as post-synaptic arteriolar smooth muscle relaxation. Acetylcholine released from parasympathetic nerves contributes to endothelium-dependent, transient vasodilatations, while CGRP released from sensory nerves prolongs NO-mediated vasodilatations. PDE5 inhibitors could be beneficial to maintain and/or improve urethral blood supply and in turn the volume and contractility of urethral musculature.

Ultrasound for the evaluation of the urethra in pediatric patients.

Urethral lesions in pediatric patients can be visualized using ultrasonography. Therefore, sonographers and physicians should be familiar with the technique.

An assessment of the relationship between urethral hypermobility as measured by ultrasound and the symptoms of stress urinary incontinence in primiparous women 9-18 months postpartum.

Aim: The aim of the study was to estimate the relationship between bladder neck hypermobility as assessed by ultrasound and the occurrence of stress urinary incontinence as measured with the UDI-6 questionnaire in primiparous women 9-18 months postpartum. Materials and methods: The study included 100 women 9-18 months after their first delivery, 19% of whom (study group) presented with urethral hypermobility. Ultrasound was used to determine the position and mobility of the bladder neck in order to assess the urethral hypermobility. A vector of ≥15 mm was defined as urethral hypermobility. Symptoms of stress urinary incontinence were assessed using question 3 of the UDI-6 questionnaire, in which the presence of symptoms was defined as a response rated from 1 to 4. Results: We demonstrated a statistically significant relationship between urethral hypermobility and the symptoms of stress urinary incontinence with a statistical significance level of p <0.002. Conclusions: Stress urinary incontinence is a common disorder in women, the pathophysiology of which is not fully understood. It has adverse effects on the quality of life, perception of one's own body and sexual function. Impairment of urethral fixation may play an important role in the pathophysiology of this common form of urinary incontinence. The study showed that urethral hypermobility, as assessed by ultrasound, contributes to stress urinary incontinence, as measured with the UDI-6 score. Although stress urinary incontinence is a multifactorial disorder influenced by anatomical changes and congenital anatomical features, it is easily diagnosed. Suburethral slings are an effective surgical technique; however, the incidence of postoperative voiding dysfunction or recurrent stress urinary incontinence is 10-20%. Therefore, an assessment of anatomical changes in stress urinary incontinence may help individualize the surgical strategy.

Primary urethral carcinoma: Recommendations of the oncology committee of the French Urology Association.

Primary urethral carcinoma (PUC) is defined as a tumor process arising within the urethra, with no history of other urinary tract localization or synchronous tumor of the urinary tract. The most common histological types are urothelial carcinoma (UC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). In men, UC predominates, while AC is rare. In women, AC affects around one in two patients, while EC and UC are equally divided between the remaining cases. Diagnosis is often delayed, and requires endoscopic examination with biopsies. MRI is the gold standard for local staging. FDG-PET scan can help in cases of doubt about regional or distant extension. The prognosis remains unfavorable despite aggressive surgical treatment. Multimodal management combining surgery, radiotherapy and chemotherapy appears to improve prognosis in severe forms.

Post catheterization Fournier's gangrene involving the entire anterior urethra: case report.

INTRODUCTION AND IMPORTANCE: Fournier's gangrene is necrotizing fasciitis involving the penis, scrotum, or perineal region. This is to report necrosis of the entire anterior urethra by necrotizing infection even though the involvement of the urethra by Fournier's is a very rare presentation. A high index of suspicion is important for early intervention. The main Mode of treatment for Fournier's gangrene is debridement. CASE PRESENTATION: This is a case report for a 58-year-old male patient who presented with penile and scrotal swelling after he was catheterized with NG tube for acute urinary retention. The physical finding shows swollen scrotum with ulcerated necrotic glans penis anteriorly. Laboratory result shows leukocytosis and urine analysis is positive for urinary tract infection and ultrasound shows bladder diverticula with normal prostate volume. He underwent debridement up to the level of membranous urethra and suprapubic catheterization was done. He was treated with antibiotics and wound care and finally, the wound closed. Post-operative cystourethrography was done 9 months later and we offered staged urethroplasty but he decided for permanent SPC. DISCUSSION: Fournier's gangrene is a fatal rapidly spreading infection that occurs in the perineal area. Involvement of urethra by necrotizing infection following catheterization is very rare presentation and diagnosis is mostly clinical. Once it is diagnosed the management is surgical debridement. CONCLUSION: Fournier's gangrene with urethral involvement is a very rare presentation and a high index of suspicion is important for early diagnosis and management. Following the standard procedural steps of catheterization is important to avoid this complication.

Anatomy of muscle connections in the male urethra and anorectal canal.

OBJECTIVES: To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence. METHODS: Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D. RESULTS: The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter. CONCLUSION: This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.

Florid Cystitis Glandularis with Intestinal Metaplasia in the Prostatic Urethra: a case report and review of the literature.

INTRODUCTION: Cystitis glandularis is a proliferative disease of the bladder epithelium usually presenting in the setting of chronic inflammation, characterized by the formation of glands in the bladder mucosa and submucosa. Intestinal metaplasia is a described process in cystitis glandularis characterized by the presence of intestinal cells and mucin production which is rare as compared to cystitis glandularis. CASE PRESENTATION: We present a case of cystitis glandularis with intestinal metaplasia located in the bladder and concomitantly in the prostatic urethra. Patient underwent transurethral resection of the lesion which was unusually found in the prostatic urethra. CLINICAL DISCUSSION: Florid cystitis glandularis is a rare condition found in women more than in men. It usually presents with irritative lower urinary tract symptoms or hematuria which leads to its eventual diagnosis. It is usually causes by inflammation to the bladder mucosa due to infections or irritation. Patients are diagnosed through Transurethral resection of these bladder lesions found in the trigone and bladder neck region. Surgery is the standard treatment of choice. However, medical treatment may also be used to treat underlying inflammatory conditions using antibiotics, steroids, and non-steroidal anti-inflammatory agents. Radical or partial cystectomy may be performed for severe refractory cases. CONCLUSION: This article describes the rare occurrence of florid cystitis glandularis in the prostatic urethra and provides an overview on diagnosis, etiology, and management of the disease.

ONE SHOT - single shot radiotherapy for localized prostate cancer: 18-month results of a single arm, multicenter phase I/II trial.

PURPOSE: To assess in a prospective, multicenter, single-arm phase I/II study the early safety and efficacy profile of single fraction urethra-sparing stereotactic body radiotherapy (SBRT) for men with localized prostate cancer. MATERIAL AND METHODS: Patients with low- and intermediate-risk localized prostate cancer without significant tumor in the transitional zone were recruited. A single-fraction of 19 Gy was delivered to the prostate, with 17 Gy dose-reduction to the urethra. Intrafraction motion was monitored using intraprostatic electromagnetic transponders with intra-fraction correction of displacements exceeding 3 mm. Genitourinary (GU), gastrointestinal (GI), and sexual toxicity during the first 18 months were evaluated using the CTCAE v4.0 grading scale. Quality of life was assessed using the International Prostate Symptom Score, the Expanded Prostate Cancer Index composite 26 score, and the International Index of Erectile Function score. RESULTS: Among the 45 patients recruited in 5 centers between 2017 and 2022, 43 received the single fraction without protocol deviations, and 34 had a minimal follow-up of 18 months. The worst GU toxicity was observed at day-5 after SBRT (42.5 % and 20 % with grade 1 and 2, respectively), returning to baseline at week-12 and month-6 (<3% with grade 2), with a 12 % grade 2 flare at month 18. Gl toxicity was mild in the acute phase, with no grade ≥ 2 events (12 % grade 1 at month 6). Grade-3 proctitis was observed in one patient at month 12, with < 3 % grade 2 toxicity at month 18. Mean GU and GI bother scores showed a decline at day 5, a complete recovery at month 6, and a flare between month 12 and 18. Mean PSA dropped from 6.2 ng/ml to 1.2 ng/ml at month 18 and 0.7 ng/ml at month 24. After a median follow-up time of 26 months, 3 biochemical failures (7 %) were observed at month 17, 21 and 30. CONCLUSIONS: In this multicenter phase I/II trial, we demonstrated that a 19 Gy single-fraction urethra-sparing SBRT is feasible and associated with an acceptable toxicity rate, mostly returning to the baseline at week-12 and with a symptoms flare between months 12 and 18. Longer follow-up is needed to assess the potential long-term adverse effects and the disease control efficacy.

New uses for an old technique: live imaging on the slice organ culture to study reproductive processes.

Reproductive processes are dynamic and involve extensive morphological remodeling and cell-cell interactions. Live imaging of organs enhances our understanding of how biological processes occur in real time. Slice culture is a type of organ culture where thick slices are collected from an organ and cultured for several days. Slice culture is a useful and easy-to-implement technique for live imaging of reproductive events at cellular resolution. Here we describe a pipeline of live imaging on slice culture to visualize the process of urethra closure in mouse embryonic penis as a proof of principle. In combination with genetic reporter mice, nuclear stains, and exposure experiments, we demonstrate the feasibility of slice culture on a reproductive organ. We also provide a step-by-step protocol and troubleshooting guide to facilitate the adoption of slice culture with live imaging in other reproductive organs. Lastly, we discuss potential utilities and experiments that could be implemented with slice culture in reproductive sciences.

A Case Report of Primary Melanoma of the Urethra.

We illustrate a notable case of an 83-year-old male who presents to a community hospital with abdominal pain and hematuria. A few days after admission, an ulcerated lesion was found to be visible toward the ventral aspect of the penis, as well as bright red blood at the urethral meatus. An excisional biopsy of the urethral meatus, mid-urethra, and urethral tissue was done, and immunohistochemistry helped support the diagnosis of primary melanoma of the urethra. The pathophysiology and guidelines for treatment are discussed. Our purpose in putting forward this case is to present a rare diagnosis of primary melanoma of the male urethra and to emphasize the importance of early recognition to reduce the occurrence of invasive malignancy.

Female Urethroplasty with a Buccal Mucosa Graft using a Supraurethral Approach.

INTRODUCTION AND HYPOTHESIS: In the setting of recurrent female urethral stricture, urethroplasty offer the best chance of cure. However, which approach (dorsal or ventral) and which tissue (buccal mucosa, vaginal graft, vaginal flap) remain areas of controversy. In this article and accompanying video, we describe female urethroplasty with a supraurethral approach using a buccal mucosa graft. METHODS: A stricture of 3 cm in length was observed in the mid urethra. A supraurethral semi-lunar incision was made and dissection was performed up to the stricture. A dorsal urethrotomy was performed and a 3 × 2 cm oral mucosal graft was harvested from the left cheek. The mucosal graft was anastomosed to both urethral edges with running sutures. The graft was fixed to the supraurethral tissue with quilting sutures. A urethral catheter and a suprapubic catheter were left in place for 3 weeks. RESULTS: Following removal of the catheters, the patient was able to void satisfactorily with no incontinence. No complications were observed in the urethral area or at the graft harvest site. CONCLUSIONS: Buccal mucosa graft urethroplasty with a supraurethral approach is a reliable method in the treatment of female urethral stricture.

Etiology and management of urethral calculi: A systematic review of contemporary series.

Objective: To conduct a systematic literature review on urethral calculi in a contemporary cohort describing etiology, investigation, and management patterns. Methods: A systematic search of MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) databases was performed. Articles, including case reports and case series on urethral calculi published between January 2000 and December 2019, were included. Full-text manuscripts were reviewed for clinical parameters including symptomatology, etiology, medical history, investigations, treatment, and outcomes. Data were collated and analyzed with univariate methods. Results: Seventy-four publications met inclusion criteria, reporting on 95 cases. Voiding symptoms (41.1%), pain (40.0%), and acute urinary retention (32.6%) were common presenting features. Urethral calculi were most often initially investigated using plain X-ray (63.2%), with almost all radio-opaque (98.3%). Urethral calculi were frequently associated with coexistent bladder or upper urinary tract calculi (16.8%) and underlying urethral pathology (53.7%) including diverticulum (33.7%) or stricture (13.7%). Urethral calculi were most commonly managed with external urethrolithotomy (31.6%), retrograde manipulation (22.1%), and endoscopic in situ lithotripsy (17.9%). Conclusion: This unique systematic review of urethral calculi provided a summary of clinical features and treatment trends with a suggested treatment algorithm. Management in contemporary urological practice should be according to calculus size, shape, anatomical location, and presence of urethral pathology.

Age-Related Changes in Urethral Structure and Responds to Injury: Single-Cell Atlas of a Rat Model of Vaginal Birth Injury induced Stress Urinary Incontinence.

Stress urinary incontinence (SUI) greatly affects the daily life of numerous women and is closely related to a history of vaginal delivery and aging. We used vaginal balloon dilation to simulate vaginal birth injury in young and middle-aged rats to produce a SUI animal model, and found that young rats restored urethral structure and function well, but not the middle-aged rats. To identify the characteristics of cellular and molecular changes in the urethral microenvironment during the repair process of SUI. We profiled 51,690 individual female rat urethra cells from 24 and 48 weeks old, with or without simulated vaginal birth injury. Cell interaction analysis showed that signal networks during repair process changed from resting to active, and aging altered the distribution but not the overall level of cell interaction in the repair process. Similarity analysis showed that muscle, fibroblasts, and immune cells underwent large transcriptional changes during aging and repair. In middle-aged rats, cell senescence occurs mainly in the superficial and middle urothelium due to cellular death and shedding, and the basal urothelium expressed many Senescence-Associated Secretory Phenotype (SASP) genes. In conclusion, we established the aging and vaginal balloon dilation (VBD) model of female urethral cell anatomy and the signal network landscape, which provides an insight into the normal or disordered urethra repair process and the scientific basis for developing novel SUI therapies.

Urethra contouring on computed tomography urethrogram versus magnetic resonance imaging for stereotactic body radiotherapy in prostate cancer.

Accurate urethra contouring is critical in prostate SBRT. We compared urethra contouring on CT-urethrogram and T2-weighted MRI. The dice similarity coefficient, Jaccard index, Hausdorff distance and mean distance to agreement were evaluated. All four metrics indicate better agreement and less variability in urethra contouring on CT-urethrogram, compared to T2-weighted MRI.

Ultrasound imaging of male urethral stricture disease: a narrative review of the available evidence, focusing on selected prospective studies.

PURPOSE: To synthetize the current scientific knowledge on the use of ultrasound of the male urethra for evaluation of urethral stricture disease. This review aims to provide a detailed description of the technical aspects of ultrasonography, and provides some indications on clinical applications of it, based on the evidence available from the selected prospective studies. Advantages and limitations of the technique are also provided. METHODS: A comprehensive literature search was performed using the Medline and Cochrane databases on October 2022. The articles were searched using the keywords "sonourethrography", "urethral ultrasound", "urethral stricture" and "SUG". Only human studies and articles in English were included. Articles were screened by two reviewers (M.F. and K.M.). RESULTS: Our literature search reporting on the role of sonourethrography in evaluating urethral strictures resulted in selection of 17 studies, all prospective, even if of limited quality due to the small patients' number (varied from 28 to 113). Nine studies included patients with urethral stricture located in anterior urethra and eight studies included patients regardless of the stricture location. Final analysis was based on selected prospective studies, whose power was limited by the small patients' groups. CONCLUSION: Sonourethrography is a cost-effective and safe technique allowing for a dynamic and three-dimensional urethra assessment. Yet, because of its limited value in detecting posterior urethral strictures, the standard urethrography should remain the basic 'road-map' prior to surgery. It is an operator-dependent technique, which can provide detailed information on the length, location, and extent of spongiofibrosis without risks of exposure to ionizing radiation.

Novel Association of RAD54L Mutation with Müllerian Clear Cell Carcinoma of the Male Urethra: New Insights Regarding the Molecular Mechanisms of a Rare Tumour.

INTRODUCTION: Müllerian clear cell carcinoma of the male urethra is similar to that of the female genital tract in terms of morphology and immunohistochemical expression but is rarely observed in clinical practice. CASE PRESENTATION: Here, we report the case of a 65-year-old man diagnosed with Müllerian clear cell carcinoma who harboured a mutation in RAD54L. This patient was diagnosed by electrocautery and ultimately underwent prostatectomy. After a six-month follow-up period, no signs of recurrence or additional malignancy were found. Based on our analysis of the available literature, it appears that Müllerian clear cell carcinoma with RAD54L mutation has not been reported until now. CONCLUSION: This case enhances our knowledge of the molecular biology of Müllerian clear cell carcinoma of the male urethra, which will help clinicians select optimal treatment options for this rare cancer in patients with specific driver mutations.