Peri-urethral lesions are a rare presentation to urology and gynaecology clinics. Clinical diagnosis can be challenging due to wide differential diagnoses including urethral diverticulum, caruncle, prolapse, peri-urethral cyst (Skene’s duct cyst), vaginal wall cyst (Müllerian and Gartner’s duct) and neoplasms. The authors present series of cases that presented to our institution over the last five years. Magnetic resonance imaging (MRI) was utilised to aid diagnosis following initial assessment and examination. The aims of this study were to evaluate the accuracy of MRI as a diagnostic tool in providing a pre-operative diagnosis and assisting with the operative planning.

Retrospective review of patients who presented with peri-urethral lesions between November 2013 and December 2018 were undertaken. The collected data included age, urological and gynaecological signs and symptoms, imaging, surgical management, histology and outcome.

27 patients were identified over a 5-year period. The median age was 32 years old with a range of 17-64 years old. The most common presenting symptoms were vaginal pain and/or dyspareunia in 19 (70%) patients and vaginal lump in 13 (48%) patients. Six (22%) patients had recurrent urinary tract infections, four (15%) stress urinary incontinence, three (11%) voiding dysfunction and one (4%) was asymptomatic. On clinical examination, all patients were found to have a solitary vaginal lump varying from 1 to 12.5 cm in size with average size of 2.6 cm. 
24 (89%) patients underwent trans-vaginal complete excision and three patients (11%) declined surgery. The standard surgical technique involved an inverted horseshoe incision in the anterior vagina, and this was used in majority (71%) of the cases. Histological examination confirmed the diagnosis of urethral diverticulum in 17 (71%) cases. Three patients had Skene’s duct cysts and three patients had Müllerian cyst based on histology. There was one patient with an arterio-venous malformation.  
MRI findings matched the histological diagnosis in 14 (58%) patients. Further three were reported as inconclusive.  
The median follow-up period was 4.5 months. Three patients did not attend their follow up appointment. Thirteen (54%) patients were found to have a complete resolution of their symptoms at their follow up and were discharged. One however was re-referred shortly after and underwent further excision for recurrence.  Four (17%) patients required further pain management of which one patient underwent a repeat MRI due to recurrent symptoms which was negative and patient referred to pain clinic. Five (21%) patients had mild urinary symptoms of which three patients underwent urodynamic assessment. In all three cases urodynamics showed a stable bladder function. Two of these patients required physiotherapy, further medical management and referral to pain clinic. There was one re-operation due to wound dehiscence and one patient received silver nitrate for the treatment of excess scar tissue.

Patients with peri-urethral lesions most commonly presented with dyspareunia in the presence of a vaginal lump. Lower urinary tract symptoms may be present and were varied. MRI was routinely used to aid diagnosis and in this cohort matched the histological diagnosis in the majority of the cases. More than half of the patients treated by surgical excision were symptom-free at follow up. Most of those with mild symptoms at follow up responded well to conservative measures including physiotherapy and further medical management. No correlation between size of lesion, histology and post-operative symptoms were identified.

The clinical diagnosis of peri-urethral lesions can be difficult and relies on high index of clinical suspicion and careful examination. MRI was useful in ascertaining anatomical detail, relationship with the urethra and pre-surgical road-mapping. In our series, surgical excision remains the best treatment intervention and furthermore surgery also provided histological diagnosis. In our series surgery correlated with MRI findings in the majority of cases.