Paraurethral Leiomyoma Masquerading as a Periurethral Retention Cyst.

Abstract

Background: Paraurethral leiomyomas are rare benign tumours of the female genitourinary tract. A ratio of 1:1000 women present with periurethral masses, of which 5% are leiomyomas. They tend to occur in women of reproductive age, with a mean age of 40 years old. Aim(s): With intraoperative and post-operative images, we describe a case of a paraurethral leiomyoma. Case: A 51-year- old woman was referred to Urogynaecology clinic due to a vaginal lump, with associated burning and itching. Examination demonstrated a 2-cm mobile, mildly tender mass positioned anterolaterally to the right of the external urethral meatus. There was no urethral discharge. She was post-menopausal and her BMI was 31. Perineal ultrasound demonstrated a complex cystic structure, without communication to the urethra. MRI suggested a periurethral complex retention cyst. Result(s): She consented to surgical excision, which was performed under general anaesthetic. She was discharged that day, with an indwelling catheter remaining for 7 days. Four weeks later, her symptoms had largely resolved and examination was unremarkable. The histopathology showed a benign leiomyoma. Discussion(s): The highest incidence of paraurethral leiomyomas in women of reproductive age may reflect an oestrogen influence, consistent with paraurethral leiomyomas growing during pregnancy and regressing postpartum. However, others have questioned this hypothesis, noting cases of paraurethral leiomyomas in post-menopausal women. In our case, the patient's recent menopause reduces the time for a decrease in oestrogens to affect tumour size. Her elevated BMI may also contribute to peripheral oestrogen conversion. Therefore, this post-menopausal paraurethral leiomyoma can be considered consistent with the oestrogen-dependent hypothesis.