Leiomyoma originating primarily in the vagina is relatively rare with approximately 300 cases reported. 1 The site of origin is the smooth muscle of the vaginal wall and the lesion is usually not associated with uterine leiomyoma. Careful histological examination of these tumors is essential to exclude malignancy, such as leiomyosarcoma. We report an unusual case of vaginal leiomyoma mimicking a urethral diverticulum. CASE REPORT A 36-year-old woman was referred for urological consultation after gynecological evaluation revealed a urethral diverticulum. She complained of dyspareunia and terminal dribbling after voiding as well as a history of frequent urinary infections, although none was documented on urinalysis or urine culture. Urinalysis was negative. There was no abnormal vaginal bleeding and a Papanicolaou smear was normal. Physical examination demonstrated a round, nontender 5 cm. midline suburethral mass in the anterior vaginal wall that was compressible without a purulent discharge via the urethra. Voiding cystourethrography, positive pressure urethrography and cystoscopy did not reveal a urethral diverticulum. At transvaginal exploration a well circumscribed 3 3 3 cm. soft tissue mass was identified extending under the trigone proximal to the left ureteral orifice (fig. 1). There was no connection to the urethra or bladder. The mass was excised completely. Pathological analysis of the specimen revealed leiomyoma (fig. 2). DISCUSSION The differential diagnosis of a suburethral mass includes urethral diverticulum, urethrocele and/or cystocele, Gartner’s duct cyst, vaginal inclusion cyst, urethral cancer, Skene’s abscess, vaginal carcinoma, ectopic ureterocele and leiomyoma. In females complaining of urinary dysfunction, dyspareunia and a palpable suburethral mass the major clinical suspicion is urethral diverticulum. Physical examination enables an accurate diagnosis of urethral diverticulum to be made in approximately 60% of cases, and cystoscopy and voiding cystourethrography have greater than 90% sensitivity. 2 When these diagnostic studies are negative, other possible etiologies should be considered. Vaginal leiomyoma commonly develops in the midline anterior vaginal wall in women 35 to 50 years old. 3 The clinical presentation of these rare tumors varies, and many are small, asymptomatic vaginal masses. Large lesions may cause pain and urinary tract symptoms. Vaginal leiomyoma, a mesenchymal neoplasm, is a rare smooth muscle tumor of the vagina that does not involve the vaginal mucosa or urethral epithelium. Treatment is surgical excision via the vaginal approach. The mass, which may be easily separated from surrounding tissue, is usually firm, well circumscribed, homogeneous and gray-white. Careful histological evaluation to assess the number of mitotic figures as well as cellular pleomorphism is essential to rule out leiomyosarcoma. These tumors are classified as intermediate histology leiomyoma or leiomyosarcoma. Those with an intermediate histology should be followed closely with serial examinations for recurrence. Leiomyosarcoma likely requires more aggressive resection and possibly adjuvant therapy. CONCLUSIONS
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