Transurethral Resection of a Large Urinary Bladder Leiomyoma: A Rare Case Report INTRODUCTION Bladder's benign mesenchymal tumors are quite rare, and constitute 1-5% of all bladder tumors.(1,2) Benign tum-ors that form in the bladder are myoma, leiomyoma, rhabdomyoma, fibroma, angioma, osteoma and myxoma. (3) Bladder leiomyoma is the most frequently observed benign mesenchymal tumor of the bladder, constituting 35% within this group. Therefore, bladder leiomyoma constitutes less than 0.5% of all bladder tumors.(4,5) Until now, there have been about 250 case reports of bladder leiomyoma. Based on its localization, bladder leiomyoma can be endovesical (63%), extravesical (30%), or intramural (7%). (6,7) Complaints from patients with bladder leiomyoma may consist of obstructive symptoms, irritative symptoms, and gross hematuria. Sometimes, however, patients may be asymptomatic.(7) Since the endovesical form is more symptomatic compared to forms at other localizations, it is usually diagnosed at an earlier stage.(5) Since the disease is rarely encountered, we wished to present the findings of a case with bladder leiomyoma diag- nosed at the Urology Department of Adıyaman University. University of Health Sciences, Dişkapi Yildirım Beyazit Training and Research Hospital, Department of Urolo- gy, Ankara, Turkey. *Correspondence: University of Health Sciences, Dişkapı Yildirim Beyazit Training and Research Hospital, Department of Urology, Ankara, Turkey. Tel: +90 532 603 11 81. Fax: +90 312 318 66 90. E-mail: alper_gok@hotmail.com. Received October 2016 & Accepted May 2017 ALPER GÖK Bladder leiomyoma constitutes less than 0.5% of all bladder tumors. Until now, there have been about 250 case reports of bladder leiomyoma. We present a case of large bladder leiomyoma, that was treated successfully with transurethral resection. The patient presented to our clinic with both obstructive and irritative urinary complaints. Cystoscopy showed a mass lesion completely obstructing the bladder neck at the junction of right lateral wall and floor, which did not extend to ureteral orifices. A transurethral resection was performed at the same session of cystoscopy. At the postoperative 3rd month control visit, the patient's obstructive symptoms were completely healed but her irritative symptoms continued. A repeat cystoscopy revealed residual tumoral tissue remaining at the floor of the previous surgical area. Transurethral resection was performed, and these tissues were completely resected. At the control visit that was 3 months after the second transurethral resection procedure, the patient was free from any urinary complaints. In conclusion, large bladder leiomyomas can be treated successfully with endo- scopic approaches. CASE REPORT Keywords: benign neoplasms; bladder; diagnosis; leiomyoma; transurethral resection Figure 1. Cystoscopy image of the tumor from bladder neck. Vol 14 No 04 July-August 2017 4052 CASE REPORT A forty-six year old female patient presented to our clinic with both obstructive and irritative urinary com- plaints. Her laboratory workup and abdominal physical examination was normal, bimanual vaginal examina- tion indicated a solid mass near the bladder neck. She did not have any comorbidity. Transvaginal ultrasono- graphic examination revealed a 9x6 cm tumoral lesion localized to the junction of right lateral wall and floor of the bladder. Renal ultrasonography showed that the kidneys were bilaterally normal. Cystoscopy showed a mass lesion completely obstructing the bladder neck at the junction of right lateral wall and floor, which did not extend to ureteral orifices (Figure 1). The epi- thelial lining of the bladder covering the mass lesion appeared normal. Upon the patient's consent, bipolar energy was used for transurethral resection of bladder tumor (TURBT) at the same session with cystoscopy. There was no significant bleeding during the TURBT so the lesion was completely resected as far as can be seen. On the postoperative 2nd day, the urethral cathe- ter was removed and the patient was discharged without any problems. In histopathological examination of the specimen that was obtained with TURBT, staining for alpha-smooth muscle antigen (SMA) and desmin were positive (Figures 2 and 3). There was no staining for PanCK at the tumoral area, but the surface epithelium stained positive. In addition, hematoxylin-eosin section showed a normal transitional epithelium, while the mus- cle fibers were in continuity with lamina propria under epithelial invaginations. These findings were consistent with leiomyoma. At the postoperative 3rd month control visit, the pa- tient's obstructive symptoms were completely healed but her irritative symptoms continued. A repeat cys- toscopy revealed residual tumoral tissue remaining at the floor of the previous surgical area. TURBT was performed, and these tissues were completely resected. At the control visit that was 3 months after the second TURBT procedure, the patient was free from any uri- nary complaints. DISCUSSION Benign mesenchymal tumors constitute a very small group within all bladder tumors. Leiomyoma is the most frequently encountered type among benign mes- enchymal tumors of bladder. The size of a leiomyoma can range from a few millimeters to 30 cm.(8,9) Gol- uboff et al.(7) reviewed 37 reported cases of leiomyoma and found that these patients most commonly present- ed with obstructive urinary symptoms (49%), irrita- tive symptoms (38%), hematuria (11%), or flank pain (13%); while 19 percent were asymptomatic. In that series, most patients were treated with open resection (62%), whereas 30 percent were treated with transure- thral resection.(7) Among those 37 patients, 76% were female and their age ranged between third and sixth decades. On the other hand, there are studies reporting equal distribution of gender among cases with bladder leiomyoma.(10,11) The exact cause of bladder leiomyoma is unclear. There are 4 factors held responsible in its etiology including hormonal disturbances, dysontogenesis, perivascular inflammation, and infection at the bladder's muscle lay- er.(4,12) Imaging techniques that can be used for diagnosing bladder leiomyoma include transabdominal ultrasonog- raphy, transvaginal ultrasonography, computed tomog- raphy, and magnetic resonance imaging. Some authors claim ultrasonography is a superior technique com- pared to other methods for imaging bladder leiomyoma, because it is better at revealing tumor's localization and its relation with neighboring organs.(13,14) Treatment of bladder leiomyoma is surgical resection. While TURBT is generally preferred for small-sized tu- mors with endovesical localization, partial cystectomy and segmental resection are preferred for larger tumors. Asymptomatic patients can be followed without sur- gery since there is no evidence that bladder leiomyoma can undergo malignant transformation.(8,9,15) Here, we presented a case with large bladder leiomyo- ma, a rarely encountered disease that was treated suc- cessfully with TURBT. Based on the experience of this case, we think, endoscopic resection of bladder leiomy- oma cause less bleeding than the endoscopic resection of other bladder tumor forms, and so the TURBT can be a good option for surgical resection of the bladder leiomyoma even in large tumors with endovesical lo- calization. CONFLICT OF INTEREST The author report no conflict of interest. TUR of Large Urinary Bladder Leiomyoma-Gok A. Case Report 4053 Figure 2. Muscle fibers appearing positively stained for X100 SMA Figure 3. Positive staining for X200 desmin REFERENCES 1. Campbell EW, Gislason GJ. Benign mesothelial tumors of the urinary bladder: review of literature and a report of a ease of leiomyoma. J. Urol. 1953;70:733–742. 2. Melicow MM. Tumors of the urinary bladder. J. Urol. 1937;37:117. 3. Goktug HG, Ozturk U, Sener NC, Tuygun C, Bakirtas H, Imamoglu AM. Transurethral resection of a bladder leiomyoma: A case report. Can Urol Assoc J 2014; 8: 111-113 4. Nazih K, Ghazi S. 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