Leiomyosarcoma

Malignant neoplasms of the bladder are typically transitional cell carcinoma with squamous cell carcinoma and adenocarcinoma comprising nearly all of the remaining cases. Leiomyosarcoma is a rarely seen neoplasm of the bladder with a generally poor prognosis. It is important to distinguish leiomyosarcomas from rhabdomyosarcoma with the aid of immunohistochemical markers. A therapeutic dilemma exists with regard to the need for urethrectomy. We present the third reported case of leiomyosarcoma of the bladder in a teenage male patient.

Introduction

Leiomyosarcoma of the bladder is rare, has a poor 5-year survival rate, and is most commonly seen in patients older than 50 years of age. Leiomyosarcoma is seen in a young patient rarely. When it is, consideration of a body image-sparing procedure is essential.

Case Report

A 19-year-old white man presented with a 4-week history of irritative voiding symptoms. The patient had been treated for a presumed urinary tract infection with multiple courses of antibiotics without resolution of symptoms. Physical examination was significant for a firm prostate slightly displaced to the left. Intravenous pyelogram demonstrated an 8-cm round extrinsic mass displacing the bladder to the left (Fig. 1). Cystoscopy revealed a 300-mL capacity bladder with normal mucosa, displacement of the trigone, and nonvisualization of the ureteral orifices secondary to extrinsic mass compression. Magnetic resonance imaging demonstrated a 9.2 × 8.0 × 8.0-cm heterogeneous soft tissue mass in the right pelvis that appeared to abut the right lateral wall of the bladder and then blend with the inferior right bladder wall. Computed tomography scan of the chest revealed no metastatic pulmonary lesions. The patient underwent exploratory laparotomy where the mass was found to be adherent to the base of the bladder with detrusor fibers firmly adherent and incorporated into the mass. Cystoprostatectomy was performed with an orthotopic ileal neobladder for urinary diversion. Postoperatively the patient did well and tolerated clean intermittent catheterization and irrigation of his neobladder without difficulty.

Grossly, the mass was 9.5 × 10.5 × 10.0 cm, was well circumscribed with areas of gross hemorrhage and necrosis, and invaded the detrussor muscle, causing mucosal ulceration. Histology showed a high-grade malignant neoplasm composed of pleomorphic spindle cells arranged in a vaguely fascicular pattern. The mitotic rate was brisk with more than 5 mitoses per 10 high-power fields. Lymph vascular invasion was identified; however, the surgical margins were free of tumor. Immunohistochemical stains confirmed a diagnosis of leiomyosarcoma as they were positive for desmin and smooth muscle actin (Fig. 2A), whereas myoglobin, a skeletal muscle marker, was negative (Fig. 2B).

Discussion

Leiomyosarcoma is generally seen in middle-age patients. Rare to begin with, leiomyosarcoma is seldom seen in a teenage male. Leiomyosarcoma is a highly malignant tumor with an extremely poor prognosis. Five-year disease-free survival is rare. In one series, only 7 of 62 case subjects had 5-year survival. Interestingly 6 of 7 were women. ' Another series of 5 patients had 1 patient survive beyond 5 years.2 In a third series, 4 of 10 patients were alive at 5 years. Of note, 3 of the 4 survivors were women.3 In addition to illustrating poor survival, these series demonstrate that being a female may confer a survival advantage. Wide local excision is considered treatment of choice with radiation and chemotherapy being offered to patients with positive margins, nodes, or those with bulky disease.4

An important aspect of management of leiomyosarcoma is to differentiate the lesion from rhabdomyosarcoma and other spindle cell neoplasms. This is especially difficult with poorly differentiated high-grade lesions. Leiomyosarcoma is less aggressive with a better prognosis and better therapeutic response to local measures. On immunohistochemistry, leiomyosarcomas will be negative for epithelial markers (cytokeratins and epithelial membranes antigen). Positivity for desmin and smooth muscle actin will show the smooth muscle origin of the tumor and give the definitive diagnosis. Negative myoglobin, cytokeratin, and S-IOO help to rule out rhabdomyosarcoma, sarcomatoid carcinoma, and melanoma, respectively.5

This case is unique for its presentation in a young patient; furthermore, cases of vesical leiomyosarcoma have almost exclusively been reported before the orthotopic era. While orthotopic neobladder should be considered for all patients, a body image-sparing procedure is of even greater consideration in a young patient. Of importance in orthotopic diversion is potential involvement of the urethra, which has been reported as a site of recurrence in leiomyosarcoma. In fact, Alabaster et al.6 advocate prophylactic urethrectomy. Leiomyosarcoma tends to spread locally. Limited experience has hampered the ability to determine if the concept of disease elsewhere in the urinary tract that exists in transitional cell carcinoma is found in leiomyosarcoma. Of the risks of urethral recurrence in transitional cell carcinoma, the most meaningful is involvement of the prostate or prostatic urethra. It has been recommended that when proceeding to orthotopic diversion, en bloc or delayed urethrectomy is indicated only if the frozen section of the prostatic urethra is positive at cystectomy.7 Until more data become available for leiomyosarcoma, it seems reasonable to follow transitional cell carcinoma recommendations for leiomyosarcoma.

References

1. Tara HH, Mentus NL: Leiomyosarcoma of urinaiy bladder. Urology 1973; 2: 460-2.

2. Palterson DE, Barrett DM: Leiomyosarcoma of the urinary bladder. Urology 1983; 21: 367-9.

3. Swartz DA, Johnson DE, Ayala AG, Watkins DL: Bladder leiomyosarcoma: a review of 10 cases with 5-year follow-up. J Urol 1985; 133: 200-2.

4. Ahlering TE, Weintraub P, Skinner DG: Management of adult sarcomas of the bladder and prostate. J Urol 1988; 140: 1397-9.

5. Mills SE, Bova GS, Wick MR, Young RH: Leiomyosarcoma of the urinary bladder: a clinicopathologic and immunohistochemical study of 15 cases. Am J Surg Pathol 1989; 13: 480-9.

6. Alabaster AM, Jordan WP, Soloway MS: Leiomyosarcoma of the bladder and subsequent urethral recurrence. J Urol 1981; 125: 583-5.

7. Elmajian DA: Indications for urelhrectomy. Semin Urol Oncol 2001; 19: 37-44.

Guarantor: CPT Eric R Richter, MC USA

Contributors: CPT Eric R. Richter, MC USA*; LTC Robert C. Dean, MC USA[dagger]

* Primary Care Care Line, Evans Army Community Hospital, 7300 Cochrane Circle, Fort Carson, CO 80913.

[dagger] Department of Surgery, Urology Service, Walter Reed Army Medical Center, 6825 Georgia Avenue, NW, Washington, DC 20307.

This manuscript was received for review in july 2002. The revised manuscript was accepted for publication in March 2003.

Reprint & Copyright © by Association of Military Surgeons of U.S., 2004.

Copyright Association of Military Surgeons of the United States Feb 2004
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