[A case of epithelial membrane antigen-positive leiomyosarcoma of the urinary bladder].

A 41-year-old woman was admitted with gross hematuria and pain on urination. Cystoscopy showed a huge and lobulated submucosal non-papillary bladder tumor. Pelvic computed tomography demonstrated a heterogeneous and enhanced lobulated mass, 8 cm in diameter, with extravesical invasion but there appeared to be no metastatic lesions. Transurethral biopsy revealed leiomyosarcoma pathologically. Total cystectomy and construction of an ileal conduit were performed. The tumor was histologically diagnosed as leiomyosarcoma. Immunohistochemical studies revealed the tumor to be positive for epithelial membrane antigen (EMA) and muscle actin but negative for desmin, and S-100. We reviewed 102 cases of vesical leiomyosarcoma reported in Japan. Among these 102 cases, there were no EMA-positive cases. Immunohistochemical and electromicroscopic evaluation should be performed to evaluate this disease.