上皮膜抗原(EMA)が陽性であった膀胱原発平滑筋肉腫の1例

Abstract

症例は41歳女性で3ヵ月前から続く排尿痛と肉眼的血尿を認め来院し, 膀胱炎の診断で約2週間抗生剤を投与したが症状が軽快しなかった.膀胱鏡検査で膀胱後壁から前壁にかけて粘膜には異常を認めなかったが, 表面平滑で5cm以上の大きさがある分葉状腫瘍性病変を認めた.骨盤部CT施行直後より高度の血尿と貧血状態を呈したため緊急入院となった.膀胱鏡視下に腫瘍生検を行った結果, 膀胱原発平滑筋肉腫と診断して膀胱全摘術と回腸導管造設術を施行し, 膀胱腫瘍に準じてリンパ郭清術を行った.外来にて経過観察としたが, 約4ヵ月後に多発性肺転移と骨盤内の大部分を占める局所再発を認めたため, 全身化学療法を2コース施行したが, 術後約1年6ヵ月で死亡した

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.