自然穿孔をきたした膀胱肉腫様癌の1例

Abstract

65歳女.肉眼的血尿で膀胱内腫瘍を指摘された.膀胱はコアグラタンポナーデの状態で, 膀胱洗浄により血塊と共に悪臭の強い多量の壊死組織が排出された.膀胱鏡では左側壁から後壁を中心とする非乳頭状広基性腫瘍を認め, 膀胱粘膜全体が表面不整であった.骨盤部造影CTで膀胱左側壁を中心とする8×6cmの腫瘍を認め, 膀胱壁は全体に肥厚していた.1週間後の膀胱造影では左側壁からの造影剤漏出を認めた.膀胱癌T4N2M1と診断し, 発熱が増悪するため膀胱全摘術及び両側尿管皮膚瘻造設術を施行した.摘出組織で表面を壊死組織で覆われた灰白色の腫瘍を認め, 膀胱壁外に到達した部分に瘻孔が形成されていた.組織学的には表在性に位置する癌腫の部分と, 優勢な肉腫様部分で構成され, 両者の境界は明瞭であった.癌腫は扁平上皮に分化している細胞, 肉腫様部分は未分化な紡錘形細胞で構成されていた.術後一時的に改善したが発熱が再燃し, 2週後に敗血症で死亡した

A 65-year-old woman was referred to our clinic with gross hematuria. Cystoscopy revealed a non-papillary and non-pedunculated tumor on the left lateral wall of the bladder. A piece of necrotic tissue obtained from the bladder irrigation was histologically squamous cell carcinoma. A perforation at the left lateral wall of the bladder was found on the cystogram. Bone scintigraphy showed multiple metastases and computed tomography scans showed multiple lymph node metastases in the pelvic cavity. The clinical diagnosis was bladder carcinoma of T4N2M1 stage with an abscess due to a spontaneous perforation. Total cystectomy with bilateral ureterocutaneostomy was performed. She died due to sepsis 13 days after the operation. Histologically, the tumor was composed of carcinomatous and sarcomatous elements. The carcinomatous element was compatible with squamous cell carcinoma and the sarcomatous element was composed of undifferentiated malignant spindle cells. Immunohistochemical examination showed that the carcinomatous component was positive for keratin and human chorionic gonadotropin (HCG) and the spindle cell component positive for vimentin, desmin and HCG. Therefore, we diagnosed the tumor as sarcomatoid carcinoma. We reviewed 56 cases of carcinosarcoma of the bladder in Japan and discussed the clinicopathology of the disease.