前立腺癌肉腫の1例

Abstract

63歳男性。患者は排便困難, 排尿困難を主訴に近医を受診, 直腸診にて前立腺肥大症を疑われ, 著者らの施設へ紹介となった。受診時, 腫瘍マーカーではPSA高値を示し, 自然尿細胞診はclass IIであり, 骨盤MRIでは前立腺と一塊となった径6.5cmの腫瘤が認められた。経直腸超音波ガイド下経会陰的腫瘤針生検術の結果, 前立腺原発または前立腺へ浸潤した線維肉腫と考えられ, 骨盤内臓全摘術, 回腸導管および人工肛門造設術が施行された。病理組織学的に前立腺癌肉腫と診断され, 腫瘍の直腸への浸潤を認めた。更に術後1ヵ月経過で会陰部から小骨盤にかけ局所再発が認められ, 放射線療法を試みたものの効果は得られず, 術後9ヵ月に患者は死亡となった。尚, 病理解剖所見では会陰部, 骨盤内, 両肺に線維肉腫の再発や転移が確認された。

A 63-year-old Japanese man with a 1-month history of dyschezia and dysuria was referred to our hospital. Transrectal ultrasonography and magnetic resonance imaging demonstrated a mass involving the prostate, measuring about 6.5 cm. The serum prostate specific antigen was 20.3 ng/ml. By the transperineal needle biopsy, it was suspected to be fibrosarcoma. Total pelvic exenteration was performed. Histopathological examination of the tumor revealed carcinosarcoma of the prostate. One month after the operation local recurrence was manifested by perineal pain. The recurrent tumor grew rapidly with severe pain. The patient's condition deteriorated, and finally he died of the disease nine months after the operation. Carcinosarcoma of the prostate is a rare neoplasm and very aggressive. There is no established protocol for its treatment and its prognosis is usually poor. This is the 49th case reported in the literature.