成人発生前立腺肉腫の臨床的検討

Clinical outcome of prostatic sarcoma in adults

今回われわれは，過去30年間に経験した成人前立腺肉腫および肉腫様癌について臨床的検討を行った。症例の内訳は，平滑筋肉腫3例，胎児性横紋筋肉腫1例，肉腫様癌が1例であった。患者の平均年齢は56.2歳（23～74歳）であった。初診時診断は前立腺肥大症2例，急性前立腺炎2例で，前立腺腫瘍を疑った症例は1例のみであった。PSAの上昇を認めた症例はなかった。全例に対して手術を施行した。うち3例は術後2か月以内に再発，転移を認め，いずれも術後3か月から15か月で腫瘍死した。大きな前立腺を有する中高年患者ではPSAの値にかかわらず前立腺肉腫の可能性があることを念頭におくべきと考えられた。

Adult prostatic sarcoma is a rare malignant tumor,and the prognosis is very poor. We report the clinical outcomes of 5 patients with adult prostatic sarcoma（3 with leiomyosarcoma,1 with embryonal rhabdomyosarcoma）and sarcomatoid carcinoma,which were treated at our institute. The mean age was 56.2 years（range 23 to 74）. Chief complaints at the initial presentation were related to bladder outlet obstruction,two patients being diagnosed as having BPH,and the other 2 as having acute prostatitis. Prostatic malignancy was suspected in only one. Prostate size was 5cm or larger in diameter in all cases by computed tomography or ultrasonography. PSA levels were normal in all cases. All patients were initially treated with surgical resection. Postoperatively,local recurrence or metastasis developed in 3 patients within 2months,and they died at 3,4,and 15months,respectively. In the current cases,early diagnosis of adult prostatic sarcoma was difficult because there was an overlap of symptoms with benign disease of the prostate. In conclusion,we should always pay careful attention to the possibility of prostatic sarcoma when we encounter a middle-aged patient with an extremely large prostate and a normal PSA level.