右坐骨腫瘤を呈した前立腺癌骨転移

A CASE OF PROSTATIC CARCINOMA WITH CYSTIC METASTASIS TO RIGHT ISCHIUM

　80歳，男性。肉眼的血尿を主訴に入院。右大腿内側に手拳大の皮下腫瘤を触知し，画像診断では前立腺と連続性はなく，右坐骨の破壊と同部に嚢胞状腫瘤を認めた。前立腺と右坐骨部腫瘤の生検より，両組織とも中分化型の篩状腺癌であった。前立腺と右坐骨部腫瘍は内分泌療法で縮小し，画像診断では右坐骨部腫瘍は骨外には認めず，正常部との境界に淡い骨形成を認めた。

The formation of cystic mass in osteolytic lesion of prostatic carcinoma is very rare. We reported a 80-yearold prostatic carcinoma patient with osteolytic metastasis of right ischium which showed cystic mass, 9.2×5.8cm in size by CT scan. Needle biopsy of the prostate and right ischium revealed moderately differentiatedadenocarcinoma. Endocrine therapy was performed, which gave a satisfactory result.