前立腺癌と抗Jo-1抗体陽性の多発性筋炎を合併した1例

Abstract

76歳男.前立腺特異抗原高値の精査中, クレアチンホスホキナーゼ(CPK)2841IU/Lを認めた.骨盤MRIでは辺縁領域にT2強調画像でび漫性の低信号域を認め, 辺縁は不整であった.骨盤造影CTは閉鎖リンパ節の腫脹を認めた.又, 抗Jo-1抗体173(9>)であった.下肢MRIでは筋肉全体に萎縮傾向を認めた.筋電図検査ではFibrillation, positive sharp waveを認めた.他の悪性疾患の合併はみられなかった.前立腺癌(臨床病期:D1, cT3a, N1, M0)に合併した抗Jo-1抗体陽性の多発性筋炎と診断した.LH-RH analogue, プレドニゾロンの投与を開始した.CPK, 抗Jo-1抗体, 自覚症状は徐々に軽快し, 治療開始後8ヵ月現在, プレドニゾロンを漸減して経過観察中である

A 76-year-old male was hospitalized with elevation of prostate specific antigen. We closely examined him further because creatine phosphate kinase was found to be 2, 841 IU/l in the pre-operative examination. He was positive for anti Jo-1 antibody, and was found to have muscular atrophy of lower extremities on magnetic resonance imaging, and fibrillation and positive sharp waves on the electromyogram. He was therefore diagnosed with polymyositis. Adenocarcinoma was classified as Gleason score 8 by needle biopsy of the prostate and the stage of the prostate carcinoma was cT3aN1M0. The patient was treated with hormonal ablation and oral steroids.