BCG膀胱内注入療法による結核性精巣上体炎の1例

Abstract

76歳男性.患者は約4年前に膀胱癌で経尿道的膀胱腫瘍切除術後BCG膀胱内注入療法施行し, その1年後, 排尿困難で経尿道的前立腺切除術を行い, 切除標本中に多数の結核結節を認めたが経過観察中であった.だが今回, 右陰嚢腫大で受診となり, 右精巣上体尾部に無痛性硬結の触知より, 右精巣上体炎と診断してレボフロキサシンを投与を行った.しかし, 硬結は縮小したものの投与中止により増大し, 硬結陰嚢皮膚に形成された瘻孔からは膿の排出が認められた.この膿を塗沫検鏡で観察したところ抗酸菌が検出され, さらにPCR法ではウシ型結核菌と判定した.そのため, BCGによる右結核性精巣上体炎と診断し, 抗結核剤投与と右精巣摘除術を施行した.切除標本の病理組織所見では類上皮細胞とラングハンス巨細胞からなる肉芽腫が認められた.術後, 経過は良好で, 16ヵ月経過現在, BCG感染症の再発徴候は認めていない

We describe a case of tuberculous epididymitis that occurred 35 months after completion of a course of intravesical Bacillus Calmette-Guerin (BCG). A 67-year-old man had received trasuretheral resection for bladder cancer in February 1997. Two weeks after the operation, a course of 8 weekly intravesical instillations of BCG (Tokyo 172 strain) was carried out between March and April, 1997. Under the diagnosis of benign prostatic hypertrophy, transuretheral resection of the prostate was performed in March 1998. Multiple tuberculous nodules were histopathologically detected in resected prostatic tissues. The patient complained of a small nodule in the right epididymal tail in August 2001. The nodule developed during 6 weeks, with spontaneous perforation of the scrotal skin and discharge of pus. The pus contained acid-fast bacilli, which were shown to be tubercle bacilli by polymerase chain reaction (PCR) with pan-mycobacterium primer. MPB64-T2, T6 and pncA-7, 11C were positive, while PT-1, 2 and pncA-7, 10 were negative by PCR. These results revealed that Mycobacterium bovis (BCG Organism) was the cause of the epididymitis. Drug therapy for 3 months with rifampicin, isoniazid and ethambutol was initiated in September 2001, and right orchiectomy was performed in October. Histopathological examination showed tuberculous epididymitis. In this case, persistent BCG organisms may have reached the epididymis from the prostate, and may have been activated by immunosuppression associated with aging. In addition, PCR with species-specific primers was useful in differentiating Mycobacterium bovis from Mycobacterium tuberculosis.