ウシ型結核菌（BCG）が原因と考えられた幼児の上腕骨結核性骨髄炎の1例

Tuberculous Osteomyelitis of the Humerus Caused by BCG Vaccination in a Young Child. Case Report

　症例は4歳，男児で，生後4カ月で左上腕部にBCGを接種した．その19カ月後から誘因なく左肩痛が出現し，化膿性骨髄炎と診断され，抗生剤投与により速やかに症状は消失した．しかし，2年後に左肩痛が再発し，穿刺により一部粕状の黄白色の膿を認めたため，結核性骨髄炎を疑い，直ちに病巣掻爬術を施行した．組織学的には乾酪壊死が存在し，結核性骨髄炎と診断されたが結核菌は検出されなかった．本症例では周囲に結核罹患者が存在しないことと結核感染に伴う呼吸器症状や全身所見がないことからBCG接種が原因と推察された．

　The patient was a 4-year-old boy who had been vaccinated with BCG at 4 months of age. He developed left shoulder pain 19 months after the vaccination, and was started on antibiotic therapy because of suspicion of purulent osteomyelitis. The shoulder pain immediately resolved, but 25 months later it recurred, and MRI revealed a large abscess in the shoulder. By the aspects of the aspiration abscess, tuberculous osteomyelitis was suspected, and curettage was performed immediately. The abscess contained a massive amount of yellow-white pus and debris, and pathologic examination suggested tuberculous osteomyelitis, but bacterial culture and the polymerase chain reaction (PCR) technique showed no evidence of tubercule bacilli. And BCG vaccination was suspected of having caused the osteomyelitis, because the patient had not been in contact with any tuberculosis patients and he had no manifestations of pulmonary or miliary tuberculosis.