A case of endobronchial tuberculosis mimicking bronchial asthma

症例は70歳代男性.乾性咳嗽を主訴として近医を受診した.胸部聴診で喘鳴を認め,気管支喘息と診断され,６ヵ月に渡り吸入ステロイドを含む治療を受けたが症状の改善は認められなかった.胸部CT検査が行われ,気管狭窄を指摘されたことから当院に紹介受診となった.当院での胸部CT検査では気管狭窄に加えて右上肺野に微細粒状影と気管支壁肥厚が認められた.気管支鏡検査では,気管下部で内腔の発赤,腫脹,狭窄を認め,左主気管支には白苔を伴う潰瘍性病変がみられた.気管支洗浄液の抗酸菌塗抹検査で抗酸菌を認め,PCR法で結核菌陽性であったため,肺･気管支結核と診断した.抗結核療法により,肺野陰影および症状の改善が認められ,治療後の気管支鏡検査では,左主気管支の白苔は消失したが,気管下部は瘢痕狭窄を来していた.気管支喘息の経過中に十分な治療を行っているにもかかわらず,症状が改善しない場合には,気管支結核の可能性を考える必要があり,喀痰検査や画像診断を適宜施行し 必要に応じて気管支鏡検査を考慮することが望ましい.気管支結核症は排菌率が高く,かつ病態の進展に伴い中枢気道の狭窄･閉塞をきたす可能性があるので,早期の診断･治療が必要である.

A 74-year-old man complaining of nonproductive cough and wheeze had been treated with inhaled corticosteroidin diagnosis of bronchial asthma for 7 months. He was referred to our hospital because his symptoms continued and the tracheal stenosis was detected.CT scans on admission showed the stenosis of trachea, and thickened bronchial walls and several nodular lesions in the right upper lobe. A bronchoscopic examination showed the stenosis in the middle portion of trachea with edema and congestion of the mucosa. The ulceration with white coat of the mucosa was observed in the left main bronchus. Mycobacterium tuberculosis was detected on a bronchial lavage fluid and he was diagnosed to have endobronchial tuberculosis. Antituberculosis treatment with isoniazid, rifampicin, ethambutol and pyrazinamide was started. Symptoms improved soon by antituberculosis treatment. A bronchoscopic examination conducted at 6 months later, the stenosis of trachea still remained, but edema and congestion have improved. The ulceration with white coat have improved leaving scar. In the case of bronchial asthma refractory to the adequate treatment, we have to consider the possibility of endobronchial tuberculosis.

気管支結核

気管支狭窄

気管支喘息