SCC抗原高値を呈し肺癌の併発が疑われた内科治療抵抗性の肺非結核性抗酸菌症

Nontuberculous Mycobacteriosis Resistant for Chemotherapy which was Suspected to Coexist with Lung Cancer

肺非結核性抗酸菌症（NTM）は近年増加している1）．肺NTM治療の第一選択は多剤併用の抗菌薬治療であるが，内科治療に抵抗性の症例では病状コントロール目的で外科療法が必要となる場合がある2）．化学療法によって陰影が改善しない場合，肺NTMの悪化が第一に考えられるが，これまでも肺NTMと肺癌の合併例が報告されているように，肺癌併発の可能性も考慮する必要がある3，4）．われわれはSCC高値を呈し肺癌の併発が疑われた内科治療抵抗性の肺NTMを経験したので，文献的考察を加えて報告する．

Nontuberculous mycobacteriosis （NTM） has been increasing recently. The treatment of choice of NTM is chemotherapy. Surgical treatment is sometimes indicated for patients with refractory NTM. When NTM lesion is enlarging despite of chemotherapy, there are 2 possibilities：intractable NTM and co-existing lung cancer. A 67-year-old male had been treated for fibro-cavitary NTM in the right upper lobe with chemotherapy. The cavitary lesion, however, was growing in spite of 6 months treatment. We suspected of a co-existing lung cancer because SCC level and standardized uptake value （SUV） in positron emission tomography （PET）-computed tomography （CT） were high. Bronchoscopy was performed but revealed no malignancy. He underwent a right upper lobectomy and the intraoperative pathology indicated NTM with no malignancy. After the operation, SCC levels decreased. This is a rare case with preoperative high SCC level which seemed to be related to NTM lesion.