Mycobacterium celatum Lung Disease uncommon cause of human infection, with an invasive disease occurring primarily in the form of acquired immuno- deficiency syndrome (AIDS) patients.6 There are only a few case reports of M. celatum lung disease in immuno- competent patients.7-9 To date, only one case of M. celatum lung disease has been reported in Korea.10 However, this patient was given first-line anti-tuberculosis drugs and the treatment outcome is unknown. We report an immunocompetent adult patient with M. celatum lung disease who was successfully treated with a pulmonary resection in combination with antimycobacterial chemotherapy with clarithromycin, ethambutol, and cipro- floxacin. CASE REPORT A 35-year-old woman was referred to our hospital for fur- ther examination and management of probable NTM lung disease. The patient’s medical history included a pulmo- nary tuberculosis episode when she was 21 years old. She lived in an urban area and had no history of smoking, alcoholism, or use of immunosuppressive drugs. Four months before her visit to our hospital, the patient reported a three-month history of a productive cough. A chest radiograph revealed a large cavity in the left upper lobe. The patient was initially diagnosed with pulmonary tuberculosis and received isoniazid, rifampin, ethambutol, and pyrazinamide. Two months later, NTM were cultured from her sputum, and the colonies were identified as M. celatum. She was referred to our hospital for probable NTM lung disease. Physical examination upon presentation showed that the patient was 162 cm tall and weighed 44 kg. The results of the clinical laboratory tests were unremarkable, apart from a moderately elevated erythrocyte sedimentation rate (69 mm/hr) and C-reactive protein (0.69 mg/dL). A human im- munodeficiency virus antibody test was negative. A chest radiography revealed a large cavitary lesion in the left upper lobe and multiple nodular opacities that involved the right lung (Fig. 1A), which appeared to improve slightly after 4 months of treatment with anti-tuberculosis drugs. Her sputum was positive in acid-fast bacilli (AFB) staining, and numerous mycobacterial colonies were cultured from three sputum specimens at our hospital. All of these colonies were subsequently identified as M. celatum. This identification was confirmed using a polymerase chain reaction (PCR)-restriction fragment length polymorphism method, based on the rpoB gene.11 Although the patient was recommended for a further work-up and a change of drug regimen, she was lost from follow-up. Twenty-two months later, the patient revisited our hospi- tal due to a persistent productive cough. A chest radiogra- phy showed aggravation of the cavitation in the left upper lobe, as well as enlargement of the nodular lesions in the right lung (Fig. 1B). The smears of two sputum specimens were positive for AFB, and yielded M. celatum. Antimi- crobial susceptibility testing was performed at the Korean Institute of Tuberculosis. The isolate was found to be susceptible to clarithromycin [minimal inhibition concen- tration (MIC), 1 µg/mL] and ciprofloxacin (MIC, 0.25 µg/mL) using the broth microdilution method according to the guidelines set forth by the National Committee for Clinical Laboratory Standards (NCCLS).12 In addition, using the absolute concentration method on the Lowenstein- Jensen medium, the isolate was shown to be susceptible to ethambutol (critical concentration, 2 µg/mL), streptomycin (critical concentration, 10 µg/mL), and kanamycin (critical concentration, 40 µg/mL), but resistant to isoniazid (critical concentration, 0.2 µg/mL) and rifampin (critical concentra- tion, 40 µg/mL). Combination antimycobacterial chemo- therapy, which included clarithromycin (1,000 mg/day), ethambutol (800 mg/day), and ciprofloxacin (1,000 mg/day), was initiated. Conversion to negative sputum cul- tures was achieved in 3 months. Despite 12 months of antimycobacterial chemotherapy, the patient suffered from persistent sputum production. A A C B D Fig. 1. A 35 year-old woman with Mycobacterium celatum lung disease. (A) The posteroanterior chest radiography at first visit shows a large cavitary lesion in the left upper lobe. Note the multiple nodular opacities involving the right lung. (B) The chest radiography at the subsequent revisit shows aggravation of the cavitation in the left upper lobe, as well as enlargement of the nodular lesions in the right lung. (C) The chest radiography taken after 12 months of antibiotic treatment shows that the size of the cavitary lesion in the left upper lobe is unchanged, although the multiple nodular lesions in the right lung have improved. (D) The chest computed tomography scan taken after 12 months of antibiotic treatment reveals a large remnant cavitary lesion that involves both the left upper lobe and the superior segment of the left lower lobe. Yonsei Med J http://www.eymj.org Volume 51 Number 6 November 2010 981