Hee-Jung Jun, et al. chest radiography revealed that the size of the cavitary lesion in the left upper lobe was unchanged, although the multiple nodular lesions in the right lung had improved (Fig. 1C). Chest computed tomography revealed a large remnant cavitary lesion that involved both the left upper lobe and the superior segment of the left lower lobe (Fig. 1D). This cavitary lesion was considered to have a high possibility of relapse. Therefore, the patient underwent a left upper lobectomy and superior segmentectomy of the left lower lobe. The microscopic findings were parenchy- mal destruction with cavity and chronic granulomatous inflammation with caseous necrosis. The tissue culture was not requested during the surgery. The patient was consider- ed cured after receiving 12 months of postoperative anti- mycobacterial chemotherapy. There has been no recurrence of disease 18 months after treatment completion. DISCUSSION To the best of our knowledge, this is the first case of M. celatum lung disease being successfully treated with antimycobacterial chemotherapy in combination with pul- monary resection in Korea. In this case, M. celatum was clearly shown to be the etiologic agent of the cavitary lesion of the left lung. Considering the clinical and radio- graphic features, in addition to the repeated isolation of M. celatum, the diagnostic criteria for NTM lung disease were fulfilled.1 The clinical outcome for many M. celatum-infected patients is poor, probably due to their profound immuno- suppression. The previously reported immunocompetent patients with pulmonary infection were assigned different treatment regimens with combinations of antimycobac- terial agents, mainly ethambutol and clarithromycin.7-9 Clinical improvement was obtained within 6 months of the initiation of therapy in two out of three patients. One pati- ent who received anti-mycobacterial therapy died 6 weeks after starting therapy from complications that were appa- rently related to the M. celatum infection.7 The susceptibility test profiles of the previously reported cases showed variability.5-9 The organism was generally found to be susceptible to clarithromycin and ciprofloxa- cin, with ciprofloxacin resistance being reported infrequen- tly.13-15 All the reported isolates were resistant to rifampin and most were resistant to isoniazid. In an animal model of M. celatum infection, clarithromycin, azithromycin, and ethambutol were shown to be the most active agents.16 Susceptibility testing is advisable in order to guide treat- ment choices. Based on the recommended treatment regi- mens and the results of in vitro susceptibility testing, we selected a combination of ethambutol, clarithromycin, and ciprofloxacin for our patient. However, organisms such as M. celatum have limited in vitro susceptibility, with limited evidence for a correlation between in vitro susceptibility and clinical response in the treatment of M. celatum pul- monary disease.1 In summary, M. celatum is an infrequent cause of poten- tially treatable pulmonary disease in immunocompetent subjects. Patients with M. celatum lung disease who can tolerate resectional surgery might be considered for sur- gery, especially in cases of persistent cavitary lesions des- pite antimycobacterial chemotherapy. ACKNOWLEDGEMENTS This work was supported by the Korea Science and Engi- neering Foundation (KOSEF) grant funded by the Korea government (MEST) (R11-2002-103). REFERENCES 1. Griffith DE, Aksamit T, Brown-Elliott BA, Catanzaro A, Daley C, Gordin F, et al. An official ATS/IDSA statement: diagnosis, treatment, and prevention of nontuberculous mycobacterial diseases. Am J Respir Crit Care Med 2007;175:367-416. 2. 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