Non-tuberculous mycobacterial pulmonary disease may have different clinical manifestations. We report a case of a 64-year-old woman presenting with persistent respiratory complaints, fever and radiological findings. Initially, she was diagnosed with community-acquired pneumonia, but after being submitted to an extensive investigation, including CT-guided transthoracic lung biopsy, a diagnosis of organising pneumonia (OP) was established. The patient was treated with corticosteroids with no favourable response. Subsequently, Mycobacterium avium complex (MAC) was identified in bronchoalveolar lavage culture. The patient was diagnosed with OP secondary to MAC infection and specific antibiotic treatment was initiated. This case represents an infrequent association and illustrates how important it is to investigate primary causes of OP to obtain a satisfactory treatment response.

中文翻译：

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继发性机化性肺炎的罕见病因

非结核分枝杆菌肺病可有不同的临床表现。我们报告了一名 64 岁女性的病例，她出现持续的呼吸道不适、发烧和放射学检查结果。最初，她被诊断出患有社区获得性肺炎，但在接受了包括 CT 引导的经胸肺活检在内的广泛调查后，确诊为机化性肺炎 (OP)。患者接受皮质类固醇治疗，但无良好反应。随后，在支气管肺泡灌洗培养物中鉴定出鸟分枝杆菌复合体 (MAC)。患者被诊断为继发于 MAC 感染的 OP，并开始了特定的抗生素治疗。