分散性分枝杆菌Chimaera感染是心胸外科手术后出现的新兴疾病，需要对异型表现进行怀疑。我们报告了一例74岁男性患者，患有原因不明的发热、双足紫色结节和开放性心脏手术史。影像检查显示主动脉生物瓣旁存在脓肿，但感染性心内膜炎筛查结果为阴性，发热不响应抗生素治疗。皮损活检显示为HHV8相关的卡波西肉瘤，因此进行了骨髓活检，并出现HHV8定位的证据。骨髓和尿液分枝杆菌培养结果显示为M. chimaera阳性，开始特定的抗微生物治疗，7周后发热消失。在出现心脏手术史的人群中，应始终将M.chimaera感染作为原因不明的发热的可能病因进行调查，即使血液分枝杆菌培养为阴性。不能排除分散性感染在诱导免疫抑制并导致其他机会性疾病（如卡波西肉瘤）的发生中的可能作用。©2022。作者（们）。

Disseminated Mycobacterium chimaera infection is an emerging disease in people undergone to cardiothoracic surgery, which need to be suspected also with atypical presentations.We report the case of a 74-year-old man with fever of unknown origin, purple nodules on both feet and a history of open-heart surgery. Imaging investigations showed an abscess near aortic bioprosthesis but screening for endocarditis resulted negative and pyrexia did not respond to antibiotic therapy. A biopsy of cutaneous lesions showed HHV8-related Kaposi's sarcoma, so bone marrow biopsy was executed with evidence of HHV8 localization. Bone marrow and urine mycobacterial cultures resulted positive for M. chimaera and a specific antimicrobial therapy was started, with apyrexia after 7 weeks.M. chimaera infection should be always investigated as a possible etiology of fever of unknow origin in people with a history of open-heart surgical intervention, even with negative mycobacterial blood cultures. The possible role of disseminated infection in inducing immunodepression with the occurrence of other opportunistic diseases (such as Kaposi's sarcoma) cannot be excluded.© 2022. The Author(s).