Infectious Diseases and Global Health, University of Chicago Medical Center, Chicago, Illinois.
Department of Pathology, University of Chicago Medical Center, Chicago, Illinois.
Lab Med. 2021 May 4;52(3):e50-e52. doi: 10.1093/labmed/lmaa082.
Cording is a phenomenon in which acid fast bacilli grow in parallel and was previously used as a means of presumptive microscopic identification of Mycobacterium tuberculosis (TB). However, this process has been shown in multiple other nontuberculous mycobacterial (NTM) species. Here we present the case of an immunocompromised adult who presented with wrist pain, weight loss, and cough. A positron emission tomography scan showed uptake in the right ulna, multiple soft tissue sites, and the left lung. Biopsies and cultures were obtained from multiple sites, and the patient was ultimately diagnosed with disseminated Mycobacterium chelonae infection. The organism showed cording in culture. As seen in this patient, cording may occur in multiple NTM species and is not reliable as the sole indicator of the presence of TB.
成束是一种分枝杆菌沿长轴平行生长的现象，以前曾被用作结核分枝杆菌（TB）的推定显微镜鉴定方法。然而，这一过程在多种非结核分枝杆菌（NTM）物种中均有出现。在此，我们介绍了一位免疫功能低下的成年患者，其表现为腕痛、体重减轻和咳嗽。正电子发射断层扫描显示右侧尺骨、多个软组织部位和左侧肺部有摄取。从多个部位获取活检和培养物，最终诊断为播散性龟分枝杆菌感染。该病原体在培养中显示成束现象。正如本例患者所见，成束现象可能发生在多种 NTM 物种中，不能作为 TB 存在的唯一指标。
