非结核分枝杆菌肺病的临床病理特征及分子病理诊断

Clinicopathologic features and molecular pathological diagnosis of non-tuberculous mycobacterium pulmonary disease

目的 分析非结核分枝杆菌(NTM)肺病的临床病理特征及分子病理诊断,提高病理医生的诊断及鉴别诊断能力。方法 回顾性分析2016年11月至2022年4月首都医科大学附属北京胸科医院收治的57例NTM肺病患者的临床病理资料,光镜下观察组织学形态,行抗酸染色法查找抗酸杆菌,并进一步应用荧光定量聚合酶链式反应(FQ-PCR)技术检测结核分枝杆菌(MTB)DNA和探针熔解曲线法进行分枝杆菌菌种鉴定。结果 57例NTM肺病的分枝杆菌菌种鉴定结果:胞内分枝杆菌23例,蟾蜍分枝杆菌14例,堪萨斯分枝杆菌8例,鸟分枝杆菌7例,脓肿分枝杆菌3例,龟分枝杆菌2例。27例手术标本组织学特征主要表现为典型肉芽肿伴坏死13例,不典型肉芽肿伴坏死8例,纤维包裹性坏死3例,支气管扩张2例,非坏死性肉芽肿1例,脓肿分枝杆菌感染灶可见小脓肿形成。57例标本抗酸染色均查找到抗酸杆菌。抗酸杆菌分布在坏死、纤维素样渗出及组织细胞胞质;胞内分枝杆菌较易形成菌团;堪萨斯分枝杆菌可见异型菌。FQ-PCR技术均未检测到MTB DNA。结论 NTM肺病的临床病理学特征表现多样,没有特异性,分子病理技术能够显著提高明确诊断率。

Objective To analyze the clinicopathologic features and molecular pathological diagnosis of non-tuberculous mycobacterium(NTM) pulmonary disease to improve diagnosis and differential diagnostic capability of pathologists.Methods There was a retrospective analysis of 57 patients with NTM pulmonary disease in Beiing Chest Hos pital from December 2016 to April 2022. The histological morphology was observed under light microscope. Acid-faststaining was used to detect acid-fast bacilli(AFB). Fluorescent quantitative polymerase chain reaction(FQ-PCR)was performed to detect Mycobacterium tuberculosis(MTB)DNA. Mycobacteria was identified by melting curve analysis. Results Totally57 NTM pulmonary diseases were identified. Among them, M. intracellulare was the dominant cases, followed by M.xenopi, M. kansasii, M. avium, M. abscessus and M. chelomae. The histological features of 27 surgical specimens showed typical necrotizing granulomas, atypical necrotizing granulomas, fibrous encapsulated necrosis, bronchiectasis, and nonnecrotizing granulomas. The formation of small abscess was found in focal infection by M. abscessus. AFB was detected in 57 cases. AFB was observed in necrosis, fibrinous exudate, and cytoplasm of histiocytosis. In M. intracellulare lesions, AFB commonly occurred in clusters. Singular AFB was often seen in M. kansasii infection. In addition, MTB DNA was negative in 57 cases. Conclusion The clinicopathological features of patients with NTM lung disease are atypical and nonspecific. Molecular pathological techniques can significantly improve the rate of definitive diagnosis.