目的　探讨偶发分枝杆菌 (MF)感染的组织病理学特征。方法　对 34例局部注射后发生MF感染病例 (39处病灶 )活检标本进行详细的病理学检查及分析。结果　局部MF感染的组织学表现可分为三种主要形式 ,显微镜下至少有七种以上的表现。结论　结节性或弥漫性炎症伴混合性肉芽肿 (中央为脓肿围绕着上皮样细胞及巨细胞 )以及坏死灶及肉芽肿样小结节周围出现大量空泡细胞条带或环状结构 (脂样结构 )为偶发分枝杆菌感染的最典型表现形式 Objective To investigate the histopathological features of Mycobacterium fortuitum (MF) infection. Methods Thirty-four patients with MF infection (39 lesions) after biopsy were examined by biopsy in detail. Results The histological findings of local MF infection can be divided into three main forms, with at least seven or more manifestations under the microscope. Conclusions Nodular or diffuse inflammation with mixed granulomas (central abscesses surrounding epithelioid cells and giant cells) and a large number of vacuolar cell bands or loops around the small nodules of necrotic and granulomatous Like structure) is the most typical manifestation of incidental mycobacterial infection