Mathur Sandeep, Sood Rita, Aron Manju, Iyer Venkateswaran K, Verma Kusum
Cytopathology Laboratory, Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi.
Acta Cytol. 2005 Sep-Oct;49(5):567-70. doi: 10.1159/000326207.
Nocardiosis is an uncommon infection and presents as an opportunistic infection in an immunocompromised host. Pulmonary infection by Nocardia may be difficult to diagnose based on clinical and radiologic features, as these are not specific. Sputum examination, bronchoalveolar lavage and transthoracic ultrasound/computed tomography-guided fine needle aspiration cytology offer a simple means of procuring material for diagnostic evaluation. Very few articles have described the morphologic appearance of this uncommon pathogen in cytologic material.
Three cases occurred in patients with an underlying immunocompromised state. Patient 1 was on steroid therapy for nephrotic syndrome, patient 2 was on immunosuppressant therapy after renal transplantation, and patient 3 was HIV positive. A diagnosis of pulmonary nocardiosis was suspected on Papanicolaou stain. Modified Ziehl-Neelsen stain and silver methanamine stains were useful in confirming the diagnosis.
A high index of suspicion for nocardiosis must be maintained while assessing cytologic material in immunosuppressed individuals as it may be masked by the intense inflammatory exudate associated with this infection. A meticulous search may reveal the presence of delicate, thin, faintly stained, branching filaments of Nocardia on routine Papanicolaou stain. Special stains and culture studies are useful in confirming the diagnosis.
诺卡菌病是一种罕见的感染，在免疫功能低下的宿主中表现为机会性感染。诺卡菌引起的肺部感染基于临床和放射学特征可能难以诊断，因为这些特征并不具有特异性。痰检查、支气管肺泡灌洗以及经胸超声/计算机断层扫描引导下细针穿刺细胞学检查提供了一种获取用于诊断评估材料的简单方法。极少有文章描述这种罕见病原体在细胞学材料中的形态学表现。
三例发生于有潜在免疫功能低下状态的患者。患者1因肾病综合征接受类固醇治疗，患者2在肾移植后接受免疫抑制治疗，患者3为HIV阳性。在巴氏染色上怀疑为肺诺卡菌病。改良齐-尼氏染色和甲胺银染色有助于确诊。
在评估免疫抑制个体的细胞学材料时，必须高度怀疑诺卡菌病，因为它可能被与这种感染相关的强烈炎性渗出物掩盖。仔细查找可能会在常规巴氏染色上发现纤细、淡薄、淡染、分支的诺卡菌细丝。特殊染色和培养研究有助于确诊。
