Organizing pneumonia (OP), characterized histopathologically by patchy filling of alveoli and bronchioles by loose plugs of connective tissue, may be seen in a variety of conditions. These include but are not limited to after an infection, drug reactions, radiation therapy, and collagen vascular diseases. When a specific cause is responsible for this entity, it is referred to as “secondary OP.” When an extensive search fails to reveal a cause, it is referred to as “cryptogenic OP” (previously called “bronchiolitis obliterans with OP”), which is a clinical, radiologic, and pathologic entity classified as an interstitial lung disease. The clinical presentation of OP often mimics that of other disorders, such as infection and cancer, which can result in a delay in diagnosis and inappropriate management of the underlying disease. The radiographic presentation of OP is polymorphous but often has subpleural consolidations with air bronchograms or solitary or multiple nodules, which can wax and wane. Diagnosis of OP sometimes requires histopathologic confirmation and exclusion of other possible causes. Treatment usually requires a prolonged steroid course, and disease relapse is common. The aim of this article is to summarize the clinical, radiographic, and histologic presentations of this disease and to provide a practical diagnostic algorithmic approach incorporating clinical history and characteristic imaging patterns.

机化性肺炎 (OP) 的组织病理学特征是肺泡和细支气管被松散的结缔组织塞片状充盈，可见于多种病症。这些包括但不限于感染后、药物反应、放射治疗和胶原血管疾病。当特定原因导致该实体时，它被称为“次要 OP”。当广泛的搜索未能揭示病因时，它被称为“隐源性 OP”（以前称为“闭塞性细支气管炎伴 OP”），这是一种临床、放射学和病理学实体，被归类为间质性肺疾病。OP 的临床表现通常与其他疾病相似，例如感染和癌症，这可能导致诊断延迟和对潜在疾病的不当治疗。OP 的影像学表现是多形性的，但通常有胸膜下实变，伴空气支气管征或单发或多发结节，结节时强时弱。OP 的诊断有时需要组织病理学证实并排除其他可能的原因。治疗通常需要延长类固醇疗程，并且疾病复发很常见。本文的目的是总结该疾病的临床、放射学和组织学表现，并提供结合临床病史和特征性成像模式的实用诊断算法方法。治疗通常需要延长类固醇疗程，并且疾病复发很常见。本文的目的是总结该疾病的临床、放射学和组织学表现，并提供结合临床病史和特征性成像模式的实用诊断算法方法。治疗通常需要延长类固醇疗程，并且疾病复发很常见。本文的目的是总结该疾病的临床、放射学和组织学表现，并提供结合临床病史和特征性成像模式的实用诊断算法方法。