Frazier Aletta Ann, Franks Teri J, Cooke Erinn O, Mohammed Tan-Lucien H, Pugatch Robert D, Galvin Jeffrey R
Department of Radiologic Pathology, Armed Forces Institute of Pathology, 14th St and Alaska Ave NW, Washington, DC 20306, USA.
Radiographics. 2008 May-Jun;28(3):883-99; quiz 915. doi: 10.1148/rg.283075219.
Pulmonary alveolar proteinosis (PAP) may develop in a primary (idiopathic) form, chiefly during middle age, or less commonly in the setting of inhalational exposure, hematologic malignancy, or immunodeficiency. Current research supports the theory that PAP is the result of pathophysiologic mechanisms that impair pulmonary surfactant homeostasis and lung immune function. Clinical symptomatology is variable, ranging from mild progressive dyspnea to respiratory failure. There is a strong association with tobacco use. The predominant computed tomographic feature of PAP is a "crazy-paving" pattern (smoothly thickened septal lines on a background of widespread ground-glass opacity), often with lobular or geographic sparing. The radiologic differential diagnosis of crazy-paving includes pulmonary edema, pneumonia, alveolar hemorrhage, diffuse alveolar damage, and lymphangitic carcinomatosis. Definitive diagnosis is made with lung biopsy or bronchoalveolar lavage specimens that reveal intraalveolar deposits of proteinaceous material, dissolved cholesterol, and eosinophilic globules. Symptomatic treatment includes whole-lung lavage, and multiple procedures may be required. New therapies directed toward the identified defect in immune defense have met with moderate clinical success.
肺泡蛋白沉积症（PAP）可呈原发性（特发性）形式出现，主要发生在中年，较少见于吸入暴露、血液系统恶性肿瘤或免疫缺陷的情况下。目前的研究支持这样一种理论，即PAP是损害肺表面活性物质稳态和肺免疫功能的病理生理机制的结果。临床症状各不相同，从轻度进行性呼吸困难到呼吸衰竭。与吸烟有很强的关联。PAP的主要计算机断层扫描特征是“铺路石样”表现（在广泛磨玻璃影背景上的光滑增厚的间隔线），常伴有小叶或区域 sparing。铺路石样表现的影像学鉴别诊断包括肺水肿、肺炎、肺泡出血、弥漫性肺泡损伤和淋巴管癌病。通过肺活检或支气管肺泡灌洗标本确诊，这些标本显示肺泡内有蛋白质物质、溶解的胆固醇和嗜酸性小球沉积。对症治疗包括全肺灌洗，可能需要多次操作。针对已确定的免疫防御缺陷开发的新疗法已取得一定的临床成功。
