Pulmonary, Alveolar Proteinosis. The differential diagnosis for the “crazy-paving sign” is actually quite large and goes well beyond Pulmonary Alveolar Proteinosis (PAP). Conflict of Interest. It is typically … Very rarely, it also displays a “crazy paving” pattern (also described as a “paving stone,”“flagstone,” or “slabstone” pattern), which is rarer still in discrete bilateral nodules. • Delayed diagnosis due to infectious mimickers is common in the young age group. 200, P16-P17, 2019 PAP. sign of alveolar proteinosis. Idiopathic Disorders Pulmonary Alveolar Proteinosis These findings are characteristic but not unique to PAP. crazy paving pattern typical of pulmonary alveolar proteinosis (fi gure). Acta Radiol. Pulmonary Alveolar Proteinosis. A bronchoscopic alveolar lavage revealed alveolar proteinaceous material compatible with the diag-nosis pulmonary alveolar proteinosis (PAP). Nowadays this pattern is a common finding on high-resolution CT imaging, and can be seen in a number of acute and chronic diseases. Background: Although pulmonary alveolar proteinosis (PAP) and exogenous lipoid pneumonia (ELP) require different treatment strategies, both manifest as a crazy-paving pattern on CT and often have similar clinical manifestations and radiologic features. A crazy paving pattern is the combination of enlarged pulmonary blood vessels and a hazy appearance in the lungs. crazy-paving pattern (i.e., smoothly thickened intralobular interstitial lines and interlobular septal lines against a background of wide-spread ground-glass opacities) often with lob- ular or geographic sparing [3, 4]. No source of funding or conflict of interest. This is a CT-related term that refers to presence of pulmonary ground glass opacity with superimposed interlobular septal thickening and intralobular lines, resembling irregularly shaped paving stones. Although this pattern is suggestive of the diagnosis of pulmonary alveolar proteinosis, this pattern can be seen in several air-space and interstitial diseases . Reference: 1. Chest CT Scan. • Autoimmune pulmonary alveolar proteinosis requires timely diagnosis. Imaging description The classic appearance of pulmonary alveolar proteinosis is symmetric, predominately perihilar, ground-glass opacity with intralobular linear opacities and interlobular septal thickening (“crazy-paving” pattern) [1–3] (Figures 19.1–19.4). Authorship 18.1. CONCLUSION: Crazy paving pattern caused by pulmonary alveolar proteinosis displayed clear edges, and smooth reticular opacities, most of which were due to hemangiectasis of interlobular, interacinar and interalveolar septa. The finding is seen in pulmonary alveolar proteinosis, and other diseases. Pulmonary alveolar proteinosis Sandeep M Patel MD1, Hiroshi Sekiguchi MD 2, Jordan P Reynolds MD3, ... ‘crazy-paving’ pattern that need to be considered and ruled out before making a diagnosis of PAP? manifest as a crazy-paving pattern (Fig 4). Crazy-paving. DISCUSSION: PAP is thought to result from either overproduction of surfactant by type II pneumocytes or impaired clearance by alveolar macrophages. invasions. Crazy paving radiography finding in asymptomatic pulmonary alveolar proteinosis Young Rak Choi, You-Jin Chang, Si Wook Kim, Kang Hyeon Choe, Ki Man Lee, and Jin-Young An Asian Cardiovascular and Thoracic Annals 2014 23 : 5 , 588-590 An award-winning, radiologic teaching site for medical students and those starting out in radiology focusing on chest, GI, cardiac and musculoskeletal diseases containing hundreds of lectures, quizzes, hand-out notes, interactive material, most commons lists and pictorial differential diagnoses . REVIEW: PULMONARY ALVEOLAR PROTEINOSIS c EUROPEAN RESPIRATORY REVIEW VOLUME 20 NUMBER 120 99. alveolar accumulation. It was first described in the late 1980s in patients with pulmonary alveolar proteinosis, but has now been described in association with at least 15 pulmonary diseases. The crazy-paving pattern is a linear pattern superimposed on a background of ground-glass opacity, resembling irregularly shaped paving stones. The aforementioned HRCT findings constitute the crazy-paving pattern, which is characterized by diffuse ground-glass opacities in the lung parenchyma, together with interlobular and intralobular septal thickening. Request PDF | Crazy Paving in Pulmonary Alveolar Proteinosis | A 34-year-old man presented with dyspnea and a nonproductive cough. A chest CT showed a crazy-paving pattern. Anti-granulocyte macrophage-colony stimulating factor (anti-GM-CSF) antibody concentrations, the gold standard for diagnosis of pulmonary alveolar proteinosis, is not available in South Africa.