Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Pulmonary Alveolar Proteinosis
- Radiologic Findings
- Chest PA radiograph shows ill-defined increased opacities in the right middle lung zone and the both lower lung zones.
Chest CT axial images(lung window setting) show ill-defined ground glass opacities with crazy-paving appearance and minimal traction bronchiectasis along the both lung central subpleural areas.
Fig.1. Photomicrograph of the right upper lobe lung tissue with H & E stain shows the accumulation of pinkish granular eosinophilic material(asterisk) within the alveoli. (H & E, 횞200)
Fig. 2. Immunohistochemistry; PAS(+), Congo-red (-)
Fig 1
Fig 2
- Brief Review
- Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by abnormal intraalveolar accumulation of surfactant-like material. Three distinct subgroups of PAP are currently recognized: idiopathic, secondary, and congenital.
Patients with idiopathic or secondary PAP experience nonspecific, moderate respiratory symptoms including progressive dyspnea and dry or minimally productive cough. Less common signs and symptoms include fatigue, weight loss, low-grade fever, chest pain, and hemoptysis.
Classic radiographic finding is a helpful first step in diagnostic imaging but remains nonspecific for PAP. The typical radiograph reveals bilateral central and symmetric lung opacities, with relative sparing of the apices and costophrenic angles.
The finding of CT is an appearance of 'crazy-paving' that defined as a network of smoothly thickened reticular lines superimposed on areas of ground-glass opacity. Areas of crazy-paving in PAP are typically widespread and bilateral, often with sharply marginated areas of geographic or lobular sparing. There are widely variable patterns of regional or zonal predominance, including symmetric or asymmetric apical, basilar, central, peripheral, lobar, or diffuse lung involvement. Although the CT finding of crazy-paving is highly characteristic of PAP, it is also seen in several infectious, hemorrhagic, neoplastic, inhalational, and idiopathic conditions as well as in straightforward hydrostatic pulmonary edema. Therefore, the radiologic differential diagnosis of crazy-paving is broad and includes left heart failure, pneumonia (especially pneumocystis pneumonia), alveolar hemorrhage, bronchoalveolar carcinoma, lymphangitic carcinomatosis, diffuse alveolar damage (adult respiratory distress syndrome), radiation- or drug-induced pneumonitis, hypersensitivity pneumonitis, and pulmonary veno-occlusive disease.
- References
- 1. Fraser and Pare's Diagnosis of Diseases of the Chest혻. 2000-2007
2. Aletta Ann Frazier, MD, Teri J. Franks, MD. From the Archives of the AFIP Pulmonary Alveolar Proteinosis. RadioGraphics 2008; 28:883-899
- Please refer to
- Case 692 Case 670 Case 624 Case 525 Case 505
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- Keywords
- Lung, Metabolic and storage lung disesae,