대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Acute Eosinophilic Pneumonia

Radiologic Findings

Iniitial chest PA shows diffuse increased interstitial markings and reticular densities in both lungs without cardiomegaly. On next day, chest PA shows newly developed patchy nodular ground-glass opacities and some consolidations in both lungs. And reticular densities and increased interstitial markings are somewhat increased.

HRCT shows linear densities by diffuse smooth thickening of interlobular septa, and bilateral patchy ground-glass opacities and focal consolidation in both lungs. And there is small amount of bilateral pleural effusion, but cardiomegaly is not noted.

Clinically, dyspnea has rapidly aggravated. Arterial blood gas analysis showed hypoxia (PaO2 : 50mmHg, PaCO2 :35mmHg). And bronchoalveolar lavage (BAL) revealed severe increased eosinophil counts (eosinophil 50%).

Brief Review

Idiopathic acute eosinophilic pneumonia is a recently described clinicopathologic entity. The disease is characterized clinically by acute febrile illness lasting 1-5 days accompanied by myalgia, pleuritic chest pain, hypoxemic respiratory failure, often requiring mechanical ventilation. The disease is characterized pathologically by infiltration of eosinophils and mononuclear cells and by edema within the alveolar space, bronchial wall, and to a lesser degree, interstitial space and pleura.

Diagnostic criteria of acute eosinophilic pneumonia:
acute febrile illness of fewer than 5 days duration,
severe hypoxemia (PaO2<60mmHg on room air),
pulmonary abnormality visible on chest radiographs,
an increased percentage of eosinophils (>25%) on bronchoalveolar lavage fluid,
no pulmonary or systemic infection,
no history of asthma or other allergic disease,
a prompt and complete resolution with or without steroid treatment,
and follow-up studies showing the resolution of pulmonary eosinophilia.
Predominant radiographic finding was diffuse bilateral reticular densities (67%), and reticular densities were combined with parenchymal consolidation. Or isolated parenchymal consolidation was observed. Unilateral or bilateral pleural effusion was also seen.
The most common abnormality of CT scans were areas of ground-glass opacity. And areas of consolidation or areas of poorly defined nodules were also seen. Smooth interlobular septal thickening was another frequent CT finding.

Differential diagnosis includes overhydration pulmonary edema, adult respiratory distress syndrome, acute interstitial pneumonia, and atypical bacterial or viral pneumonia.

References

1. Cheon JE, Lee KS, Jung GS, Chung MH, Cho YD. Acute eosinophilic pneumonia: radiographic and CT findings in six patients. AJR 1996;167:1195-1199
2. King MA, Pope-Harman AL, Allen JN, Christoforidis GA, Christoforidis AJ. Acute eosinophilic pneumonia: radiologic and clinical features. Radiology:1997;203:715-719

Keywords

Lung, Eosinophilic lung disease,