Chronic Eosinophilic Pneumonia
Definition
- Chronic respiratory disorder associated with pulmonary eosinophil infiltration
Covered Separately
Diagnostic Criteria
Clinical
- Chronic dyspnea, cough
- Respiratory failure uncommon
- Weight loss, fever, night sweats common
- May have history of asthma, atopy
- Mean age 45
- Rapid response to steroids
- 50% relapse
X-ray
- Bilateral diffuse opacities with peripheral accentuation
- "Photographic negative of pulmonary edema" classic but seen in <50%
Pathology
- Hypereosinophilia must be demonstrated in the blood or lung to make the diagnosis
- Blood eosinophils usually >1000/mm3
- Steroid treament may dramatically reduce eosinophilia
- Bronchoalveolar lavage (BAL) fluid shows eosinophils > lymphocytes
- Usually >40%
- Tissue biopsy shows prominent eosinophilic infiltrate
- Biopsy is not usually necessary for diagnosis but may help rule out infection
- Intra-alveolar and usually interstitial
- May have eosinophilic microabscesses with central necrosis
- May invade vessel walls but no necrosis or granulomatous vasculitis
- 5-25% eosinophils is consistent with diagnosis, >25% is suggestive
- Eosinophils are rare in normal lung (<2%)
- Sarcoid like granulomas without necrosis may be present
- Organizing pneumonia may be present
- Blood eosinophils usually >1000/mm3
- Known causes must be ruled out
- Drugs including antibiotics, non-steroidal anti-inflammatory, anti-hypertensive, heroin, cocaine
- Organisms including fungi and parasites
- Allergic bronchopulmonary aspergillosis
Gerald J Berry MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
