Clinical History
A 65-year-old male patient was evaluated for a 3 months history of cough, fatigue and mild dyspnoea. The patient was a non-smoker and did not report drugs consumption. Blood tests revealed moderate peripheral eosinophilia. A chest-computed tomography (CT) was performed.
Imaging Findings
Chest CT revealed in the right upper lobe scattered subpleural areas of increased lung attenuation (ground-glass opacity) with superimposed interlobular septal thickening and intralobular lines, configuring a “crazy paving pattern” (Fig. 1, 2). There were no pleural effusion nor a mediastinal lymphadenopathy. The diagnostic suspicion of chronic eosinophilic pneumonia (CEP) was expressed.
The patient underwent bronchoscopy with analysis of the bronchio-alveolar lavage, revealing 40% eosinophils on differential cell count with an absence of infectious pathogens. Transbronchial biopsy showed a histological pattern consisting of thickened alveolar septa, with a remarkable accumulation of eosinophils and lymphocytes. These findings confirmed the diagnostic suspicion of CEP.
Following corticosteroid therapy, the patient’s symptom regressed and follow-up CT showed complete resolution of lung parenchymal abnormalities (Fig. 3).
Discussion
Chronic eosinophilic pneumonia (CEP), together with simple pulmonary eosinophilia (Loeffler syndrome), acute eosinophilic pneumonia and idiopathic hypereosinophilic syndrome, belongs to eosinophilic lung diseases of unknown cause, consisting of a group of pulmonary disorders associated with peripheral or tissue eosinophilia [1].
Eosinophilic lung diseases of known cause include allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis, parasitic infections, drug reactions, or vasculitis [1].
CEP was first described by Carrington in 1969 as a chronic form of Loeffler’s syndrome, which is a self-limiting disease characterized by areas of parenchymal consolidation that disappear within several days. The exact prevalence of CEP is unknown, however, it represents a rare disorder that often involves middle-aged patients and occurs more frequently in women [2, 3].
Clinical evaluation, laboratory tests and radiological appearance are synergetic in the diagnosis of CEP, which is based on the following criteria:
1) respiratory symptoms, such as dyspnoea and non-productive cough, often non-specific and developing insidiously with a duration of more than 2 weeks before the diagnosis is made; CEP may also manifest itself with general symptoms such as asthaenia, low-grade fever and weight loss [3];
2) blood eosinophilia, that may be mild, moderate, or severe, and alveolar eosinophilia, with BAL analysis typically revealing a very high percentage of eosinophils [1, 3];
3) radiological appearance consisting in peripheral pulmonary infiltrates, mainly involving the upper lobes. Chest radiographs may depict peripheral lung consolidations, but CT is a more sensible technique in evaluation of lung abnormalities. CT images usually show non-segmental areas of parenchymal consolidations with peripheral distribution and sometimes ground glass opacities with reticulation. Other radiological finding may be band-like opacities and, in 10% of cases, pleural effusion [1] The crazy paving pattern, which is recognized to be a manifestation of several pulmonary diseases, has been rarely described associated to CEP [4, 5];
4) exclusion of known causes of eosinophilic disease [1, 3].
Histology is usually not necessary for the definitive diagnosis and typically reveals interstitial and alveolar inflammation with a predominance of eosinophils.
CEP presents a good prognosis with regression after corticosteroid therapy; in fact, some authors have indicated the prompt response to steroid treatment to be a diagnostic criterion [3].
Our patient’s symptoms and peripheral eosinophilia, together with the radiological pattern consisting in peripheral location of findings and upper lobe involvement, allowed us to suspect CEP, even if the "crazy paving" pattern is not common in this disease.
Differential Diagnosis List
Chronic eosinophilic pneumonia with crazy paving pattern
Cryptogenic organizing pneumonia
Churg-Strauss syndrome
Loeffler syndrome
Final Diagnosis
Chronic eosinophilic pneumonia with crazy paving pattern
