Churg-Strauss syndrome versus chronic eosinophilic pneumonia on high-resolution computed tomographic findings

Thoracic Manifestations of ANCA-associated Vasculitis: Review of the 2022 American College of Rheumatology-European Alliance of Associations of Rheumatology Classification Criteria

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a rare disease that manifests as necrotizing vasculitis involving small vessels without immune complex deposition. Granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and microscopic polyangiitis (MPA) are included in this disease entity. Diagnosis and differentiation of AAV is challenging because of the diverse and overlapping clinical manifestations and lack of pathognomonic findings. Therefore, AAV classification criteria have been developed to increase the likelihood of diagnosis using multidisciplinary approaches, including clinical, radiologic, laboratory, and pathologic findings. The new American College of Rheumatology and European Alliance of Associations for Rheumatology classification criteria were released in 2022 to classify AAVs using weighted criteria and threshold scores. They are expected to make the classification of GPA, EGPA, and MPA more accurate in the setting of suspected small-vessel vasculitis. The criteria present key thoracic imaging discriminators of GPA as "pulmonary nodules, masses, or cavitation" and MPA as "interstitial fibrosis," whereas, radiologic criteria of EGPA are not present. ANCA positivity and eosinophil count are included as key laboratory discriminators. It is essential for radiologists to familiarize themselves with imaging findings of each AAV and know the key imaging discriminators to aid in the differential diagnosis of AAVs. By reviewing the radiologic findings of thoracic manifestations of each AAV and applying the new criteria in a series of cases, the authors aim to provide a practical and stepwise approach to AAV for radiologists. ©RSNA, 2025 Supplemental material is available for this article.

Eosinophilic Lung Diseases

The eosinophilic lung diseases may manifest as chronic eosinophilic pneumonia, acute eosinophilic pneumonia, or as the Löffler syndrome (generally of parasitic etiology). The diagnosis of eosinophilic pneumonia is made when both characteristic clinical-imaging features and alveolar eosinophilia are present. Peripheral blood eosinophils are generally markedly elevated; however, eosinophilia may be absent at presentation. Lung biopsy is not indicated except in atypical cases after multidisciplinary discussion. The inquiry to possible causes (medications, toxic drugs, exposures, and infections especially parasitic) must be meticulous. Idiopathic acute eosinophilic pneumonia may be misdiagnosed as infectious pneumonia. Extrathoracic manifestations raise the suspicion of a systemic disease especially eosinophilic granulomatosis with polyangiitis. Airflow obstruction is frequent in allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, and hypereosinophilic obliterative bronchiolitis. Corticosteroids are the cornerstone of therapy, but relapses are common. Therapies targeting interleukin 5/interleukin-5 are increasingly used in eosinophilic lung diseases.

Predictive factors for relapse in corticosteroid-treated patients with chronic eosinophilic pneumonia

BACKGROUND

Chronic eosinophilic pneumonia (CEP) is an idiopathic disorder characterised by an abnormal and marked accumulation of eosinophils in the interstitium and alveolar spaces of the lungs. Systemic corticosteroid (CS) therapy leads to marked improvement. However, relapse is common in the clinical course, and the predictive factors for relapse of CEP are not well known. This study aimed to investigate predictive factors for relapse in CS-treated cases of CEP.

METHODS

We identified consecutive patients with CEP at our institution between 1999 and 2019. We retrospectively reviewed 36 CS-treated patients with CEP who underwent bronchoalveolar lavage (BAL) and high-resolution computed tomography (CT) at diagnosis. We examined relapse at least 1 year after the initiation of CS treatment. Statistical analysis included univariate and multivariate Cox proportional hazard regression analyses; P<0.05 was considered statistically significant.

RESULTS

The median (interquartile range) age at diagnosis was 59.5 years (47.8-70.0 years). This study included 13 men and 23 women. Twenty-five patients (69.4%) were never smokers and 15 (41.7%) had asthma. The peripheral blood eosinophil percentage was 35.0% (15.6-55.8%), and the BAL eosinophil percentage was 40.8% (10.7-68.5%). The median serum surfactant protein-D (SP-D) level was 135 ng/mL (82.2-176.7 ng/mL). High-resolution CT revealed centrilobular opacities in 23 patients (63.9%). Relapse of CEP was observed in 20 patients (55.6%). Higher serum SP-D levels and the presence of centrilobular opacities on high-resolution CT were significant predictors of relapse in multivariate Cox proportional hazard regression analysis (P=0.017 and P=0.028, respectively). Additionally, we devised a relapse prediction model for CS-treated CEP using two categorical parameters: the presence of centrilobular opacities and serum levels of SP-D (>135/≤135 ng/mL). Based on these parameters, cases were scored 2, 1, or 0. Patients with a score of 2 experienced relapses earlier than those with scores of 1 and 0 (log-rank test; P=0.006, P=0.003, respectively).

CONCLUSIONS

Centrilobular opacities on high-resolution CT and higher serum SP-D levels at diagnosis may be predictive factors for relapse in CS-treated patients with CEP.

Retrospective comparison of high-resolution computed tomography of eosinophilic granulomatosis with polyangiitis with severe asthma

Background

Eosinophilic granulomatosis with polyangiitis (EGPA) is often misdiagnosed as severe asthma due to their similar clinical presentations. We compared the pulmonary radiologic features of EGPA to those of severe asthma by high-resolution computed tomography (HRCT) in order to early diagnose EGPA.

Methods

We retrospectively reviewed clinical records and HRCT findings of 96 patients with EGPA and 82 patients with severe asthma who were seen at our hospital from 2011 to 2017. We used a semi-quantitative grading system to evaluate radiological findings. A radiological only and a clinical-radiological model were used to differentiate EGPA from severe asthma.

Results

Bronchial wall thickening, air trapping, tree-in-bud opacities, bronchial mucus plugging, bronchiectasis, diffuse ground-glass opacities (GGOs), consolidation, and increased small vascular markings were more common in EGPA patients than in severe asthmatics (P<0.05). The gradings of GGO (grade 2 vs. grade 1) and tree-in-bud opacities (grade 2 vs. grade 0) were higher in EGPA patients than in severe asthmatics. The total image score of EGPA patients was significantly higher than that of severe asthmatics (P<0.05). In the radiological only and the clinical-radiological model, the area under the receiver operating characteristic (ROC) curves (AUCs) for the identification of EGPA and severe asthma were 0.904 [95% confidence interval (CI): 0.860 to 0.948] and 0.974 (95% CI: 0.955 to 0.993), respectively.

Conclusions

Lung HRCT scan is useful in differentiating EGPA from severe asthma. In patients with difficult-to-treat asthma, an HRCT scan of the thorax should be performed should there be features that raise the suspicion of EGPA.

An unusual case of eosinophilic lung disease with multiple cyst formation

We report here an unusual case of eosinophilic necrotizing inflammation of the lung that mimicked chronic eosinophilic pneumonia. A 71-year-old man who lived in an unsanitary environment and was referred to our hospital with suspected pneumonia. Peripheral blood eosinophilia was observed, and computed tomography indicated extensive consolidation with multiple cystic lesions, mainly in the left lung. A histological analysis using video-assisted thoracic surgery revealed diffuse infiltration of inflammatory cells into the alveolar wall and massive accumulation of macrophages and eosinophils in the airspace. Many tiny eosinophilic abscesses were scattered through the tissue. These findings were more severe than those associated with chronic eosinophilic pneumonia. Immunostaining revealed the deposition of eosinophil granular protein and the presence of extracellular traps and Charcot–Leyden crystals, which suggested excessive eosinophil activation. Interestingly, the patient's symptoms and clinical findings gradually improved without treatment after admission. He was discharged to a clean residence and did not have a recurrence for 19 months. The observations suggest a hypersensitivity reaction to an environmental allergen and consequent multiple cyst formation in association with eosinophilic necrotizing inflammation, although further studies are warranted.

•

Formation of lung cysts is extremely rare in eosinophilic lung diseases.

•

Eosinophilic necrotizing inflammation may induce cyst formation.

•

This inflammation is associated with eosinophil extracellular trap cell death.

Eosinophilic pneumonia: A review of the previous literature, causes, diagnosis, and management

Eosinophilic pneumonia (EP) is a rare disorder, comprising several heterogeneous diseases. Two major types of EP are acute eosinophilic pneumonia (AEP) and chronic eosinophilic pneumonia (CEP), both of which are characterized by marked accumulation of eosinophils in lung tissues and/or BAL fluid. AEP and CEP share some similarities in terms of pathophysiology, radiological findings, and treatment response to corticosteroids. However, they distinctly differ in etiology, clinical manifestations, and the nature of disease course. Especially, although AEP and CEP respond well to corticosteroids, relapse frequently occurs in patients with CEP, but rarely in those with AEP. Although CEP occasionally persists and becomes corticosteroid dependent, most patients with AEP completely recover. This article reviews previous studies and discusses the etiology, clinical manifestations, and treatment of AEP and CEP.

Eosinophilic Lung Diseases

Eosinophilic lung diseases especially comprise eosinophilic pneumonia or as the more transient Löffler syndrome, which is most often due to parasitic infections. The diagnosis of eosinophilic pneumonia is based on characteristic clinical-imaging features and the demonstration of alveolar eosinophilia, defined as at least 25% eosinophils at BAL. Peripheral blood eosinophilia is common but may be absent at presentation in idiopathic acute eosinophilic pneumonia, which may be misdiagnosed as severe infectious pneumonia. All possible causes of eosinophilia, including drug, toxin, fungus related etiologies, must be thoroughly investigated. Extrathoracic manifestations should raise the suspicion of eosinophilic granulomatosis with polyangiitis.

Novel imaging approaches in adult asthma and their clinical potential

Currently, imaging in asthma is confined to chest radiography and CT. The emergence of new imaging techniques and tremendous improvement of existing imaging methods, primarily due to technological advancement, has completely changed its research and clinical prospects. In research, imaging in asthma is now being employed to provide quantitative assessment of morphology, function and pathogenic processes at the molecular level. The unique ability of imaging for non-invasive, repeated, quantitative, and in vivo assessment of structure and function in asthma could lead to identification of 'imaging biomarkers' with potential as outcome measures in future clinical trials. Emerging imaging techniques and their utility in the research and clinical setting is discussed in this review.

Efficacy of short-term prednisolone treatment in patients with chronic eosinophilic pneumonia

In patients with chronic eosinophilic pneumonia (CEP), dramatic improvements are seen in response to corticosteroid therapy; however, relapse is common after treatment has ceased. The optimal duration of corticosteroid therapy remains unclear.

In a randomised, open-label, parallel group study, eligible patients with CEP received oral prednisolone for either 3 months (3-month group) or 6 months (6-month group), followed by 2 years observation. All patients were treated with an initial dose of prednisolone of 0.5 mg·kg−1·day−1, which was then tapered and discontinued at either 3 or 6 months. The primary end-point was relapse during the follow-up period.

In the final analysis, there were 23 patients in the 3-month group and 21 patients in the 6-month group. All patients showed a good response to prednisolone treatment. There were 12 (52.1%) relapses in the 3-month group and 13 (61.9%) relapses in the 6-month group. No significant difference was found in the cumulative rate of relapse (p=0.56). All relapse cases showed improvement upon resumption of prednisolone treatment.

No difference was observed in the rate of relapse between the 3- and 6-month prednisolone treatment groups for patients with CEP.

Eosinophilic Pneumonia

Eosinophilic pneumonia may manifest as chronic or transient infiltrates with mild symptoms, chronic idiopathic eosinophilic pneumonia, or the frequently severe acute eosinophilic pneumonia that may be secondary to a variety of causes (drug intake, new onset of tobacco smoking, infection) and that may necessitate mechanical ventilation. When present, blood eosinophilia greater than 1 × 10⁹ eosinophils/L (and preferably greater than 1.5 × 10⁹/L) is of considerable help for suggesting the diagnosis, however it may be absent, as in the early phase of idiopathic acute eosinophilic pneumonia or when patients are already taking corticosteroids. On bronchoalveolar lavage, high eosinophilia (>25 %, and preferably >40 % of differential cell count) is considered diagnostic of eosinophilic pneumonia in a compatible setting, obviating the need of video-assisted thoracic surgical lung biopsy, which is now performed only on very rare occasions with inconsistency between clinical, biological, and imaging features. Inquiry as to drug intake must be meticulous (www.pneumotox.com) and any suspected drug should be withdrawn. Laboratory investigations for parasitic causes must take into account the travel history or residence and the epidemiology of parasites. In patients with associated extrathoracic manifestations, the diagnosis of eosinophilic granulomatosis with polyangiitis or of the hypereosinophilic syndromes should be raised. Presence of airflow obstruction can be found in hypereosinophilic asthma, allergic bronchopulmonary aspergillosis, idiopathic chronic eosinophilic pneumonia, eosinophilic granulomatosis with polyangiitis, or in the recently identified syndrome of hyperosinophilic obliterative bronchiolitis. Corticosteroids remain the cornerstone of symptomatic treatment for eosinophilic pneumonias, with a generally dramatic response. Relapses are common when tapering the doses or after stopping treatment especially in idiopathic chronic eosinophilic pneumonia. Cyclophosphamide is necessary only in patients with eosinophilic granulomatosis with polyangiitis and poor-prognostic factors. Imatinib is very effective in the treatment of the myeloproliferative variant of hypereosinophilic syndromes. Anti-interleukin-5 monoclonal antibodies are promising in the spectrum of eosinophilic disorders.

Systemic granulomatous diseases associated with multiple palpable masses that may involve the breast: case presentation and an approach to the differential diagnosis

Palpable mass is a common complaint presented to the breast surgeon. It is very uncommon for patients to report breast mass associated with palpable masses in other superficial structures. When these masses are related to systemic granulomatous diseases, the diagnosis and initiation of specific therapy can be challenging. The purpose of this paper is to report a case initially assessed by the breast surgeon and ultimately diagnosed as granulomatous variant of T-cell lymphoma, and discuss the main systemic granulomatous diseases associated with palpable masses involving the breast.

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss): evolutions in classification, etiopathogenesis, assessment and management

PURPOSE OF REVIEW

Eosinophilic granulomatosis with polyangiitis (EGPA) (Churg-Strauss syndrome) is a peculiar hybrid condition of a systemic antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and a hypereosinophilic disorder with frequent lung involvement that occurs in people with asthma. This review focuses on areas of evidence or persistent uncertainty in the classification, epidemiology, clinical presentation, diagnosis, prognosis and management of EGPA and attempts to identify clues to the mechanisms in the development or course of the disease.

RECENT FINDINGS

The 2013 revision of the EGPA definition formally placed the disease in the subset of ANCA-associated vasculitides. Recently published large case series underlined that the presence of ANCAs, found in 30-40% of EGPA, determines distinct but partly overlapping disease expression and the major detrimental effect of heart involvement on survival. There is some evidence that asthma in EGPA resembles a nonallergic eosinophilic asthma phenotype. Encouraging results have been reported for the treatment of EGPA with rituximab or with the eosinophil-targeted antiinterleukin-5 agent mepolizumab.

SUMMARY

The understanding of EGPA continues to advance, but many gaps in knowledge remain. The nomenclature remains a source of conceptual variance in terms of demonstrated presence or not of vessel inflammation or ANCAs in the diagnosis of EGPA. Distinguishing EGPA from hypereosinophilic syndromes can be problematic, and an understanding of the mechanistic relation between the vasculitis and the eosinophilic proliferation is profoundly lacking. Some evidence suggests distinct disease phenotypes, but this concept has not yet been translated to phenotype-adapted therapy.

Chronic Eosinophilic Pneumonia: A Pediatric Case with Idiopathic Bronchiectasis

Chronic eosinophilic pneumonia (CEP) is a rare lung disease and is especially uncommon in children. It presents with subacute respiratory symptoms of hypoxemia and dyspnea, peripheral infiltrates on imaging, and eosinophilia. However, it can be difficult to diagnose, as there is no strict diagnosis criteria and the clinical findings may be very nonspecific. In this case report, we describe a 14-year-old female with an unusual presentation of asymptomatic bronchiectasis, and the role of surgical lung biopsy in the diagnosis of CEP when no peripheral or alveolar eosinophilia is seen. It suggests that perhaps bronchiectasis can also be an unusual presenting sign of CEP and that there may be more asymptomatic cases of CEP with the true incidence being underreported, especially in the pediatric population.

Eosinophilic pneumonias

This review starts with discussions of several infectious causes of eosinophilic pneumonia, which are almost exclusively parasitic in nature. Pulmonary infections due specifically to Ascaris, hookworms, Strongyloides, Paragonimus, filariasis, and Toxocara are considered in detail. The discussion then moves to noninfectious causes of eosinophilic pulmonary infiltration, including allergic sensitization to Aspergillus, acute and chronic eosinophilic pneumonias, Churg-Strauss syndrome, hypereosinophilic syndromes, and pulmonary eosinophilia due to exposure to specific medications or toxins.

Delay in diagnosis of Churg-Strauss syndrome: a case report

Churg-Strauss syndrome (CSS) is a well established disorder of the blood vessels. However, it is still sometimes not diagnosed early enough to avoid serious complications. It is the later stage that carries the more serious complications. Therefore, we emphasize the ways in which the diagnosis can be made early enough to avoid this stage of the disease. We report a case of CSS that was not diagnosed early and so the patient went on to develop severe cardiac and neurological manifestations. In this report we discuss the techniques and the methods to diagnose CSS and discuss their effectiveness in establishing the diagnosis. We also explore late cardiac and neurological complications because these are particularly serious complications later in the disease. We conclude that the criteria established by the American College of Rheumatology for CSS is the best tool available for early diagnosis and that late stage manifestations of CSS carry high rates of morbidity and mortality.

Pathological and high resolution CT findings in Churg-Strauss syndrome

OBJECTIVE

To investigate the Churg-Strauss syndrome (CSS) associated lung involvement, concentrating on clinical characteristics, pathological findings of lung involvements, response to treatment, and prognosis.

METHODS

We retrospectively analyzed the characters of the clinical manifestations, thin-section CT and pathological findings of CSS. The study involved 16 patients. Clinical data were obtained by chart review. All patients underwent transbronchial lung biopsy (TBLB). Six of them underwent surgical lung biopsy as well.

RESULTS

The patients included 7 men and 9 women, aged from 14 to 61 years (median, 47.5 years). Extrathoracic organs involved included nervous system (7/16) and skin (5/16). Respiratory symptoms included cough (12/16), exertional dyspnea (11/16), hemoptysis (4/16), and chest pain (3/16). CT findings included bilateral ground-glass opacities (12/16), bilateral patchy opacities (12/16), and centrilobular nodules (6/16). The pathological findings of TBLB demonstrated increased eosinophils (3/16), vasculitis (3/16), and interstitial pneumonia (16/16). The pathological findings of surgical lung biopsy of 6 cases showed necrotizing vasculitis in 4 cases, capillaries in 5, eosinophilic pneumonia in 3, granulomas in 2, and airway abnormalities in 3. All patients improved in symptoms after therapy during the study period (range, 3 to 51 months; median, 15 months).

CONCLUSIONS

Asthma may be present in CSS patient when there is bronchial involvement. Ground-glass opacities and consolidation seen on high-resolution CT reflect the presence of eosinophilic pneumonia, vasculitis, and pulmonary alveolar hemorrhage. TBLB has significant limitations for the diagnosis of CSS. Early diagnosis and therapy can result in satisfactory prognosis.

Pulmonary findings in Churg-Strauss syndrome in chest X-rays and high resolution computed tomography at the time of initial diagnosis

Churg-Strauss syndrome (CSS) is a rare, systemic, necrotizing, small- and middle-sized vessel vasculitis which is accompanied by blood eosinophilia, eosinophil infiltration of various tissues, and bronchial asthma. The lungs are the organs most often involved in CSS. The aim of this study was a retrospective evaluation of the pulmonary findings in chest X-rays and high resolution computed tomography (HRCT) in CSS patients at the time of initial diagnosis and to determine their frequency, character, and location. Seventeen CSS patients were studied (12 women; 5 men; aged 29-56 years). In all patients at the time of initial diagnosis, chest X-rays were performed, and in 15 patients, HRCT was performed additionally. The radiological images were evaluated independently by two radiologists who reached a decision by consensus. Out of 17 patients studied, chest X-rays revealed parenchymal abnormalities in 11, pleural effusion in three, and bronchial wall thickening in one. In five patients, no abnormalities in chest X-rays were found. In HRCT, abnormalities were found in all patients (15 patients, 100%). Predominant HRCT findings consisted of: ground-glass opacities and consolidations found in 13 patients (86.7%). Additionally, in four patients, pulmonary micronodules were described; in ten, interlobular septal thickening; in three, linear opacities; in ten, bronchial wall thickening and/or bronchial dilatation; and in three, pleural effusions. Ground-glass opacities and consolidation abnormalities distribution pattern were peripheral in seven and random in six patients. In patients with CSS, the most common pulmonary radiological findings are parenchymal opacities, which may be peripheral or random in distribution. Pathologic changes were found in 70.6% of patient in chest X-rays, and in 100%, when HRCT was performed. These changes are nonspecific; however, they should be not overlooked, as they may help in establishing the diagnosis and suggest the prognosis.