Wegener's granulomatosis in the chest: high-resolution CT findings

A Febrile 67-Year-Old Man With Pulmonary Consolidation and Contralateral Nodules

CASE PRESENTATION

A 67-year-old man who currently smoked (45 pack-years) was referred to the emergency department for fever and exacerbation of cough over the last week. The current illness began 1 month earlier with nonproductive cough and exertional dyspnea. He did not report anorexia, hemoptysis, or weight loss. Outpatient treatment with cefditoren and moxifloxacin did not improve his symptoms. No remarkable medical history was reported. The patient was admitted for further evaluation.

Chest and Chest Wall Manifestations in Rheumatic Diseases

Thoracic involvement is common in patients with rheumatic diseases, contributing to significant morbidity and mortality. Early detection and prompt treatment may prevent the establishment of irreversible changes, thus improving patients' outcomes. Imaging studies play a vital role in the early detection of chest and chest wall manifestations, especially in patients with subclinical disease. Familiarity with the frequently affected thoracic regions and their presentation on imaging is therefore essential for practicing radiologists to provide an accurate assessment of the disease burden and treatment response. This review summarizes the common and less well-known chest and chest wall imaging features of rheumatic diseases.

Imaging of Pulmonary Vasculitis

This review will describe various disease processes resulting in pulmonary vasculitis. The clinical and imaging findings in these diseases often overlap with diffuse alveolar hemorrhage secondary to pulmonary capillaritis, a common manifestation in many of these diseases. A multidisciplinary approach is important for the correct diagnosis of these diseases, and this review will highlight the important imaging findings that radiologists need to be aware of to aid in this diagnostic process.

Granulomatosis With Polyangiitis (GPA) Mimicking Metastatic Malignancy

Granulomatosis with polyangiitis is a rare vasculitis characterized by necrotizing granulomatous inflammation affecting small blood vessels. It often presents with pulmonary masses and nodules, mimicking malignancy in imaging studies. Distinguishing granulomatosis with polyangiitis from cancer is crucial due to differing treatment approaches and prognoses. We describe a 54-year-old male with granulomatosis with polyangiitis presenting with headache, bilateral ear discharge, cough, and weight loss. Imaging revealed metabolically active lesions in the lungs and nasopharynx, initially suggestive of metastatic malignancy. Biopsies from the lung and nasopharyngeal lesions showed necrotizing granulomatous vasculitis, which was suggestive of granulomatosis with polyangiitis. Serological testing was positive for cytoplasmic antineutrophil cytoplasmic antibodies (c-ANCA) with elevated proteinase 3 (PR3) antibodies. This case underscores the diagnostic challenges of granulomatosis with polyangiitis, which can mimic malignancy radiologically. Early recognition and treatment initiation are pivotal in improving patient outcomes and preventing organ damage in granulomatosis with polyangiitis.

Granulomatosis with polyangiitis: clinical characteristics and updates in diagnosis

Granulomatosis with polyangiitis (GPA) is a rare systemic disease characterized by granulomatous inflammation of the respiratory tract and necrotizing vasculitis of small and medium vessels often associated with the production of anti-neutrophil cytoplasmic antibodies (ANCA) directed mainly against leukocyte proteinase 3 (PR3). Usually, it involves upper airways, lungs, and kidneys, however any organ may be affected. The diagnosis is based on clinical, radiological, and serological findings. Biopsies, although strongly recommended, are not always feasible and often provides non-specific features. ANCA plays a crucial role in the diagnosis of GPA; nevertheless, ANCA detection is not a substitute for biopsy, which plays an important role in suspected cases, particularly when histological confirmation cannot be obtained. Significant advances have been made in classification criteria and phenotyping of the disease, particularly in determining the nuances between PR3-ANCA and myeloperoxidase (MPO)-ANCA vasculitis. This has led to better characterization of patients and the development of targeted treatment in the future. In addition, better identification of cytokine and immunological profiles may result in immuno-phenotyping becoming a new approach to identify patients with ANCA-associated vasculitis (AAV). Due to the chronic relapsing-remitting nature, strict follow-up of GPA is necessary to provide appropriate management. The search for the accurate marker of disease activity and to predict relapse is still ongoing and no predictor has been found to reliably guide therapeutic decision-making.

Uncommon Causes of Interlobular Septal Thickening on CT Images and Their Distinguishing Features

Interlobular septa thickening (ILST) is a common and easily recognized feature on computed tomography (CT) images in many lung disorders. ILST thickening can be smooth (most common), nodular, or irregular. Smooth ILST can be seen in pulmonary edema, pulmonary alveolar proteinosis, and lymphangitic spread of tumors. Nodular ILST can be seen in the lymphangitic spread of tumors, sarcoidosis, and silicosis. Irregular ILST is a finding suggestive of interstitial fibrosis, which is a common finding in fibrotic lung diseases, including sarcoidosis and usual interstitial pneumonia. Pulmonary edema and lymphangitic spread of tumors are the commonly encountered causes of ILST. It is important to narrow down the differential diagnosis as much as possible by assessing the appearance and distribution of ILST, as well as other pulmonary and extrapulmonary findings. This review will focus on the CT characterization of the secondary pulmonary lobule and ILST. Various uncommon causes of ILST will be discussed, including infections, interstitial pneumonia, depositional/infiltrative conditions, inhalational disorders, malignancies, congenital/inherited conditions, and iatrogenic causes. Awareness of the imaging appearance and various causes of ILST allows for a systematic approach, which is important for a timely diagnosis. This study highlights the importance of a structured approach to CT scan analysis that considers ILST characteristics, associated findings, and differential diagnostic considerations to facilitate accurate diagnoses.

Clinical features and outcomes of small airway disease in ANCA-associated vasculitis

BACKGROUND AND OBJECTIVE

To clarify the prevalence, features and outcomes of small airway disease (SAD) in a Chinese cohort with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) related pulmonary involvement.

METHODS

SAD was recorded when the manifestations of either centrilobular nodules or air trapping were observed according to CT scans, except for infection or other airway-related comorbidities. Baseline and follow-up data were collected retrospectively.

RESULTS

Of the 359 newly diagnosed AAV patients with pulmonary involvement, 92 (25.6%) had SAD, including 79 (85.9%) cases of anti-MPO-ANCA positive, 9 (9.8%) cases of anti-PR3-ANCA positive and 2 (2.2%) cases of double positive. Patients with SAD were more likely to be younger, female, non-smokers, have more ear-nose-throat (ENT) involvement, and have higher baseline Birmingham Vasculitis Activity Score (BVAS) compared to patients without SAD. Several AAV-related SAD patients have improved lung function and CT scans after immunosuppressive therapy. Patients with SAD had a better prognosis compared to those without SAD. When dividing all patients into three groups: isolated SAD (only small airway involvements), SAD with other lower airway involvements, and non-SAD, patients in the SAD with other lower airway involvements group had the highest risk of infection, while patients in the non-SAD group had the worst long-term outcomes. Similar results were observed in anti-MPO-ANCA positive patients when performing subgroup analyses.

CONCLUSION

SAD is a unique manifestation of AAV-related lung involvement and exhibits distinct clinical features. It is vital to focus on SAD because of its association with prognosis and infection in AAV patients, especially in anti-MPO-ANCA positive patients. Moreover, SAD might represent a better response to immunosuppressors.

Subglottic Stenosis as a Presentation of Antineutrophil Cytoplasmic Antibody-Associated Glomerulonephritis

Granulomatosis with polyangiitis (GPA), previously Wegener's granulomatosis, is a necrotizing vasculitic disease process affecting the small- and medium-sized blood vessels. GPA is frequently associated with damage to the respiratory tract and kidneys but often affects other organ systems including the eyes, nasopharynx, and nervous system. Due to the vague nature of presenting symptoms and the progressive nature of GPA, it is essential to keep a broad differential to mitigate the high morbidity and mortality associated with the disease. Here we introduce a case of a GPA presenting as respiratory distress, stridor, and renal injury. We also review common clinical presentations, diagnostic evaluation, and treatment options.

Tips and Tricks in Thoracic Radiology for Beginners: A Findings-Based Approach

This review has the purpose of illustrating schematically and comprehensively the key concepts for the beginner who approaches chest radiology for the first time. The approach to thoracic imaging may be challenging for the beginner due to the wide spectrum of diseases, their overlap, and the complexity of radiological findings. The first step consists of the proper assessment of the basic imaging findings. This review is divided into three main districts (mediastinum, pleura, focal and diffuse diseases of the lung parenchyma): the main findings will be discussed in a clinical scenario. Radiological tips and tricks, and relative clinical background, will be provided to orient the beginner toward the differential diagnoses of the main thoracic diseases.

Endemic mycoses in children in North America: a review of radiologic findings

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Examination of nailfold videocapillaroscopy findings in ANCA-associated vasculitis

OBJECTIVE

The objective of this study was to evaluate nailfold videocapillaroscopy (NVC) as a useful tool for assessing the disease activity of ANCA-associated vasculitis (AAV).

METHODS

This study enrolled 51 patients with AAV and 21 healthy controls. We scored NVC findings semiquantitatively, and compared them between AAV patients and controls. We examined the association of NVC findings with disease activity indicators, histopathological findings of skin biopsies, and high-resolution CT (HRCT) scores in AAV. Additionally, we repeatedly rated the NVC findings 3 months after immunosuppressive therapy.

RESULTS

Of the 51 enrolled patients, 36 (70.6%) showed a microangiopathy pattern and 4 (7.8%) showed a scleroderma pattern in AAV. The scores for microhaemorrhage, capillary loss, neoangiogenesis, and tortuosity were significantly higher in the AAV group than in the control group. NVC abnormalities correlated with the severity of skin, lung and kidney involvement. The scores of giant capillaries significantly correlated with the total BVAS and the chest BVAS; the scores of capillary loss correlated with the chest BVAS and the renal BVAS. The scores of microhaemorrhage significantly correlated with perivascular inflammatory cell infiltrations in the upper dermis of the purpura and tended to correlate with the total ground-glass opacity and consolidation scores on HRCT. In addition, capillary loss scores had a significant positive correlation with serum creatinine levels. Additionally, the microhaemorrhage scores were significantly reduced after 3 months of immunosuppressive therapy.

CONCLUSION

In AAV patients, NVC abnormalities are significantly associated with disease severity. This result suggests that NVC is a useful tool for assessing the disease activity and treatment response in AAV.

A Diagnostic Dilemma of a Case of Granulomatosis With Polyangiitis (GPA) Presenting With Thrombotic Vasculopathy

Granulomatosis with polyangiitis (GPA) is a rare disease with a prevalence of about three in 100,000 persons in the United States. GPA is an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis affecting predominantly small-sized vessels. It can present with localized or systemic symptoms with multiple organ involvement, thus making diagnosis challenging. Common skin lesions in GPA are palpable purpura, petechiae, ulcers, and livedo reticularis. These lesions usually have underlying vasculitis with or without granuloma on histology findings. To date, there have been no previous reports about thrombotic vasculopathy in GPA before. We present a case of a 25-year-old female who presented with intermittent joint pain for weeks, purpuric rash, and mild hemoptysis for a few days. A review of systems was notable for a 15-pound weight loss in one year. Physical examination was significant for a purpuric rash on the left elbow and toe, and left knee swelling and erythema. Presenting laboratory results were notable for anemia, indirect hyperbilirubinemia, mildly elevated D-dimers, and microscopic hematuria. Chest radiograph revealed confluent airspace disease. Extensive infectious workup was negative. A skin biopsy of her left toe revealed dermal intravascular thrombi without evidence of vasculitis. The thrombotic vasculopathy did not favor vasculitis but raised concern for a hypercoagulable state. However, extensive hematologic workup was negative. Bronchoscopy findings were consistent with diffuse alveolar hemorrhage. Later, cytoplasmic ANCA (c-ANCA) and anti-proteinase 3 (PR3) antibody titers were positive. Her diagnosis was unclear since both skin biopsy and bronchoscopy were nonspecific and inconsistent with her positive antibody results. The patient eventually underwent a kidney biopsy, which showed pauci-immune necrotizing and crescentic glomerulonephritis. Finally, a diagnosis of granulomatosis with polyangiitis was made based on the kidney biopsy and positive c-ANCA. The patient was treated with steroids and IV rituximab and discharged home with outpatient rheumatology follow-up. Due to multiple signs and symptoms including thrombotic vasculopathy, there was a diagnostic dilemma requiring a multidisciplinary approach. This case highlights the importance of pattern recognition for the diagnostic framework of rare disease entities and the multidisciplinary collaborative efforts required to reach the final diagnosis.

Differentiating tracheobronchial involvement in granulomatosis with polyangiitis and relapsing polychondritis on chest CT: a cohort study

Background

In patients with tracheobronchial involvement, the differential diagnosis between granulomatosis with polyangiitis (GPA) and relapsing polychondritis (RP) can be challenging. The aim of this study was to describe the characteristics of airway abnormalities on chest computed tomography (CT) in patients with GPA or RP and to determine whether specific imaging criteria could be used to differentiate them.

Methods

GPA and RP patients with tracheobronchial involvement referred to a national referral center from 2008 to 2020 were evaluated. Their chest CT images were reviewed by two radiologists who were blinded to the final diagnosis in order to analyze the characteristics of airway involvement. The association between imaging features and a diagnosis of GPA rather than RP was analyzed using a generalized linear regression model.

Results

Chest CTs from 26 GPA and 19 RP patients were analyzed. Involvement of the subglottic trachea (odds ratio for GPA=28.56 [95% CI: 3.17; 847.63]; P=0.001) and extensive airway involvement (odds ratio for GPA=0.02 [95% CI: 0.00; 0.43]; P=0.008) were the two independent CT features that differentiated GPA from RP in multivariate analysis. Tracheal thickening sparing the posterior membrane was significantly associated to RP (odds ratio for GPA=0.09 [95% CI: 0.02; 0.39]; P=0.003) but only in the univariate analysis and suffered from only moderate interobserver agreement (kappa=0.55). Tracheal calcifications were also associated with RP only in the univariate analysis (odds ratio for GPA=0.21 [95% CI: 0.05; 0.78]; P=0.045).

Conclusion

The presence of subglottic involvement and diffuse airway involvement are the two most relevant criteria in differentiating between GPA and RP on chest CT. Although generally considered to be a highly suggestive sign of RP, posterior tracheal membrane sparing is a nonspecific and an overly subjective sign.

• The presence of subglottic involvement is in favor of GPA.

• Extensive airway involvement is in favor of RP.

• Posterior tracheal membrane sparing is a nonspecific and an overly subjective sign.

Granulomatosis with polyangiitis: Common and uncommon presentations

Granulomatosis with polyangiitis (GPA) is a multisystemic autoimmune small vessel vasculitis predominantly affecting the respiratory and renal systems. Other systems such as the central nervous system, orbital, cardiac and gastrointestinal systems may also be involved to a lesser degree. Although there are no imaging features that are pathognomonic for GPA, there are known radiological patterns suggestive of the disease and imaging plays an important role in diagnosis, assessment and monitoring of disease activity. This is more evident when combined with clinical features, biochemical values and histopathology results. This pictorial review aims to present both common and uncommon radiological features of GPA.

Imaging of intestinal vasculitis focusing on MR and CT enterography: a two-way street between radiologic findings and clinical data

Diagnosis of intestinal vasculitis is often challenging due to the non-specific clinical and imaging findings. Vasculitides with gastrointestinal (GI) manifestations are rare, but their diagnosis holds immense significance as late or missed recognition can result in high mortality rates. Given the resemblance of radiologic findings with some other entities, GI vasculitis is often overlooked on small bowel studies done using computed tomography/magnetic resonance enterography (CTE/MRE). Hereon, we reviewed radiologic findings of vasculitis with gastrointestinal involvement on CTE and MRE. The variety of findings on MRE/CTE depend upon the size of the involved vessels. Signs of intestinal ischemia, e.g., mural thickening, submucosal edema, mural hyperenhancement, and restricted diffusion on diffusion-weighted imaging, are common in intestinal vasculitis. Involvement of the abdominal aorta and the major visceral arteries is presented as concentric mural thickening, transmural calcification, luminal stenosis, occlusion, aneurysmal changes, and collateral vessels. Such findings can be observed particularly in large- and medium-vessel vasculitis. The presence of extra-intestinal findings, including within the liver, kidneys, or spleen in the form of focal areas of infarction or heterogeneous enhancement due to microvascular involvement, can be another radiologic clue in diagnosis of vasculitis. The link between the clinical/laboratory findings and MRE/CTE abnormalities needs to be corresponded when it comes to the diagnosis of intestinal vasculitis.

ANCA Associated Vasculitis (AAV): A Review for Internists

Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) compromise a rare group of necrotizing small to medium vessel vasculitides that constitute three distinct disorders: granulomatosis with polyangiitis (GPA) (formerly known as Wegener's granulomatosis), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA) (formerly known as Churg-Strauss syndrome).AAV is characterized by the usual presence of circulating autoantibodies to the neutrophil proteins leukocyte proteinase 3 (PR3-ANCA) or myeloperoxidase (MPO-ANCA). These antibodies can activate neutrophils and the complement system resulting in vessel wall inflammation and damage.The clinical presentation of AAV varies from non-severe (non-life threatening) to severe often with potentially life-threatening multi-organ involvement. Early recognition and diagnosis are crucial. In the past two decades, advances in understanding the pathophysiology of AAV have led to development of new treatments and resulted in significant improvement in general outcomes and survival rates.This narrative review will focus on GPA and MPA. We will highlight clinical manifestations, diagnosis, disease monitoring, and treatment strategies in patients with AAV.

Pulmonary involvement of ANCA-associated vasculitis in adult Chinese patients

Objective

The aim of this study was to clarify the clinical characteristics and long-term outcomes of ANCA-associated vasculitis (AAV) patients with pulmonary involvement from a single Chinese cohort.

Methods

Newly diagnosed AAV patients with pulmonary involvement, as defined by CT, were recruited from January 2010 to June 2020. Clinical data and CT images were collected retrospectively. Baseline CTs were evaluated and re-classified into four categories: interstitial lung disease (ILD), airway involvement (AI), alveolar hemorrhage (AH), and pulmonary granuloma (PG).

Results

A total of 719 patients were newly diagnosed with AAV, 366 (50.9%) of whom combined with pulmonary involvement at baseline. Among the AAV cases with pulmonary involvement, 55.7% (204/366) had ILD, 16.7% (61/366) had AI alone, 14.8% (54/366) had PG, and 12.8% (47/366) had AH alone. During follow-up of a median duration of 42.0 months, 66/366 (18.0%) patients died, mainly died from infections. Survival, relapse, and infection were all significantly different based on the radiological features. Specifically, the ILD group tends to have a poor long-term prognosis, the PG group is prone to relapse, and the AI group is apt to infection. The AH group has a high risk of both early infection and relapse, thus a poor short-term prognosis.

Conclusion

AAV patients with diverse radiological features have different clinical characteristics and outcomes. Therefore, the intensity of immunosuppressive therapy must be carefully valued by considering the baseline CT findings among AAV patients with pulmonary involvement.

FDG-Avid Tracheal Mass and Cartilage Involvements in ANCA-Negative Granulomatosis With Polyangiitis

ABSTRACT

A 57-year-old woman was referred for progressive dyspnea. CT showed a tracheal mass, suspicious of tracheal neoplasm. The lesion was partially resected, and nonspecific granulation tissue was observed on histology. Her symptoms and CT findings worsened. FDG PET/CT showed increased FDG accumulation in the nasal septum and left eustachian tube in addition to the tracheobronchial lesions. Although the patient was ANCA (antineutrophil cytoplasmic antibodies) negative, a differential diagnosis of granulomatosis with polyangiitis was established and confirmed pathologically. FDG PET/CT was useful for diagnosis of ANCA-negative granulomatosis with polyangiitis, in which tracheobronchial and cartilage lesions were prominent.

Breast involvement in granulomatosis with polyangiitis: a case report

Background

Granulomatosis with polyangiitis (GPA) previously known as Wegener's granulomatosis is a rare complex immune-mediated disease and a multisystem disorder with varying presentations where many of the imaging features of GPA overlap with those of other diseases, and hence its diagnosis can be challenging.

Case presentation

Here we report a case of a 48-year-old female who presented with complaints of hemoptysis, difficulty in speech, bilateral progressive hearing loss and, a palpable lump in the right breast. The case was initially misdiagnosed as breast carcinoma but biopsy proved to be GPA. Here we present the multisystem manifestations of GPA involving the head and neck, breast, lungs, spleen with involvement of the breast being very rare. The breast lesion showed improvement with steroids on follow-up.

Conclusions

GPA is a multisystem disease and though breast lesions in GPA are rare, a thorough knowledge about this uncommon manifestation is required and clinical, radiological, and histopathological correlation is of utmost importance in the evaluation of a breast lesion in cases of multisystem involvement to avoid unnecessary surgeries. The differential diagnosis of breast tumors should include such rare conditions that can sometimes mimic breast cancer. Early diagnosis and initiation of the immunosuppressive treatment help in a better prognosis of the disease.

From Head to Toe: Granulomatosis with Polyangiitis

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated vasculitis. It is an uncommon multisystem disease involving predominantly small vessels and is characterized by granulomatous inflammation, pauci-immune necrotizing glomerulonephritis, and vasculitis. GPA can involve virtually any organ. Clinical manifestations are heterogeneous and can be classified as granulomatous (eg, ear, nose, and throat disease; lung nodules or masses; retro-orbital tumors; pachymeningitis) or vasculitic (eg, glomerulonephritis, alveolar hemorrhage, mononeuritis multiplex, scleritis). The diagnosis of GPA relies on a combination of clinical findings, imaging study results, laboratory test results, serologic markers, and histopathologic results. Radiology has a crucial role in the diagnosis and follow-up of patients with GPA. CT and MRI are the primary imaging modalities used to evaluate GPA manifestations, allowing the differentiation of GPA from other diseases that could simulate GPA. The authors review the main clinical, histopathologic, and imaging features of GPA to address the differential diagnosis in the affected organs and provide a panoramic picture of the protean manifestations of this infrequent disease. The heterogeneous manifestations of GPA pose a significant challenge in the diagnosis of this rare condition. By recognizing the common and unusual imaging findings, radiologists play an important role in the diagnosis and follow-up of patients with GPA and aid clinicians in the differentiation of disease activity versus disease-induced damage, which ultimately affects therapeutic decisions. Online supplemental material is available for this article. ^©RSNA, 2021.

Myeloperoxidase and associated lung disease: Review of the latest developments

Myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibodies (ANCA) are often detected in association with a variety of lung pathologies, the most common being interstitial lung disease (ILD). A growing cohort of patients are being diagnosed with MPO-ANCA in the context of ILD without ANCA-associated vasculitis. Clinically and radiologically, there is little to differentiate this cohort from MPO-ANCA-negative ILD patients; however, the pathophysiology is likely different and different treatments are likely required. We present here a brief summary of the proposed pathophysiology of MPO-ANCA-positive ILD, and a more detailed review of the latest evidence on management, including monitoring for development of ANCA-associated vasculitis, immunosuppression, anti-fibrotics, and novel agents that have yet to be trialled in human experiments.

A case of granulomatosis with polyangiitis mimicking lung malignancy

Patients with granulomatosis with polyangiitis (GPA) may present with varied manifestations including pulmonary masses and nodules. We report the case of a 45-year-old man presenting with cough, haemoptysis and weight loss in the context of a 20 pack-year past smoking history. Computed tomography (CT) of the chest and positron emission tomography/CT scan demonstrated two right upper lobe masses, bilateral lung nodules and mediastinal lymphadenopathy, with increased fluorodeoxyglucose avidity. Endobronchial and CT-guided lung biopsy demonstrated granulomatous inflammation and elevated c-ANCA/PR3 confirmed the diagnosis of GPA. The patient received induction therapy with methylprednisolone and rituximab with good clinical response. Our case highlights the importance of considering a wide range of differentials in patients with lung masses/nodules, including autoimmune pathologies.

CT findings of non-neoplastic central airways diseases

Non-neoplastic lesions of central airways are uncommon entities with different etiologies, with either focal or diffuse involvement of the tracheobronchial tree. Clinical symptoms of non-neoplastic tracheobronchial diseases are non-specific, and diagnosis is difficult, especially in the early stages. Three-dimensional computed tomography (3D-CT) is an evaluable tool as it allows to assess and characterize tracheobronchial wall lesions and meanwhile it enables the evaluation of airways surrounding structures. Multiplanar reconstructions (MPR), minimum intensity projections (MinIP), and 3D Volume Rendering (VR) (in particular, virtual bronchoscopy) also provide information on the site and of the length of airway alterations. This review will be discussed about (1) primary airway disorders, such as relapsing polychondritis, tracheobronchophathia osteochondroplastica, and tracheobronchomegaly, (2) airway diseases, related to granulomatosis with polyangiitis, Chron's disease, Behcet's disease, sarcoidosis, amyloidosis, infections, intubation and transplantation, (3) tracheobronchial malacia, and (4) acute tracheobronchial injury. 3D-CT findings, especially with MPR and 3D VR reconstructions, allows us to evaluate tracheobronchial disease morphologically in detail.

A Tale of Two Organ Systems: Imaging review of diseases affecting the thoracic and neurological systems. Part 1

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurological systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated / inflammatory, vascular, syndromic / hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Non-Infectious Granulomatous Lung Disease: Imaging Findings with Pathologic Correlation

Non-infectious granulomatous lung disease represents a diverse group of disorders characterized by pulmonary opacities associated with granulomatous inflammation, a relatively nonspecific finding commonly encountered by pathologists. Some lesions may present a diagnostic challenge because of nonspecific imaging features; however, recognition of the various imaging manifestations of these disorders in conjunction with patients' clinical history, such as age, symptom onset and duration, immune status, and presence of asthma or cutaneous lesions, is imperative for narrowing the differential diagnosis and determining appropriate management of this rare group of disorders. In this pictorial review, we describe the pathologic findings of various non-infectious granulomatous lung diseases as well as the radiologic features and high-resolution computed tomography imaging features.

Rare pulmonary tumors and carcinoma mimickers; experience from an interventional radiology unit with radiologic-pathologic correlation-A pictoral essay

BACKGROUND

Although imaging findings along with patients' clinical history may give clue for the etiology of a pulmonary lesion, the differentiation of benign pulmonary lesions from lung cancer could be challenging.

OBJECTIVE

The aim of this review article was to increase the awareness of the carcinoma mimicking lung lesions.

METHODS

This paper was designed to illustrate rare pulmonary tumors and carcinoma mimickers with emphasis on radiologic-pathologic correlation. Pitfalls encountered on CT images and also false positivity of PET-CT scans were also presented.

CONCLUSION

Several benign pulmonary lesions may grow in size on follow-up and some may show pathologic FDG (18F-fluorodeoxyglucose) uptake, which makes them indistinguishable from lung carcinoma by imaging. In addition, some slow-growing malignant lesions, such as carcinoid, may be false-negative on PET/CT scans.

A 39-Year-Old Woman With Hemoptysis, Polydipsia, and Polyuria

CASE PRESENTATION

A 39-year-old previously healthy woman presented to the hospital with a nonproductive cough, small-volume hemoptysis, and exertional dyspnea. In addition, she reported a 4-week history of progressive left-sided headache, retro-orbital pain, left ear conductive hearing loss, fever, chills, anorexia, and a 10-lb weight loss. She had no prior sick contacts or history of respiratory tract infections. She did not take any chronic medications or supplements. The patient was a lifelong nonsmoker. She worked as a field consultant in Northern Manitoba communities. While in the hospital, she developed new symptoms of "unquenchable thirst," polydipsia, and polyuria.

Thoracic imaging finding of rheumatic diseases

In the era of Precision Medicine, diagnostic imaging plays a key role in initial diagnosis and treatment response assessment in thoracic manifestation of various rheumatic disorders; resulting in increased dependency on imaging for treatment planning. Chest radiographs serve as a good initial screening tool for assessment of emergent and urgent thoracic conditions, e.g., pneumothorax, pulmonary edema, consolidation and pleural effusions. Cross-sectional imaging techniques, e.g., computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) are most commonly utilized to evaluate more detailed pulmonary and mediastinal manifestations of rheumatic conditions. Magnetic resonance imaging (MRI) and ultrasound are most commonly used in cardiovascular, neural and musculoskeletal structures. This review article aims to highly key common thoracic imaging findings of rheumatic disorders, highlighting imaging test of choice for the particular disorder.

Multiple patchy pulmonary consolidation in granulomatosis with polyangiitis

Multiple patchy pulmonary consolidations that are unresponsive to antibiotics and/or exist at peri‐bronchial sites and bloody bronchoalveolar lavage may effectively help clinicians diagnose granulomatosis with polyangiitis.

Radiological approach to cavitary lung lesions

Cavitary lesions in the lung are not an uncommon imaging encounter and carry a broad differential diagnosis that includes a wide range of pathological conditions from cancers, infections/inflammatory processes to traumatic and congenital lung abnormalities. In this review article, we describe a comprehensive approach for evaluation of cavitary lung lesions and discuss the differential diagnosis in the light of radiological findings.

Lung Masses of Unusual Histologies Mimicking Malignancy: Flurodeoxyglucose Positron Emission Tomography-Computed Tomography Appearance

18F flurodeoxyglucose positron emission tomography-computed tomography (18F FDG PET-CT) is widely used in the evaluation of patients with lung mass suspicious for malignancy. In addition to malignancy, a variety of benign neoplasms and inflammatory lesions can arise in the lungs, many of which show increased FDG concentration, thereby mimicking malignancy. Awareness of the common mimics of lung cancer and a thorough understanding of their key imaging characteristics on CT as well as FDG PET is helpful in narrowing the differential diagnosis, eventually leading to appropriate therapy. In this article, we enlist these mimics and discuss their metabolic and morphologic characteristics and provide a pathophysiological basis for their FDG uptake.

Chronic Airspace Diseases

Airspace disease can be acute or chronic and commonly present as consolidation or ground-glass opacity on chest imaging. Consolidation or ground-glass opacity occurs when alveolar air is replaced by fluid, pus, blood, cells, or other material. Airspace disease is considered chronic when it persists beyond 4-6 weeks after treatment. These can be secondary to certain infectious, inflammatory, or neoplastic conditions. Computed tomography of the chest is usually performed in this set of patients to identify characteristic imaging findings. Familiarity with the differential diagnosis and characteristic imaging findings for chronic airspace disease is very important for guiding patient's management in a timely fashion.

Pulmonary vasculitis: diagnosis and endovascular therapy

Pulmonary vasculitides are caused by a heterogeneous group of diseases with different clinical features and etiologies. Radiologic manifestations depend on the predominant type of vessel involved, which are grouped into large, medium, or small-sized vessels. Diagnosing pulmonary vasculitides is a challenging task, and radiologists play an important role in their management by providing supportive evidence for diagnosis and opportunities for minimally invasive therapy. This paper aims to present a practical approach for understanding the vasculitides that can affect the pulmonary vessels and lungs. We will describe and illustrate the main radiologic findings, discussing opportunities for minimally invasive treatment.

Thoracic manifestation of Wegener's granulomatosis: Computed tomography findings and analysis of misdiagnosis

The aim of the present study was to investigate the computed tomography (CT) manifestations of Wegener granulomatosis (WG) in the chest and potential reasons for misdiagnosis. Conventional CT scans and clinical data of 45 patients with WG were retrospectively analyzed. Patients typically presented with multiple system involvement, primarily in the upper and lower respiratory tract. The incidence of thoracic involvement was 75.56% (34/45). Radiographic features were varied between cases in the present study, with the most common features being numerous cavitary nodules and masses in the lungs. Cavitations were usually irregular, with uneven wall thickness, partial centrality, fuzzy inner edges and piecemeal necrosis. These results indicate that WG typically has multiple system involvement, with the chest being most prominent. Multiple variable-sized cavitary nodules with irregular edges and piecemeal necrosis were the most notable features revealed using CT scanning; however, in order to give a definitive diagnosis, biopsies should be performed.

Risk factors and treatment of pneumothorax secondary to granulomatosis with polyangiitis: a clinical analysis of 25 cases

Objectives

To investigate the risk factors and treatment strategies for pneumothorax secondary to granulomatosis with polyangiitis (GPA).

Method

Retrospective analysis of cases with pneumothorax secondary to GPA from our own practice and published on literature.

Results

A total of 25 patients, 18 males and 7 females, mean age 44 ± 15.7 years, were analyzed. Diagnosis included pneumothorax (11 cases), hydropneumothorax (n = 5), empyema (n = 8) and hemopneumothorax (n = 1). 88% (22/25) patients showed single/multiple pulmonary/ subpleural nodules with/without cavitation on chest imaging. Erythrocyte sedimentation rate and C-reactive protein were both elevated. Corticosteroids and immunosuppressive agents were used in 16 cases. Five cases received steroid pulse therapy, of which 4 patients survived. Pleural drainage was effective in some patients. Seven patients underwent surgical operations. In the 10 fatal cases, infection and respiratory failure were the most common cause. Lung biopsy/ autopsy showed lung/pleural necrotizing granulomatous vasculitis, breaking into the chest cavity, pleural fibrosis, bronchial pleural fistula, etc. The mean age in the death group was greater than the survival group (53 ± 12.9 years vs 40.1 ± 14.7 years, p = 0.05), the ineffective pleural drainage was also higher in the death group (5/5 vs 0/7, p = 0.01).

Conclusions

Pneumothorax was seen in the active GPA, due to a variety of reasons, and gave rise to high fatality rate. Aggressive treatment of GPA can improve the prognosis. Older and lack of response for pleural drainage indicates poor prognosis.

CT Features of Vasculitides Based on the 2012 International Chapel Hill Consensus Conference Revised Classification

Vasculitis, characterized by inflammation of vessel walls, is comprised of heterogeneous clinicopathological entities, and thus poses a diagnostic challenge. The most widely used approach for classifying vasculitides is based on the International Chapel Hill Consensus Conference (CHCC) nomenclature system. Based on the recently revised CHCC 2012, we propose computed tomography (CT) features of vasculitides and a differential diagnosis based on location and morphological characteristics. Finally, vasculitis mimics should be differentiated, because erroneous application of immunosuppressive drugs on vasculitis mimics may be ineffective, even deteriorating. This article presents the utility of CT in the diagnosis and differential diagnosis of vasculitides.

Pulmonary Involvement in Antineutrophil Cytoplasmic Antibodies (ANCA)-associated Vasculitis: The Influence of ANCA Subtype

OBJECTIVE

To describe pulmonary involvement at time of diagnosis in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV), as defined by computed tomography (CT).

METHODS

Patients with thoracic CT performed on or after the onset of AAV (n = 140; 75 women; granulomatosis with polyangiitis, n = 79; microscopic polyangiitis MPA, n = 61) followed at a tertiary referral center vasculitis clinic were studied. Radiological patterns of pulmonary involvement were evaluated from the CT studies using a predefined protocol, and compared to proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA specificity.

RESULTS

Of the patients, 77% had an abnormal thoracic CT study. The most common abnormality was nodular disease (24%), of which the majority were peribronchial nodules, followed by bronchiectasis and pleural effusion (19%, each), pulmonary hemorrhage and lymph node enlargement (14%, each), emphysema (13%), and cavitating lesions (11%). Central airways disease and a nodular pattern of pulmonary involvement were more common in PR3-ANCA-positive patients (p < 0.05). Usual interstitial pneumonitis (UIP) and bronchiectasis were more prevalent in MPO-ANCA-positive patients (p < 0.05). Alveolar hemorrhage, pleural effusion, lymph node enlargement, and pulmonary venous congestion were more frequent in MPO-ANCA-positive patients.

CONCLUSION

Pulmonary involvement is frequent and among 140 patients with AAV who underwent a thoracic CT study, almost 80% have pulmonary abnormalities on thoracic CT. Central airway disease occurs exclusively among patients with PR3-ANCA while UIP were mainly seen in those with MPO-ANCA. These findings may have important implications for the investigation, management, and pathogenesis of AAV.

A 38-year-old man with progressive dyspnoea and ventricular tachycardia

CLINICAL INTRODUCTION

A previously healthy 38-year-old man presented with a 3-month history of progressive dyspnoea and ventricular tachycardia (VT). He suffered a viral illness 4 months earlier. There was no family history of cardiac disease or sudden cardiac death (SCD). ECG showed left bundle branch block (LBBB). Echocardiography revealed a dilated left ventricle with severely impaired systolic function. Coronary angiogram showed angiographically normal coronary arteries. He was diagnosed as having dilated cardiomyopathy and was referred for further assessment with cardiovascular magnetic resonance (CMR) (figure 1) and subsequently CT thorax.

QUESTION

What is the most likely diagnosis? Dilated cardiomyopathy secondary to HIVGranulomatosis with polyangiitis (GPA)SarcoidosisTuberculosisUnderlying malignancy with lung and cardiac metastases.

Pulmonary Vasculitis: Spectrum of Imaging Appearances

Pulmonary vasculitis is a relatively uncommon disorder, usually manifesting as part of systemic vasculitis. Imaging, specifically computed tomography, is often performed in the initial diagnostic workup. Although the findings in vasculitis can be nonspecific, they can provide important clues in the diagnosis, and guide the clinical team toward the right diagnosis. Radiologists must have knowledge of common and uncommon imaging findings in various vasculitides. Also, radiologists should be able to integrate the clinical presentation and laboratory test findings together with imaging features, so as to provide a meaningful differential diagnosis.

Pictorial essay of radiological features of benign intrathoracic masses

With increased exposure of patients to routine imaging, incidental benign intrathoracic masses are frequently recognized. Most have classical imaging features, which are pathognomonic for their benignity. The aim of this pictorial review is to educate the reader of radiological features of several types of intrathoracic masses. The masses are categorized based on their location/origin and are grouped into parenchymal, pleural, mediastinal, or bronchial. Thoracic wall masses that invade the thorax such as neurofibromas and lipomas are included as they may mimic intrathoracic masses. All examples are illustrated and include pulmonary hamartoma, pleural fibroma, sarcoidosis, bronchial carcinoid, and bronchoceles together with a variety of mediastinal cysts on plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI). Sometimes a multimodality approach would be needed to confirm the diagnosis in atypical cases. The study would include the incorporation of radionuclide studies and relevant discussion in a multidisciplinary setting.