From the Archives of the AFIP

[Smoking-related interstitial lung disease : Radiological findings, histopathological correlations, and clinical observations]

CLINICAL/METHODOLOGICAL ISSUE

Identifying smoking-related interstitial lung diseases (SRILD) in smokers is challenging, as clinical manifestations can be nonspecific, and there is a variety of SRILD entities that not only interconnect but can also overlap.

RADIOLOGICAL STANDARD PROCEDURES

In diagnosing SRILD, imaging techniques such as high-resolution computed tomography (HRCT) allow the identification of characteristic features, serving as crucial pieces of the puzzle for definitive differentiation.

PERFORMANCE

Studies have demonstrated that HRCT exhibits a sensitivity of approximately 80-90% in identifying SRILD, with a specificity around 70-80%. The conclusive diagnosis often requires a correlation between histopathological findings and clinical observations.

PRACTICAL RECOMMENDATIONS

Regular monitoring of smokers, especially when experiencing symptoms like shortness of breath and cough, coupled with a comprehensive diagnosis of SRILD, is crucial for accurate identification and individualized therapy.

Why making smoking cessation a priority for rare interstitial lung disease smokers?

This review aims to discuss the complex relationship between smoking and interstitial lung diseases (ILDs), emphasizing the significant morbidity and mortality associated with these conditions. While the etiology of ILDs remains multifactorial, cigarette smoking emerges as a prominent modifiable risk factor implicated in their pathogenesis and progression. This narrative review will provide insight into smoking-associated interstitial lung diseases and personalised approaches to smoking cessation. Epidemiological studies consistently link smoking to ILDs such as idiopathic pulmonary fibrosis (IPF), respiratory bronchiolitis-associated ILD (RB-ILD), and desquamative interstitial pneumonia (DIP), highlighting the urgent need for comprehensive tobacco cessation strategies. Despite the established benefits of smoking cessation, adherence to cessation programs remains challenging due to nicotine addiction, psychological factors, and social influences. The modest success rates of smoking cessation in ILD patients, emphasises the importance of tailored interventions and ongoing support is needed to overcome barriers and to improve outcomes of quitting smoking in this category of vulnerable patients.

Spectrum of Thoracic Imaging Findings in the Setting of Substance Abuse

ABSTRACT

Substance abuse continues to be prevalent nationwide and can lead to a myriad of chest pathologies. Imaging findings are vast and can include nodules, masses, ground-glass opacities, airspace disease, and cysts. Radiologists with awareness of these manifestations can assist in early identification of disease in situations where information is unable to be obtained from the patient. This review focuses on thoracic imaging findings associated with various forms of substance abuse, which are organized by portal of entry into the thorax: inhalation, ingestion, and injection.

Noninfectious Granulomatous Lung Disease: Radiological Findings and Differential Diagnosis

Granulomatous lung diseases (GLDs) are a heterogeneous group of pathological entities that can have different clinical presentations and outcomes. Granulomas are histologically defined as focal aggregations of activated macrophages, Langerhans cells, and lymphocytes, and may form in the lungs when the immune system cannot eliminate a foreign antigen and attempts to barricade it. The diagnosis includes clinical evaluation, laboratory testing, and radiological imaging, which especially consists of high-resolution computed tomography. bronchoalveolar lavage, transbronchial needle aspiration or cryobiopsy, positron emission tomography, while genetic evaluation can improve the diagnostic accuracy. Differential diagnosis is challenging due to the numerous different imaging appearances with which GLDs may manifest. Indeed, GLDs include both infectious and noninfectious, and necrotizing and non-necrotizing granulomatous diseases and the imaging appearance of some GLDs may mimic malignancy, leading to confirmatory biopsy. The purposes of our review are to report the different noninfectious granulomatous entities and to show their various imaging features to help radiologists recognize them properly and make an accurate differential diagnosis.

Pulmonary Hypertension in Chronic Lung Diseases: What Role Do Radiologists Play?

Pulmonary hypertension (PH) is a pathophysiological disorder, defined by a mean pulmonary arterial pressure (mPAP) > 20 mmHg at rest, as assessed by right heart catheterization (RHC). PH is not a specific disease, as it may be observed in multiple clinical conditions and may complicate a variety of thoracic diseases. Conditions associated with the risk of developing PH are categorized into five different groups, according to similar clinical presentations, pathological findings, hemodynamic characteristics, and treatment strategy. Most chronic lung diseases that may be complicated by PH belong to group 3 (interstitial lung diseases, chronic obstructive pulmonary disease, combined pulmonary fibrosis, and emphysema) and are associated with the lowest overall survival among all groups. However, some of the chronic pulmonary diseases may develop PH with unclear/multifactorial mechanisms and are included in group 5 PH (sarcoidosis, pulmonary Langerhans' cell histiocytosis, and neurofibromatosis type 1). This paper focuses on PH associated with chronic lung diseases, in which radiological imaging-particularly computed tomography (CT)-plays a crucial role in diagnosis and classification. Radiologists should become familiar with the hemodynamical, physiological, and radiological aspects of PH and chronic lung diseases in patients at risk of developing PH, whose prognosis and treatment depend on the underlying disease.

Cystic lung disease

The term cystic lung disease encompasses a heterogeneous group of entities characterised by round lung lesions that correspond to cysts with fine walls, which usually contain air. The differential diagnosis of these lesions can be challenging, requiring both clinical and radiological perspectives. Entities such as pulmonary emphysema and cystic bronchiectasis can simulate cystic disease. High-resolution computed tomography (HRCT) is the imaging technique of choice for the evaluation and diagnosis of cystic lung disease, because it confirms the presence of lung disease and establishes the correct diagnosis of the associated complications. In many cases, the diagnosis can be established based on the HRCT findings, thus making histologic confirmation unnecessary. For these reasons, radiologists need to be familiar with the different presentations of these entities. A wide variety of diseases are characterised by the presence of diffuse pulmonary cysts. Among these, the most common are lymphangioleiomyomatosis, which may or may not be associated with tuberous sclerosis, Langerhans cell histiocytosis, and lymphocytic interstitial pneumonia. Other, less common entities include Birt-Hogg-Dubé syndrome, amyloidosis, and light-chain deposit disease. This article describes the characteristics and presentations of some of these entities, emphasizing the details that can help differentiate among them.

High-Resolution Computed Tomography of Cystic Lung Disease

The cystic lung diseases (CLD) are characterized by the presence of multiple, thin-walled, air-filled spaces in the pulmonary parenchyma. Cyst formation may occur with congenital, autoimmune, inflammatory, infectious, or neoplastic processes. Recognition of cyst mimics such as emphysema and bronchiectasis is important to prevent diagnostic confusion and unnecessary evaluation. Chest CT can be diagnostic or may guide the workup based on cyst number, distribution, morphology, and associated lung, and extrapulmonary findings. Diffuse CLD (DCLDs) are often considered those presenting with 10 or more cysts. The more commonly encountered DCLDs include lymphangioleiomyomatosis, pulmonary Langerhans' cell histiocytosis, lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, and amyloidosis/light chain deposition disease.

Diffuse cystic lung diseases: Imaging spectrum and diagnostic approach using high-resolution computed tomography

The lung cyst is an air-containing lucent area surrounded by thin imperceptible walls. Other lucent lung lesions like centrilobular emphysema, cavity, cystic bronchiectasis, honeycomb cyst, and pneumatoceles are close mimics of a lung cyst on high-resolution computed tomography (HRCT). Various diseases with multiple lung cysts throughout both the lungs are classified as diffuse cystic lung diseases (DCLDs). HRCT is considered the imaging of choice for diagnosis of such diffuse cystic lung diseases. Common DCLDs like lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome (BHS), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), and desquamative interstitial pneumonia (DIP) can be confidently diagnosed on HRCT without further requirement of histopathological confirmation. The imaging also helps in differentiation of uncommon DCLDs and exclusion of the mimics. This review describes a simple algorithmic approach for DCLDs on HRCT based on scrutinizing the cyst's distribution, size, and shape, background parenchymal changes, and its correlation with clinical features and extrapulmonary imaging findings.

Raucherassoziierte interstitielle Lungenerkrankungen

Klinisches Problem

Raucherassoziierte interstitielle Lungenerkrankungen umfassen heterogene pulmonale Pathologien, deren korrekte Diagnostik prognostische und therapeutische Konsequenzen hat. In diesem Artikel werden die gängigsten raucherassoziierten interstitiellen Lungenerkrankungen beschrieben sowie eine strukturierte Herangehensweise präsentiert, welche den diagnostischen Arbeitsprozess erleichtern kann.

Empfehlungen für die Praxis

Die Computertomographie (CT) besitzt einen hohen Stellenwert in der Diagnose der raucherassoziierten interstitiellen Lungenerkrankungen und kann dazu beitragen, Lungenbiopsien zu verhindern. Um eine hohe diagnostische Genauigkeit zu erreichen, sollten standardisierte Untersuchungsprotokolle sowie eine strukturierte Herangehensweise in der Befundung zur Anwendung kommen. In den entzündlich dominierten Stadien der respiratorischen Bronchiolitis (RB), der respiratorischen Bronchiolitis mit interstitieller Lungenerkrankung (RB-ILD) sowie der desquamativen interstitiellen Pneumonie (DIP) haben die Beendigung des Rauchens sowie Steroide den größten therapeutischen Effekt. Bei fibrotischen Veränderungen (z. B. im Rahmen einer idiopathischen pulmonalen Fibrose [IPF]) können antifibrotische Therapien mit Pirfenidon und Nintedanib zum Einsatz kommen. Patienten mit dem Verdacht auf raucherassoziierte interstitielle Lungenerkrankung sollten in multidisziplinären Boards abgeklärt und behandelt werden.

Bronchoalveolar Lavage as a Diagnostic Tool in an Atypical Pulmonary Langerhans Cell Histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is an uncommon diffuse cystic lung disease that occurs almost exclusively in young adult smokers. High-resolution computed tomography of the chest allows a confident diagnosis of PLCH in typical presentation, when nodules, cavitating nodules, and cysts coexist and show a predominance for the upper and middle lung. Atypical presentations require histology for diagnosis. Histologic diagnosis rests on the demonstration of increased numbers of Langerhans cells and/or specific histological changes. PLCH is one of the few diseases in which bronchoalveolar lavage (BAL) has a high diagnostic value and can in some circumstances replace lung biopsy. We present a case of PLCH in an elderly non-smoker. Chest imaging revealed the presence of advanced interstitial lung disease with a fibrocystic pattern. BAL cellular analyses disclosed a macrophage pattern with CD1a phenotype that strongly supports the PLCH diagnosis, even in the setting of atypical clinical presentation and a lack of smoking exposure. PLCH is extremely rare in non-smokers and could represent a distinct phenotype.

The Octopus Sign—A New HRCT Sign in Pulmonary Langerhans Cell Histiocytosis

Background: Fibrosis in pulmonary Langerhans cell histiocytosis (PLCH) histologically comprises a central scar with septal strands and associated airspace enlargement that produce an octopus-like appearance. The purpose of this study was to identify the octopus sign on high-resolution computed tomography (HRCT) images to determine its frequency and distribution across stages of the disease. Methods: Fifty-seven patients with confirmed PLCH were included. Two experienced chest radiologists assessed disease stages as early, intermediate, or late, as well as the lung parenchyma for nodular, cystic, or fibrotic changes and for the presence of the octopus sign. Statistical analysis included Cohen’s kappa for interrater agreement and Fisher’s exact test for the frequency of the octopus sign. Results: Interobserver agreement was substantial for the octopus sign (kappa = 0.747). Significant differences in distribution of the octopus sign between stages 2 and 3 were found with more frequent octopus signs in stage 2 and fewer in stage 3. In addition, we only found the octopus sign in cases of nodular und cystic lung disease. Conclusions: The octopus sign in PLCH can be identified not only on histological images, but also on HRCT images. Its radiological presence seems to depend on the stage of PLCH.

Case 291: Amyloid-associated Cystic Lung Disease and Coexistent Mucosa-associated Lymphoid Tissue Lymphoma

History A 46-year-old woman with known mixed connective tissue disease with clinical features of scleroderma and polymyositis and who was not on specific medications was referred to our institution to assess for interstitial lung disease due to her predisposing condition. She was a nonsmoker, had no respiratory symptoms, and enjoyed good exercise tolerance. She did not have any cutaneous lesions or renal disease. There was no family history of pulmonary or systemic disease. Her routine blood test results revealed a white blood cell count of 4.6 × 10⁹/L (normal range, [4.4-10.1] × 10⁹/L), a hemoglobin level of 7.76 mmol/L (normal range, 7.26-9.18 mmol/L), a platelet count of 189 × 10⁹/L (normal range, [170-380] × 10⁹/L), a bilirubin level of 8 mmol/L (normal range, <19 mmol/L), and a creatinine level of 63 mmol/L (normal range, 45-82 mmol/L), all within normal limits. Lung function tests at presentation yielded normal results, with a diffusing capacity for carbon monoxide of 95% and a forced vital capacity of 2.29 (98% predicted value). However, this patient had an elevated serum globulin level of 47 g/L (normal range, 26-32 g/L) and an erythrocyte sedimentation rate of 36 mm/h (normal range, 0-20 mm/h), while C-reactive protein level was normal at less than 0.35 mg/dL. She was seropositive for antinuclear (titer >1/720), anti-Ro, anti-La, and anti-extractable nuclear antigen antibodies. Chest radiography and CT were performed at presentation and 14-year follow-up. PET/CT was performed at 7- and 13-year follow-up. Throughout this 14-year follow-up period, she remained completely free of respiratory symptoms and continued to go for a brisk walk every day. At 14-year follow-up, there was no substantial change in serum laboratory values, but a lung function test revealed her diffusing capacity for carbon monoxide had decreased to 52%, while her forced vital capacity remained good at 95%; these findings were suggestive of interval development of restrictive lung function.

Imaging features of neonatal systemic juvenile xanthogranuloma: a case report and review of the literature

Juvenile xanthogranuloma (JXG) is the most common non-Langerhans cell histiocytic disorder in children. This report describes the case of a 28-day-old boy that presented with multiple subcutaneous nodular lesions on the trunk and extremities, and multiple red nodular lesions on the scrotum. Magnetic resonance imaging (MRI) of the brain showed a well-demarcated extra-axial dura-based mass that appeared isointense or slightly hyperintense on T1-weighted images, hypointense on T2-weighted images and had intense enhancement on gadolinium-enhanced T1-weighted images. Computed tomography (CT) or MRI scans of the chest and abdomen revealed multiple scattered nodular or patchy lesions of varying sizes in the lungs, liver and left kidney. Histological analysis of a subcutaneous mass suggested JXG. The patient was diagnosed with neonatal systemic JXG with involvement of the central nervous system, lungs, liver, kidneys, subcutaneous soft tissue and skin. CT and MRI after 3 months of treatment with methylprednisolone sodium succinate demonstrated that the lesions were obviously diminished. This report discusses the imaging findings in this current case of multi-organ JXG and reviews the imaging literature on this condition to improve awareness of the lesions in order to help radiologists establish an accurate differential diagnosis when confronted with similar cases.

Early and Atypical Radiologic Presentations of Pulmonary Langerhans Cell Histiocytosis: A Report of Two Cases

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, multi-systemic disease primarily affecting young male adults with a history of smoking. The two patients with PLCH in our report showed relatively early and atypical radiologic presentations at initial evaluation. On chest CT, PLCH presents variable radiologic features depending on the evolutional stage of the disease. Atypical CT features of PLCH may render precise radiologic diagnosis difficult and usually require lung biopsy for a confirmation of the diagnosis. Our case review is aimed at raising the awareness of radiologists on the atypical CT features of PLCH, to help make accurate radiologic diagnosis and prevent unnecessary and invasive diagnostic procedures.

CT findings of pulmonary cysts

Pulmonary cysts are thin-walled radiolucent lesions that may appear in a variety of uncommon disorders known as diffuse cystic lung diseases (DCLD) that essentially includes lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), Pneumocystis jiroveci pneumonia (PJP), and Birt-Hogg-Dubé syndrome (BHDS). Moreover, they have been reported in several cases of coronavirus disease 2019 (COVID-19). The purpose of this review is to provide a practical approach for evaluating lung cysts when encountered on CT. We describe the imaging findings of DLCD emphasising their differences in terms of shape and distribution of the cysts, as well as their association with other findings such as nodules or ground-glass opacities, which may help in making a confident diagnosis. We also discuss the link between pulmonary cysts and COVID-19.

Adult form of Langerhans cell histiocytosis with pulmonary and hepatic involvement mimicking malignancy in a patient with chronic hepatitis C infection

Langerhans cell histiocytosis (LCH) is a myeloid neoplasm with inflammatory properties. There are few published reports of adult LCH with liver involvement, which is still poorly understood, but shows high morbidity and mortality. We report a case of a 37-year-old woman suffering from hepatitis C showing a LCH affecting the lung as well as the liver. Consistent with histology, we found an early stage of a proliferative/granulomatous phase of hepatobiliary LCH, whereas pulmonary findings showed a nodular stage of adult pulmonary LCH. Although hepatocellular carcinoma is a common malignancy in patients suffering from hepatitis C, it is crucial to keep in mind differential diagnosis for newly appearing liver lesions.

A Stepwise Diagnostic Approach to Cystic Lung Diseases for Radiologists

Lung cysts are commonly seen on computed tomography (CT), and cystic lung diseases show a wide disease spectrum. Thus, correct diagnosis of cystic lung diseases is a challenge for radiologists. As the first diagnostic step, cysts should be distinguished from cavities, bullae, pneumatocele, emphysema, honeycombing, and cystic bronchiectasis. Second, cysts can be categorized as single/localized versus multiple/diffuse. Solitary/localized cysts include incidental cysts and congenital cystic diseases. Multiple/diffuse cysts can be further categorized according to the presence or absence of associated radiologic findings. Multiple/diffuse cysts without associated findings include lymphangioleiomyomatosis and Birt-Hogg-Dubé syndrome. Multiple/diffuse cysts may be associated with ground-glass opacity or small nodules. Multiple/diffuse cysts with nodules include Langerhans cell histiocytosis, cystic metastasis, and amyloidosis. Multiple/diffuse cysts with ground-glass opacity include pneumocystis pneumonia, desquamative interstitial pneumonia, and lymphocytic interstitial pneumonia. This stepwise radiologic diagnostic approach can be helpful in reaching a correct diagnosis for various cystic lung diseases.

Noninfectious Granulomatous Diseases of the Chest

Granulomas are pathologically defined as focal aggregations of activated macrophages, Langerhans cells, and lymphocytes. Granulomas form in the lungs when the immune system barricades the substances it perceives as foreign but is unable to remove. Granulomas manifest with numerous imaging appearances in thoracic radiology, and their presence is a nonspecific finding. Granulomatous lung diseases comprise multiple entities with variable clinical manifestations and outcomes. Their imaging findings are rarely specific and can mimic malignancies, often triggering an extensive diagnostic workup. Radiologists must be familiar with the clinical manifestations and imaging findings of these entities to generate appropriate differential diagnoses. This review describes the imaging manifestations of various noninfectious, necrotizing, and nonnecrotizing granulomatous diseases that primarily affect the thorax. ©RSNA, 2020.

Cystic Interstitial Lung Diseases: A Pictorial Review and a Practical Guide for the Radiologist

A cyst is a round circumscribed area of low attenuation, surrounded by epithelial or fibrous wall. Cysts can frequently occur on chest computed tomography (CT) and high-resolution computed tomography (HRCT); multiple parenchymal cysts of the lungs are the most typical feature of cystic lung interstitial diseases, characterizing a wide spectrum of diseases—ranging from isolated lung disorders up to diffuse pulmonary diseases. The aim of this review is to analyze scientific literature about cystic lung interstitial diseases and to provide a practical guide for radiologists, focusing on the main morphological features of pulmonary cysts: size, shape, borders, wall, location, and distribution. These features are shown on free-hand drawings and related to HRCT images, in order to help radiologists pursue the correct differential diagnosis between similar conditions.

Left destroyed lung caused by a pen cap in the left lower lobe bronchus "swallowed" 25 years ago

A delayed diagnosis of tracheobronchial foreign body aspiration (FBA) may result in severe respiratory complications such as pneumonia, bronchiectasis, and atelectasis. Here, we present a rare case of a left lung destruction caused by a pen cap that remained in the left lower lobe bronchus for 25 years and was previously misdiagnosed as cavitary tuberculosis. The foreign body was not detected in bronchoscopic examination prior to surgery due to severe stenosis of the left main bronchus. The foreign body was found incidentally while the patient was undergoing left pneumonectomy. To the best of our knowledge, this the second longest delay to diagnosis of FBA reported. This case also exemplifies the grave consequences of misdiagnosis of FBA.

Familial pneumothoraces - Birt-Hogg-Dubé syndrome. Differentiation with other cystic lung diseases

Birt-Hogg-Dubé syndrome (BHDS) is a rare, genetic, autosomal dominant disease caused by mutation in a folliculin gene. This syndrome is characterised by three main symptoms: benign lesions originating from hair follicles, variously shaped cysts in the lungs, and various types of benign and malignant kidney neoplasms. In our article we are going to present cases of two sisters with BHDS. In the case of the first sister skin lesions were accompanied by lung abnormalities. The second sister, however, presented with recurrent pneumothoraces associated with variously shaped lung cysts located mainly below the tracheal carina. In both instance diagnosis was confirmed by genetic test.

Role of thoracic imaging in the management of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare diffuse lung cystic disease (DLCD) that occurs sporadically or in association with Tuberous Sclerosis Complex (TSC). The diagnostic pathway is tracked on the identification of the disease hallmarks on chest High-Resolution Computed Tomography (HRCT). Aim of this review is to discuss the thoracic HRCT pathognomonic features, essential to rule out other DLCD. It also examines the new evidences emerging from Computed Tomography (CT) quantitative studies that, by demonstrating a specific cysts distribution and a pathological aspect of the parenchyma near the cysts, could improve our understanding of this rare disorder and supply pulmonologists with a new tool for a more appropriate long-term management. Finally, the contribution of other image techniques as low dose chest CT, Magnetic Resonance Imaging (MRI) and Ultrasound (US) is discussed.

Birt-Hogg-Dubé syndrome: characteristic CT findings differentiating it from other diffuse cystic lung diseases

Birt-Hogg-Dubé (BHD) syndrome is an uncommon, autosomal dominant, multiorgan systemic disorder manifesting as cutaneous fibrofolliculomas, lung cysts with or without spontaneous pneumothorax, and renal tumors. Spontaneous pneumothorax and lung cysts on chest computed tomography (CT) should lead to the inclusion of BHD syndrome in the differential diagnosis, because these findings may develop earlier than other clinical manifestations. Here, we review and describe the characteristic findings of BHD syndrome. The number, shape, size, and distribution of the lung cysts can help to differentiate BHD syndrome from other diffuse cystic lung diseases. Knowledge of the chest CT findings of BHD syndrome may lead to a correct diagnosis and the initiation of an appropriate work-up in order to prevent pneumothorax and for the early detection of renal tumors.

Current Concepts in Pathogenesis, Diagnosis, and Management of Smoking-Related Interstitial Lung Diseases

Tobacco exposure results in various changes to the airways and lung parenchyma. Although emphysema represents the more common injury pattern, in some individuals, cigarette smoke injures alveolar epithelial cells and other lung cells, resulting in diffuse infiltrates and parenchymal fibrosis. Smoking can trigger interstitial injury patterns mediated via recruitment and inappropriate persistence of myeloid and other immune cells, including eosinophils. As our understanding of the role of cigarette smoke constituents in triggering lung injury continues to evolve, so does our recognition of the spectrum of smoking-related interstitial lung changes. Although respiratory bronchiolitis-interstitial lung disease, desquamative interstitial pneumonia, pulmonary Langerhans cell histiocytosis, and acute eosinophilic pneumonia have a well-established association with tobacco use, its role and impact on idiopathic pulmonary fibrosis, combined pulmonary fibrosis and emphysema, and connective tissue disease-related interstitial lung diseases is still ambiguous. Smoking-related interstitial fibrosis is a relatively newly appreciated entity with distinct histopathologic features but with unclear clinical ramifications. Increased implementation of lung cancer screening programs and utilization of CT scans in thoracic imaging have also resulted in increased identification of "incidental" or "subclinical" interstitial lung changes in smokers, the ensuing impact of which remains to be studied.

Langerhans cell histiocytosis: Skin diseases and visceral lesions

Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disorder that belongs to class I histiocytoses and is characterized by infiltration of one or many organs by Langerhans cells to form granulomas. The literature analysis could identify a lot of etiological, pathogenetic, and trigger factors and mechanisms for LCH development, which determine the diversity of the clinical picture and course of the disease. The clinical manifestations of LCH are very variable and depend on the severity of lesions and the age of patients. In addition to skin lesions, there is involvement of one or more visceral organs. Difficulties in diagnosing the disease lead to statistical variations of LCH in different countries of the world and require more attention by physicians of all specialties.

Interstitial Lung Diseases

The term interstitial lung diseases (ILD) comprises a diverse group of diseases that lead to inflammation and fibrosis of the alveoli, distal airways, and septal interstitium of the lungs. The ILD consist of disorders of known cause (e.g., collagen vascular diseases, drug-related diseases) as well as disorders of unknown etiology. The latter include idiopathic interstitial pneumonias (IIPs), and a group of miscellaneous, rare, but nonetheless interesting, diseases. In patients with ILD, MDCT enriches the diagnostic armamentarium by allowing volumetric high-resolution scanning, i.e., continuous data acquisition with thin collimation and a high spatial frequency reconstruction algorithm. CT is a key method in the identification and management of patients with ILD. It not only improves the detection and characterization of parenchymal abnormalities, but also increases the accuracy of diagnosis. The spectrum of morphologic characteristics that are indicative of interstitial lung disease is relatively limited and includes the linear and reticular pattern, the nodular pattern, the increased attenuation pattern (such as ground-glass opacities and consolidation), and the low attenuation pattern (such as emphysema and cystic lung diseases). In the correct clinical context, some patterns or combination of patterns, together with the anatomic distribution of the abnormality, i.e., from the lung apex to the base, or peripheral subpleural versus central bronchovascular, can lead the interpreter to a specific diagnosis. However, due to an overlap of the CT morphology between the various entities, the final diagnosis of many ILD requires close cooperation between clinicians and radiologists and complementary lung biopsy is recommended in many cases.

Cardiothoracic manifestations of primary histiocytoses

The objectives of this article were: (1) to review common and rare manifestations of systemic and pulmonary Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease and juvenile xanthogranuloma; (2) to provide the reader with important pathologic, epidemiologic and clinical features of these diseases. The histiocytoses are a diverse group of diseases which typically manifest with multiorgan involvement. Understanding the pathologic, epidemiologic and clinical features of these entities can help the radiologist suggest an accurate diagnosis of histiocytosis when typical imaging features are encountered.

Clinical-Radiologic-Pathologic Correlation of Smoking-Related Diffuse Parenchymal Lung Disease

The direct toxicity of cigarette smoke and the body's subsequent response to this lung injury leads to a wide array of pathologic manifestations and disease states that lead to both reversible and irreversible injury to the large airways, small airways, alveolar walls, and alveolar spaces. These include emphysema, bronchitis, bronchiolitis, acute eosinophilic pneumonia, pulmonary Langerhans cell histiocytosis, respiratory bronchiolitis, desquamative interstitial pneumonia, and pulmonary fibrosis. Although these various forms of injury have different pathologic and imaging manifestations, they are all part of the spectrum of smoking-related diffuse parenchymal lung disease.

A confusing case report of pulmonary langerhans cell histiocytosis and literature review

Pulmonary Langerhans Cell Histiocytosis (PLCH) is a rare disease. From the insidious onset and nonspecific manifestations, it is difficult to diagnose PLCH. To help improve the diagnosis and therapy options of adult PLCH, we present this case report and literature review about a confusing case of PLCH. In this report, we present a 37-year-old male PLCH case that was negative for CD1a and S100 expression. Smoking cessation and use of prescribed Spiriva appeared to improve the patient’s symptoms. To the best of our knowledge, this is the first reported case of PLCH in which improved symptoms were seen with the use of Spiriva alone.The mechanism is not clear, but potentially has some relationship with dilating the airway, decreasing the mucous hypersecretion and promoting anti-inflammatory pathways. From this patient’s case, we may be able to find more cases to then find other first line therapies for PLCH patients.

Pulmonary Langerhans cell histiocytosis: analysis of 14 patients and literature review

BACKGROUND

Pulmonary Langerhans cell histiocytosis (PLCH) is an orphan disease in respiratory medicine, which most affects adult smokers. The purpose of this article was to discuss the clinical features, especially the radiologic features of PLCH patients during their hospitalization through a retrospective analysis on clinical data. Furthermore, the current literature was also reviewed.

METHODS

Between December 2008 and June 2012, 14 patients with PLCH were assessed at Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. Among these patients, seven patients were diagnosed through tissue biopsy from the lung and one patient from enlarged cervical lymph nodes; the rest of six patients were diagnosed based on the clinical-radiological data. The data consisting of demographics, clinical presentation, smoking habits, pulmonary function tests (PFTs) and radiographic image from the medical records was analyzed retrospectively.

RESULTS

The average age of patients (11 males and 3 females) was 42.79 (±13.71) years old. All male patients and one female patient had a long smoking history. The common manifestations were cough and exertional dyspnea. Spontaneous pneumothorax was found in three patients. Varieties of pulmonary shadows such as nodular, cystic, patch-like and cord-like were revealed by chest computed tomography (CT) examination. Large Langerhans cells (LCs) were discovered in biopsy tissue by immunohistochemical stains.

CONCLUSIONS

PLCH is still an orphan disease and maybe related to smoking. Clinical symptoms such as cough and exertional dyspnea are non-specific. We shall pay attention to recurrent pneumothorax as clinically it is associated with PLCH. The characteristic radiological manifestation is cystic or nodular shadow in the lungs, which plays crucial roles in diagnosing PLCH.

Interstitial lung disease related to smoking: imaging considerations

PURPOSE OF REVIEW

To discuss the imaging of interstitial lung disease believed to be caused by smoking.

RECENT FINDINGS

It is increasingly clear that smoking is associated with a variety of patterns of interstitial lung disease. The radiologic features of interstitial lung disease caused by smoking cigarettes are variable and may be nonspecific.

SUMMARY

It is now accepted that cigarette smoking can cause lung diseases other than lung cancer, chronic bronchitis and emphysema. Indeed, the hypothesis that tobacco smoke can cause interstitial lung disease - and, specifically, pulmonary fibrosis - dates back to the 1960s. The list of interstitial lung disease, in which smoking is believed to have an etiologic role, includes Langerhans' cell histiocytosis, respiratory bronchiolitis/respiratory bronchiolitis-interstitial lung disease and desquamative interstitial pneumonia. More recently, there is emerging evidence which suggests that smoking may be associated with other patterns of pulmonary fibrosis (e.g. nonspecific interstitial pneumonia and smoking-related interstitial fibrosis). In the present review we discuss the imaging of the interstitial lung disease known to be caused by smoking; the typical appearances and some of the diagnostic difficulties are discussed.

Radiographic and Pathologic Manifestations of Uncommon and Rare Pulmonary Lesions

Pulmonary opacities/nodules are common findings on computed tomography examinations, which may represent an underlying infections or malignancy. However, not every pulmonary nodule or opacity represents malignancy or infection. We present a pictorial essay illustrating common as well as obscure noninfectious, nonmalignant pulmonary lesions. Lesions discussed include organizing pneumonia, Langerhans cell histiocytosis, pulmonary amyloidosis, hyalinizing granuloma, tumourlet (benign localized neuroendocrine cell proliferations), atypical alveolar hyperplasia, inflammatory myofibroblastic tumour, papillary alveolar adenoma, plasma cell granuloma, juvenile xanthogranuloma, and sclerosing hemangiomas. We discuss the clinical presentation, prevalence, radiographic clues, pathology, and diagnostic pitfalls of these rare lesions.

Multiple cystic lung disease

Multiple cystic lung disease represents a diverse group of uncommon disorders that can present a diagnostic challenge due to the increasing number of diseases associated with this presentation. High-resolution computed tomography of the chest helps to define the morphological aspects and distribution of lung cysts, as well as associated findings. The combination of appearance upon imaging and clinical features, together with extrapulmonary manifestations, when present, permits confident and accurate diagnosis of the majority of these diseases without recourse to open-lung biopsy. The main diseases in this group that are discussed in this review are lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis and folliculin gene-associated syndrome (Birt–Hogg–Dubé); other rare causes of cystic lung disease, including cystic metastasis of sarcoma, are also discussed. Disease progression is unpredictable, and understanding of the complications of cystic lung disease and their appearance during evolution of the disease are essential for management. Correlation of disease evolution and clinical context with chest imaging findings provides important clues for defining the underlying nature of cystic lung disease, and guides diagnostic evaluation and management.

Pulmonary cysts identified on chest CT: are they part of aging change or of clinical significance?

OBJECTIVE

To investigate the prevalence and natural course of pulmonary cysts in a population-based cohort and to describe the CT image characteristics in association with participant demographics and pulmonary functions.

MATERIALS AND METHODS

Chest CT scans of 2633 participants (mean age 59.2 years; 50% female) of the Framingham Heart Study (FHS) were visually evaluated for the presence of pulmonary cysts and their image characteristics. These findings were correlated with participant demographics and results of pulmonary function tests as well as the presence of emphysema independently detected on CT. The interval change was investigated by comparison with previous CT scans (median interval 6.1 years).

RESULTS

Pulmonary cysts were seen in 7.6% (95% CI 6.6% to 8.7%; 200/2633). They were not observed in participants younger than 40 years old, and the prevalence increased with age. Multiple cysts (at least five) were seen in 0.9% of all participants. Participants with pulmonary cysts showed significantly lower body mass index (BMI) (p<0.001). Pulmonary cysts were most likely to appear solitary in the peripheral area of the lower lobes and remain unchanged or slightly increase in size over time. Pulmonary cysts showed no significant influence on pulmonary functions (p=0.07-0.6) except for diffusing capacity of the lung for carbon monoxide (DLCO) (p=0.03) and no association with cigarette smoking (p=0.1-0.9) or emphysema (p=0.7).

CONCLUSIONS

Pulmonary cysts identified on chest CT may be a part of the aging changes of the lungs, occurring in asymptomatic individuals older than 40 years, and are associated with decreased BMI and DLCO. Multiple pulmonary cysts may need to be evaluated for the possibility of cystic lung diseases.

Unusual cystic hamartomatous lung lesion with clinical manifestation of subpleural bullae in a woman of reproductive age: A case report

Pulmonary hamartoma is a common benign lung disorder, and most cases show solid nodules. Here, we documented the clinicopathological features of a growing, bulla-like, multilocular hamartomatous lung lesion in a woman of reproductive age. To the best of our knowledge, this disorder has not been reported in the literature to date. An asymptomatic 29-year-old Japanese woman with no significant past medical history was referred to our institution for surgical treatment of a bullous lesion in the right upper lobe because the pulmonary lesion had enlarged to multilocular cysts, including a giant bulla, within 1 year, leading to compression of the right lung. The bullous lesion, which was projected from the apex of the lung via a narrow stalk, showed nonemphysematous, multiloculated tissue. The wall mimicked a bronchiolar structure with ciliated, nonatypical epithelium and layers of nonatypical spindle cells that were positive for smooth muscle markers and sex steroid hormone receptors. No cartilage was included in the lesion. We believe that this may be a novel form of hamartoma. This disorder may be included in a differential diagnosis of subpleural bullous diseases in women of reproductive age.

A different cause for respiratory disorder in children: cases with pulmonary Langerhans cell histiocytosis

BACKGROUND AND AIMS

In children, complaints of a respiratory disorder are very frequent. Etiology of respiratory illness is a broad spectrum that varies from a simple viral infection to a malignant disorder. Pulmonary Langerhans cell histiocytosis (PLCH) is one of these entities and it is truly rare in children. The aim of this study is to evaluate our patients with PLCH.

METHODS

Patients who had been diagnosed with PLCH were retrospectively evaluated. Features of medical history, onset of the complaints, date of the diagnosis, chest X-Ray and computed tomography (CT) findings, histopathology and other laboratory investigations were considered.

RESULTS

There were four cases with PLCH. All of them were male, ages were between 5 months and 16 years. In three cases, major complaints were chronic respiratory problems whereas in one of them there was acute respiratory distress beginning with cough and leading to pneumothorax. In all of the cases, multisystemic involvement was prominent. The diagnosis was proven by histopathology in all of the cases. In two children with smaller age, skin involvement was detected. Time from complaint to diagnosis was minimum 3 months and maximum 3 years.

CONCLUSION

PLCH is a rare disorder in children. Pulmonary involvement is generally a component of systemic involvement but in many cases it might have been detected with early respiratory complaints. So, children with chronic respiratory problems should be carefully evaluated and should be followed up for rare entities like PLCH.

Cystic and nodular lung disease

Diffuse cystic and nodular lung diseases have characteristic imaging findings. The most common causes of cystic lung disease are lymphangioleiomyomatosis and Langerhans cell histiocytosis. Other less common cystic lung diseases include Birt-Hogg-Dube syndrome, lymphocytic interstitial pneumonitis, and light chain deposition disease. Computed tomography is used to differentiate cystic lung disease from emphysema, honeycombing, cavities, and bronchiectasis, which mimic cystic lung disease. Diffuse nodular lung disease are categorized as centrilobular, perilymphatic, and random types. In diffuse nodular lung disease, a specific diagnosis is achieved through a combination of history, physical examination, and imaging findings.

Rare interstitial lung disease: Pulmonary Langerhans Cell Histiocytosis in a young non smoking Indian female

Adult Pulmonary Langerhans Cell Histiocytosis (PLCH) is a rare interstitial lung disease which occurs almost exclusively in smokers. A marked male predominance was initially reported, but recent studies show both men and women are equally affected due to the increasing smoking habits in women. The natural history is variable with 25% of patients having asymptomatic disease while 10-20% progress rapidly to respiratory insufficiency and death. The diagnosis is not easily recognized by clinicians or pathologists. Awareness of the clinical presentation and classical HRCT findings helps in early diagnosis and management of this disease. We report a rare case of severe PLCH in a young non smoking female with a short history who progressed rapidly to respiratory failure and died.