Lymphoid interstitial pneumonia: a narrative review

Pulmonary Manifestations of Sjögren's Disease

Sjögren's disease (SjD) is a chronic, progressive autoimmune condition of exocrine and extraglandular tissues. It can present with isolated disease characterized by lymphocytic infiltration of salivary or lacrimal glands, but in approximately one-third of the patients, lymphocytic infiltration extends beyond exocrine glands to involve extraglandular organs such as the lungs. Pulmonary complications have been reported to occur between 9 and 27% of patients with SjD across studies. Respiratory manifestations occur on a spectrum of severity and include airways disease, interstitial lung disease, cystic lung disease, and lymphoma. Lung involvement can greatly affect patients' quality of life, has a major impact on the overall prognosis, and frequently leads to alteration in the treatment plans, highlighting the importance of maintaining a high index of clinical suspicion and taking appropriate steps to facilitate early recognition and intervention.

Connective tissue disease-associated lung disease in children

Connective tissue diseases are a heterogeneous group of autoimmune diseases that can affect a variety of organ systems. Lung parenchymal involvement is an important contributor to morbidity and mortality in children with connective tissue disease. Connective tissue disease-associated lung disease in children often manifests as one of several radiologic-pathologic patterns of disease, with certain patterns having a propensity to occur in association with certain connective tissue diseases. In this article, key clinical, histopathologic, and computed tomography (CT) features of typical patterns of connective tissue disease-associated lung disease in children are reviewed, with an emphasis on radiologic-pathologic correlation, to improve recognition of these patterns of lung disease at CT and to empower the pediatric radiologist to more fully contribute to the care of pediatric patients with these conditions.

An unusual case of persistent consolidation: Idiopathic lymphoid interstitial pneumonia

Lymphocytic interstitial pneumonia (LIP) is a rare but largely benign interstitial lung disease, most frequently associated with HIV and autoimmune conditions. It is infrequently found to be an idiopathic condition. Diagnosis is complex and can require numerous invasive tests as evidenced in the case presented. The diagnosis is made from a combination of clinical, radiological, and histological features but the unusual radiological and clinical features meant diagnosis in our case required surgical biopsy. There is minimal evidence around best treatment although largely involves targeting the underlying cause. There is a small risk of transformation to lymphoma and fibrosis. Immunosuppression with steroids is the most common therapeutic strategy however in our case the radiographic changes spontaneously resolved. We present a case of an immunocompetent male presenting with significant radiological and histopathological findings of LIP, without significant symptomatology, that spontaneously resolved without intervention suggesting a monitoring approach may be a valid management strategy.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

Diagnosis of cystic lung diseases: a position statement from the UK Cystic Lung Disease Rare Disease Collaborative Network

BACKGROUND

Rare cystic lung diseases are increasingly recognised due the wider application of CT scanning making cystic lung disease management a growing part of respiratory care. Cystic lung diseases tend to have extrapulmonary features that can both be diagnostic but also require surveillance and treatment in their own right. As some of these diseases now have specific treatments, making a precise diagnosis is crucial. While Langerhans cell histiocytosis, Birt-Hogg-Dubé syndrome, lymphoid interstitial pneumonia and lymphangioleiomyomatosis are becoming relatively well-known diseases to respiratory physicians, a targeted and thorough workup improves diagnostic accuracy and may suggest other ultrarare diseases such as light chain deposition disease, cystic pulmonary amyloidosis, low-grade metastatic neoplasms or infections. In many cases, diagnostic information is overlooked leaving uncertainty over the disease course and treatments.

AIMS

This position statement from the Rare Disease Collaborative Network for cystic lung diseases will review how clinical, radiological and physiological features can be used to differentiate between these diseases.

NARRATIVE

We highlight that in many cases a multidisciplinary diagnosis can be made without the need for lung biopsy and discuss where tissue sampling is necessary when non-invasive methods leave diagnostic doubt. We suggest an initial workup focusing on points in the history which identify key disease features, underlying systemic and familial diseases and a clinical examination to search for connective tissue disease and features of genetic causes of lung cysts. All patients should have a CT of the thorax and abdomen to characterise the pattern and burden of lung cysts and extrapulmonary features and also spirometry, gas transfer and a 6 min walk test. Discussion with a rare cystic lung disease centre is suggested before a surgical biopsy is undertaken.

CONCLUSIONS

We suggest that this focused workup should be performed in all people with multiple lung cysts and would streamline referral pathways, help guide early treatment, management decisions, improve patient experience and reduce overall care costs. It could also potentially catalyse a national research database to describe these less well-understood and unidentified diseases, categorise disease phenotypes and outcomes, potentially leading to better prognostic data and generating a stronger platform to understand specific disease biology.

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.

Lymphocytic interstitial non-HIV-related pneumonia in pediatrics: a case report

Lymphocytic interstitial pneumonia (LIP) in pediatric patients without human immunodeficiency virus (HIV) infection remains a poorly characterized and enigmatic disease. Immunological dysregulation, mutations in the COPA gene, and increased morbidity and mortality have been reported in these patients. We present a case of LIP in a pediatric patient without HIV infection. This patient was infected with human T-lymphotropic virus type 1 (HTLV-1) and required right lower lobectomy with pathological findings compatible with lymphocytic interstitial pneumonia. In addition, bronchiectasis, dermatological involvement, and malnutrition were documented. However, no autoimmune disease, polymyositis, myelopathy, or opportunistic infections were found. There were no abnormalities in cellular and humoral immunity. A genetic study identified heterozygous mutations in the SCNN1B, FCHO1, and IL7R genes using single exome sequencing of coding and splicing regions. Although these heterozygous variants are not reported to be aetiological for LIP or diagnostic for the patient's congenital immunodeficiency, we believe they are associated with the severe lung damage seen in the patient's case.

STK4 deficiency and epidermodysplasia verruciformis-like lesions: A case report

Serine/threonine kinase 4 deficiency (STK4 or MST1, OMIM:614868) is an autosomal recessive (AR) combined immunodeficiency that can present with skin lesions such as epidermodysplasia verruciformis-like lesions (EVLL). Herein, we describe a 17-year-old male patient born from consanguineous parents presenting with recurrent respiratory infections, verruciform plaques, poikiloderma, chronic benign lymphoproliferation, and Sjögren syndrome with suspected interstitial lymphocytic pneumonia.

Lymphoid interstitial pneumonia in a patient with systemic lupus erythematosus: Case report and literature review

Lymphoid interstitial pneumonia (LIP) is a rare form of interstitial pulmonary disease, which has been described in association with a wide range of autoimmune disorders. Although the association of this entity with Sjogren's syndrome is well known, only a few cases are reported in relation to systemic lupus erythematosus (SLE). The aim of this paper is to review the cases reported in literature to date, as well as to describe the characteristics of these patients including the new case presented herein. We will be focusing on the case of a 36-year-old female patient diagnosed with SLE on hydroxychloroquine treatment who develops pleuritic chest pain and progressive dyspnea after 3 years of follow-up. The chest CT scan showed pleural thickening and both multiple and bilateral micronodules. A lung biopsy was also performed, revealing an infiltration of lymphocytes, plasma cells, and histiocytes in the alveolar septa suggestive of LIP. After conducting a review of the literature, we identified seven other cases describing SLE in association with LIP. The majority of them were young women, and LIP tends to appear early in the course of the disease, even as a form of initial presentation in some cases. Symptoms included cough, dyspnea, and pleuritic pain, with the exception of one case which was asymptomatic. It is noteworthy that half of the patients were positive for anti-SSA/anti-SSB autoantibodies, and some of them also met criteria for Sjogren's syndrome. Treatment with steroids and other immunosuppressive agents improved symptoms in all of them.

Coexistent Sjogren's syndrome and Birt-Hogg-Dube´ syndrome: a case report

We report a rare case of Sjogren's syndrome complicated with Birt-Hogg-Dubé syndrome (BHDS) not previously mentioned in the literature. Further, there is insufficient evidence linking the two diseases. Here, we review existing diagnostic algorithms for diagnosing diffuse cystic lung disease and provide new insights. The patient initially complained of thirst and dry eyes for ten years, and gradually developed shortness of breath. After admission, physical examination showed five missing teeth, decreased respiratory sounds in both lower lungs, and Velcro rales. Computed tomography showed multiple thin-walled cystic lesions in both lungs. Initial xerophthalmia and labial gland biopsy seemed to reveal a pulmonary cystic change associated with Sjogren's syndrome. Before discharge, a rash suspected to indicate a fibrofollicular tumor in the neck was observed, and then FLCN variant has been found. The challenges how to clarify the diagnosis of DCLD causes are discussed.

Lymphocytic interstitial pneumonia presenting with a ground glass nodule: A case report and literature review

RATIONALE

Lymphocytic interstitial pneumonia (LIP) is a rare benign lymphoproliferative disorder, often associated with autoimmune diseases. Most LIPs present with multiple bronchial cysts and diffuse interstitial infiltration. It is histologically characterized by widespread diffuse lymphocytic infiltration of the pulmonary interstitium, and the enlargement and widening of the alveolar septum.

PATIENT CONCERNS

A 49-year-old woman was admitted to hospital for finding pulmonary nodules for more than 2 months. 3D imaging chest computed tomography (CT) examination of both lungs showed that there was a middle lobe of the right lung with a size of about 1.5 cm × 1.1 cm ground-glass nodules.

DIAGNOSES

A single operating port thoracoscopic wedge resection biopsy of a right middle lung nodule was performed. The pathology showed diffuse lymphocytic infiltration with varying numbers of small lymphocytes, plasma cells, macrophages and histiocytes infiltrating the alveolar septa, widened and enlarged alveolar septa, and scattered lymphoid follicles. Immunohistochemically, CD20 positive in follicular area, CD3 positive in interfollicular area. LIP was considered.

INTERVENTIONS

The patient was regularly followed without any specific treatment.

OUTCOMES

Follow-up chest CT showed no significant abnormalities in the lungs 6 months after surgery.

LESSONS

To the best of our knowledge, our case may be the second reported case of a patient with LIP presenting with a ground glass nodule on chest CT, and it is speculated that the ground glass nodule may be an early manifestation of idiopathic LIP.

NKX2.1 mutation revealed by a lymphoid interstitial pneumonia in an adult with rheumatoid arthritis

This is the first case of a 37-year-old female patient carrier of a heterozygous NKX2.1 mutation associated with RA-ILD with a histological pattern of LIP. This case illustrates the wide panel of ILD subtypes associated with NKX2.1 mutations. https://bit.ly/3F49OTS.

Lymphangioleiomyomatosis and Other Cystic Lung Diseases

Cysts and cavities in the lung are commonly encountered on chest imaging. It is necessary to distinguish thin-walled lung cysts (≤2 mm) from cavities and characterize their distribution as focal or multifocal versus diffuse. Focal cavitary lesions are often caused by inflammatory, infectious, or neoplastic processes in contrast to diffuse cystic lung diseases. An algorithmic approach to diffuse cystic lung disease can help narrow the differential diagnosis, and additional testing such as skin biopsy, serum biomarkers, and genetic testing can be confirmatory. An accurate diagnosis is essential for the management and disease surveillance of extrapulmonary complications.

Primary Lymphoproliferative Lung Diseases: Imaging and Multidisciplinary Approach

Lymphoproliferative lung diseases are a heterogeneous group of disorders characterized by primary or secondary involvement of the lung. Primary pulmonary lymphomas are the most common type, representing 0.5–1% of all primary malignancies of the lung. The radiological presentation is often heterogeneous and non-specific: consolidations, masses, and nodules are the most common findings, followed by ground-glass opacities and interstitial involvement, more common in secondary lung lymphomas. These findings usually show a prevalent perilymphatic spread along bronchovascular bundles, without a prevalence in the upper or lower lung lobes. An ancillary sign, such as a “halo sign”, “reverse halo sign”, air bronchogram, or CT angiogram sign, may be present and can help rule out a differential diagnosis. Since a wide spectrum of pulmonary parenchymal diseases may mimic lymphoma, a correct clinical evaluation and a multidisciplinary approach are mandatory. In this sense, despite High-Resolution Computer Tomography (HRCT) representing the gold standard, a tissue sample is needed for a certain and definitive diagnosis. Cryobiopsy is a relatively new technique that permits the obtaining of a larger amount of tissue without significant artifacts, and is less invasive and more precise than surgical biopsy.

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.

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.

Sjögren's syndrome as a cause of both lymphoid interstitial pneumonia and light chain deposition disease in a single patient

A man in his 70s presents with 12 months of progressive dyspnoea, sicca symptoms and Raynaud's phenomenon. Serological testing and tear duct biopsy confirm Sjögren's syndrome (SS). Bilateral nodular-cystic appearances highly suggestive of lymphoid interstitial pneumonia (LIP) are noted on high-resolution computed tomography (HRCT), supported by a 40% lymphocytosis on bronchoalveolar lavage.Biopsy of a non-characteristic additional pulmonary nodule diagnoses light chain deposition disease (LCDD). Extrapulmonary organ involvement is excluded. Pulmonary function tests are well-preserved, and the patient is kept under active surveillance without requiring immunomodulatory treatment.LIP and LCDD both have a strong association with SS. Identification of these disease associations is crucial as they may result in multiorgan involvement or progression to haematological malignancy. This is the first case published in the literature and highlights that a pragmatic approach to investigations can avoid unnecessary procedures, and that treatment may be guided by symptomology.

Pulmonary lymphoproliferative disorders in children: a practical review

Pulmonary lymphoproliferative disorders represent an uncommon spectrum of proliferation of lymphoid tissue in the lung parenchyma ranging from benign hyperplasia to malignancy. They tend to occur in certain clinical situations and have typical imaging features that together can be used by the radiologist to suggest these entities as part of the differential diagnosis. We review key clinical, histopathological and computed tomography features of pulmonary lymphoproliferative disorders in children including follicular bronchiolitis, lymphoid interstitial pneumonia, granulomatous-lymphocytic interstitial lung disease, lymphoma and post-transplant lymphoproliferative disorder to familiarize the pediatric radiologist with this group of disorders.

Transformation of lymphoid interstitial pneumonia (LIP) into malignant lymphoma in patients with Sjogren's syndrome: a case report and literature review

Background

Lymphoid interstitial pneumonia (LIP) is a very rare disease and its malignant transformation is even more rare. LIP is easily misdiagnosed by clinicians and radiologists.

Case presentation

The medical record of a 64-year-old female with Sjogren's syndrome was reviewed. The clinical and pathological data along with chest CT images were obtained. The literature related to the transformation was reviewed. There were no specific clinical manifestations of LIP and its transformation into malignant lymphoma in the patient. The chest CT mainly displayed multiple cystic foci, with multiple nodules and ground-glass shadows in both lungs.

Conclusions

Malignant transformation to lymphoma is suspected with findings of large nodules (> 11 mm) or their sizes doubly increased, pleural effusion and alveolar consolidation.

Progressive lymphocytosis in familial hemophagocytic lymphohistiocytosis with lymphocytic interstitial pneumonia: a case report

Familial hemophagocytic lymphohistiocytosis (FHL) is a genetically heterogeneous disorder which is less typical in adults than pediatric patients. In this study, we reported a rare case of adult-onset FHL3 with progressive lymphocytosis and lymphocytic interstitial pneumonia (LIP). A 20-year old female was admitted to our institution for persistent cough with fever. A chest high-resolution computed tomography (HRCT) scan showed diffuse bilateral ground glass opacities (GGO). A lung biopsy revealed infiltration of lymphocyte in the pulmonary interstitium. The patient was treated with corticosteroids and immunosuppressants, followed by significant clinical improvement although lymphocytosis still persisted. The definitive diagnosis of FHL was based on whole genome sequencing by which heterozygous mutations in UNC13D gene were identified. Lymphocytosis may be a remarkable feature of some patients with FHL. Performing gene sequencing is important to improve the recognition of FHL to avoid misdiagnosis.

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Systemic lupus erythematosus presenting with lymphoid interstitial pneumonia as an initial manifestation

A 25-year-old woman with an extensive travel history developed chronic cough and multiple lung nodules. The lung biopsy revealed lymphoid interstitial pneumonia. The patient later developed cervical lymphadenopathy, arthritis and livedo reticularis, then systemic lupus erythematosus was diagnosed with positive double-stranded DNA and low complement. The patient's symptoms responded to prednisolone and azathioprine.

A Case of Progressive Dyspnea: Lymphocytic Interstitial Pneumonia in Collagen Vascular Disease

We describe an interesting rare case of a 61-year-old woman who was admitted to our hospital for exertional dyspnea, non-productive cough, and generalized weakness of six months duration. Her computed tomography was significant for ground-glass opacities combined with bibasilar consolidations and numerous pulmonary cysts. There can be a significant overlap in imaging findings of post-coronavirus disease 2019 (COVID-19) lung disease and interstitial lung disease from autoimmune diseases. We review in extensive detail the differential diagnosis for these imaging findings from a pulmonologist’s perspective and discuss investigations required for further workup. Our patient underwent transbronchial biopsy and was eventually diagnosed with lymphocytic interstitial pneumonia with Sjogren predominant mixed connective tissue disease. We also review in detail the current literature and prognosis for this interesting disease.

Idiopathic Interstitial Pneumonias: A Review of the Past and Emerging Therapies

PURPOSE

This article is an in-depth review of the complex classification, diagnosis, and treatment of idiopathic interstitial pneumonias (IIP), as well as emergence of new treatment options.

SUMMARY

Idiopathic interstitial pneumonias consist of various subgroup classifications that require expert analysis of imaging and histology to accurately diagnose this broad group of patients. Timely and accurate assessment of these patients is key in developing an appropriate pharmacological plan. The pathophysiology of IIP is not well understood but has been linked to an immune response resulting in inflammation, fibrosis, or proliferation of lung tissue which reduces lung function. Lung transplantation is currently the only curative option for treatment, but many new antiproliferative and immunosuppressive agents are being used to effectively slow the progression of lung dysfunction.

CONCLUSION

An often mixed radiological and histological pattern along with the invasive nature of biopsy for gold standard diagnosis create a challenge for the accurate identification of IIP. Further understanding of these idiopathic interstitial pneumonias will pave the way forward to the emergence of new treatment options and updates to standards of care.

Interstitial Lung Diseases and the Impact of Gender

Interstitial lung diseases encompass an amalgamated group of heterogeneous lung disorders, characterized by variable clinical and radiologic patterns. Despite an increase in our knowledge, pathogenesis of interstitial lung diseases remains largely unknown. Experimental evidence on the role of sex hormones in lung development and epidemiologic associations of gender differences with interstitial lung diseases prevalence fueled studies investigating the role of gender and sex hormones in the pathogenesis and treatment of pulmonary fibrosis. This review summarizes experimental and clinical data for the impact of gender and sex hormones on interstitial lung diseases and highlights future perspectives in the field.

Fibrotic Idiopathic Interstitial Lung Disease: The Molecular and Cellular Key Players

Interstitial lung diseases (ILDs) that are known as diffuse parenchymal lung diseases (DPLDs) lead to the damage of alveolar epithelium and lung parenchyma, culminating in inflammation and widespread fibrosis. ILDs that account for more than 200 different pathologies can be divided into two groups: ILDs that have a known cause and those where the cause is unknown, classified as idiopathic interstitial pneumonia (IIP). IIPs include idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP) known also as bronchiolitis obliterans organizing pneumonia (BOOP), acute interstitial pneumonia (AIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and lymphocytic interstitial pneumonia (LIP). In this review, our aim is to describe the pathogenic mechanisms that lead to the onset and progression of the different IIPs, starting from IPF as the most studied, in order to find both the common and standalone molecular and cellular key players among them. Finally, a deeper molecular and cellular characterization of different interstitial lung diseases without a known cause would contribute to giving a more accurate diagnosis to the patients, which would translate to a more effective treatment decision.

Interstitial Lung Disease in Connective Tissue Disease: A Common Lesion With Heterogeneous Mechanisms and Treatment Considerations

Connective tissue disease (CTD) related interstitial lung disease (CTD-ILD) is one of the leading causes of morbidity and mortality of CTD. Clinically, CTD-ILD is highly heterogenous and involves rheumatic immunity and multiple manifestations of respiratory complications affecting the airways, vessels, lung parenchyma, pleura, and respiratory muscles. The major pathological features of CTD are chronic inflammation of blood vessels and connective tissues, which can affect any organ leading to multi-system damage. The human lung is particularly vulnerable to such damage because anatomically it is abundant with collagen and blood vessels. The complex etiology of CTD-ILD includes genetic risks, epigenetic changes, and dysregulated immunity, which interact leading to disease under various ill-defined environmental triggers. CTD-ILD exhibits a broad spectra of clinical manifestations: from asymptomatic to severe dyspnea; from single-organ respiratory system involvement to multi-organ involvement. The disease course is also featured by remissions and relapses. It can range from stability or slow progression over several years to rapid deterioration. It can also present clinically as highly progressive from the initial onset of disease. Currently, the diagnosis of CTD-ILD is primarily based on distinct pathology subtype(s), imaging, as well as related CTD and autoantibodies profiles. Meticulous comprehensive clinical and laboratory assessment to improve the diagnostic process and management strategies are much needed. In this review, we focus on examining the pathogenesis of CTD-ILD with respect to genetics, environmental factors, and immunological factors. We also discuss the current state of knowledge and elaborate on the clinical characteristics of CTD-ILD, distinct pathohistological subtypes, imaging features, and related autoantibodies. Furthermore, we comment on the identification of high-risk patients and address how to stratify patients for precision medicine management approaches.

A 63-Year-Old Woman With an Acute Exacerbation of Interstitial Pneumonia

CASE PRESENTATION

A 63-year-old, non-smoking Asian woman presented to our hospital due to abnormal findings on chest radiography. She had no history of dust exposure. Chest radiography and CT imaging showed patchy ground-glass attenuation (GGA) in the bilateral lower lung lobes, a ground-glass nodule in the right lower lung lobe (diameter, 9.8 mm), and some thin-walled cysts in both lungs (Fig 1). Thickening of the interlobular septa, mediastinal lymphadenopathy, and pleural effusion were not evident. Video-assisted thoracic surgery was performed for the examination of the nodule and the background lung disease, and the nodule was histologically diagnosed as lung adenocarcinoma. Simultaneously, the lung background showed diffuse lymphocytic infiltration in the alveolar septum and peribronchovascular interstitium (Fig 2). There were no symptoms suggestive of autoimmune diseases such as dryness, arthralgia, skin rash, or fever. The patient was followed up without treatment for the interstitial lung disease.

Birt-Hogg-Dubé Syndrome presenting with chronic progressive dyspnea

Birt-Hogg-Dubé Syndrome (BHDS) is a rare autosomal dominant disease which manifests with cutaneous hamartomas, lung cysts and renal carcinomas. A wide spectrum of phenotypic expression and few visible manifestations makes BHDS a likely under-recognized entity. Diffuse cystic lung disease (DCLD) is the typical pulmonary manifestation of BHDS, which in the absence of other specific findings carries a broad differential diagnosis. Unlike many other causes of DCLD, BHDS is not known to present with symptomatic pulmonary dysfunction. We report a typical case of BHDS with an atypical presentation – chronic progressive dyspnea. The unusual presentation provides an opportunity to discuss the differential for DCLD and highlights the importance of maintaining an index of suspicion for BHDS even when symptoms appear inconsistent with the diagnosis. Also examined is the management of BHDS patients and their immediate relatives, and recommendations for the treatment of obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) given the potential risk of pneumothorax in this group.

Respiratory Manifestations in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by a wide spectrum of clinical manifestations. The respiratory system can be involved in up to 50-70% of patients and be the presenting manifestation of the disease in 4-5% of cases. Every part of the respiratory part can be involved, and the severity can vary from mild self-limiting to life threatening forms. Respiratory involvement can be primary (caused by SLE itself) or secondary (e.g., infections or drug toxicity), acute or chronic. The course, treatment and prognosis vary greatly depending on the specific pattern of the disease. This review article aims at providing an overview of respiratory manifestations in SLE along with an update about therapeutic approaches including novel biologic therapies.

Pharmacological Interventions for Pulmonary Involvement in Rheumatic Diseases

Among the diverse forms of lung involvement, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are two important conditions in patients with rheumatic diseases that are associated with significant morbidity and mortality. The management of ILD and PAH is challenging because the current treatment often provides only limited patient survival benefits. Such challenges derive from their common pathogenic mechanisms, where not only the inflammatory processes of immune cells but also the fibrotic and proliferative processes of nonimmune cells play critical roles in disease progression, making immunosuppressive therapy less effective. Recently, updated treatment strategies adopting targeted agents have been introduced with promising results in clinical trials for ILD ad PAH. This review discusses the epidemiologic features of ILD and PAH among patients with rheumatic diseases (rheumatoid arthritis, myositis, and systemic sclerosis) and the state-of-the-art treatment options, focusing on targeted agents including biologics, antifibrotic agents, and vasodilatory drugs.

[Cystic lung diseases]

Cystic lung diseases present uncommonly and have an undetermined incidence. Cysts result from a broad spectrum of causative mechanisms and diseases leading to variable clinical presentations. The pathogenic mechanisms that can lead to lung cyst formation include infection, neoplastic, systemic, traumatic, genetic and congenital processes. A rigorous, systemic and multidisciplinary approach is advised in the diagnostic workup of these conditions. In this article, we review cystic lung diseases including their presentation and management.

Sjogren's Syndrome and Pulmonary Disease

Sjogren's syndrome is an autoimmune connective tissue disease targeting the exocrine glands and frequently affecting the respiratory system. The pulmonary disease is the most important extra-glandular manifestation as it carries most of the morbidity and mortality. Typically, it affects the small airways ranging from mild to severe respiratory symptoms. The upper airways are also commonly involved, predisposing sinusitis to occur more frequently than in the normal population. Lymphocytic interstitial pneumonia was initially thought to be the prevailing parenchymal disease; however, multiple cohorts report non-interstitial pneumonia to be the most frequent subtype of interstitial lung disease. In the review of high-resolution computed tomography scans, cystic lesions are commonly found and associate with both the small airways and parenchymal disease. Under their presence, amyloidosis or lymphomas should be considered in the differential. Overall, Sjogren's syndrome has a higher risk for lymphoma, and in lungs this condition should be thought of, especially when the images reveal pulmonary nodularity, lymphocytic interstitial pneumonia and lymphadenopathy. Although, pulmonary artery hypertension was traditionally and exceptionally linked with Sjogren's syndrome, together with systemic lupus erythematosus, they are now acknowledged to be the most common pulmonary vascular disease in east Asian populations, even over patients with systemic sclerosis. Although there are no controlled prospective trials to treat pulmonary disease in Sjogren's syndrome, the mainstay treatment modality still falls on glucocorticoid therapy (systemic and inhaled), combined with immune modulators or alone. Most of the evidence sustains successful outcomes based on reported cases or case series.

A case of lymphocytic interstitial pneumonia presenting with a ground glass nodule as an initial finding

A 65-year-old woman had a ground glass nodule, which was suspicious for lung cancer, in her right lung S⁶ by chest computed tomography. For diagnosis, video-assisted thoracoscopic surgery was performed, and the specimen showed a pathological pattern of lymphocytic interstitial pneumonia (LIP). Four years after surgery, new localized ground glass shadows gradually increased on the base of the lung. However, because she had no respiratory symptoms and had normal respiratory function, she was observed with no medication. Subsequently, no other underlying diseases associated with LIP developed. The ground glass nodule was the initial lesion of LIP.

Lymphocytic interstitial pneumonia: computed tomography findings in 36 patients

Objective

To analyze the computed tomography (CT) findings of lymphocytic interstitial pneumonia (LIP).

Materials and Methods

We retrospectively reviewed the clinical and CT findings of 36 patients with LIP, including 25 women and 11 men, with a mean age of 52.5 years (age range, 22-78 years).

Results

The main associated diseases with LIP were Sjögren syndrome (42%), human immunodeficiency virus infection (17%), amyloidosis (17%), Sjögren syndrome associated with secondary amyloidosis (11%), idiopathic (8%), and systemic lupus erythematosus (5%). The predominant CT abnormalities were multiple cystic airspaces (n = 35), small nodules (n = 15), ground-glass opacities (n = 13), bronchiectasis and/or bronchiolectasis (n = 8), and thickening of the bronchovascular bundles (n = 8). Other CT findings included reticular opacities (n = 7), calcified nodules (n = 4), airspace consolidation (n = 4), emphysema (n = 3), honeycombing (n = 3), lymph node enlargement (n = 2), mosaic attenuation pattern (n = 1), and cavitated nodules (n = 1).

Conclusion

The main CT findings of LIP were multiple cysts, small nodules, and ground-glass opacities.

CT-guided biopsy in the differential diagnosis of Sjogren syndrome associated cystic lung disease: A case of lung nodular AL-k amyloidosis

Pulmonary involvement in Sjogren syndrome (SS) could manifest as cystic lung disease (CLD). CLD in SS includes lymphocytic interstitial pneumonia (LIP) and pulmonary amyloidosis. Differential diagnosis usually requires surgical lung biopsy, whereas CT-guided percutaneous fine needle aspiration biopsy (CT-FNAB) has not yet explored. We describe the case of a 63-year-old never smoker Caucasian female with a SS diagnosis who displayed a newly detected diffuse CLD at high-resolution computed tomography, though totally asymptomatic. Given the favorable location of one big lesion at the superior left lobe, a CT-FNAB was proposed instead of a more invasive SLB. At histology examination a diagnosis of pulmonary nodular AL kappa amyloidosis in the context of SS was established. In conclusion, CT-FNAB might represent an alternative and less invasive diagnostic procedure than SLB in the differential diagnosis of CLD, even if further research is needed. Moreover, this case presents an unusual association between SS and pulmonary nodular AL kappa amyloidosis, with pulmonary nodules and cysts without systemic manifestations.

Acute severe idiopathic lymphoid interstitial pneumonia: A case report

RATIONALE

Lymphoid interstitial pneumonia is a rare benign pulmonary lymphoproliferative disorder usually presenting with a sub-acute or chronic condition and frequently associated with autoimmune disorders, dysgammaglobulinemia, or infections.

PATIENT CONCERNS

A 74-year-old woman with no past medical history presented with acute dyspnea, nonproductive cough, hypoxemia (room air PaO2: 48 mmHg) and bilateral alveolar infiltrates with pleural effusion. Antibiotics and diuretics treatments did not induce any improvement. No underlying condition including cardiac insufficiency, autoimmune diseases, immunodeficiency, or infections was found after an extensive evaluation. Bronchoalveolar lavage revealed a lymphocytosis (60%) with negative microbiological findings. High-dose intravenous corticosteroids induced a mild clinical improvement only, which led to perform a surgical lung biopsy revealing a lymphoid interstitial pneumonia with no sign of lymphoma or malignancies.

DIAGNOSES

Acute severe idiopathic lymphoid interstitial pneumonia.

INTERVENTIONS

Ten days after the surgical lung biopsy, the patient experienced a dramatic worsening leading to invasive mechanical ventilation. Antibiotics and a new course of high-dose intravenous corticosteroids did not induce any improvement, leading to the use of rituximab which was associated with a dramatic clinical and radiological improvement allowing weaning from mechanical ventilation after 10 days.

OUTCOMES

Despite the initial response to rituximab, the patient exhibited poor general state and subsequent progressive worsening of respiratory symptoms leading to consider symptomatic palliative treatments. The patient died 4 months after the diagnosis of lymphoid interstitial pneumonia.

LESSONS

Idiopathic lymphoid interstitial pneumonia may present as an acute severe respiratory insufficiency with a potential transient response to rituximab.

Lung Involvement in Primary Sjögren's Syndrome-An Under-Diagnosed Entity

Interstitial lung disease (ILD) represents a frequent extra-glandular manifestation of primary Sjögren's Syndrome (pSS). Limited published data regarding phenotyping and treatment exists. Advances in managing specific ILD phenotypes have not been comprehensively explored in patients with coexisting pSS. This retrospective study aimed to phenotype lung diseases occurring in a well-described pSS-ILD cohort and describe treatment course and outcomes. Between April 2018 and February 2020, all pSS patients attending our Outpatient clinic were screened for possible lung involvement. Clinical, laboratory and high-resolution computed tomography (HRCT) findings were analyzed. Patients were classified according to HRCT findings into five groups: usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), desquamative interstitial pneumonia (DIP), combined pulmonary fibrosis and emphysema (CPFE), and non-specific-ILD. Lung involvement was confirmed in 31/268 pSS patients (13%). One-third (10/31) of pSS-ILD patients were Ro/SSA antibody negative. ILD at pSS diagnosis was present in 19/31 (61%) patients. The commonest phenotype was UIP n = 13 (43%), followed by NSIP n = 9 (29%), DIP n = 2 (6 %), CPFE n = 2 (6 %), and non-specific-ILD n = 5 (16%). Forced vital capacity (FVC) and carbon monoxide diffusion capacity (D_LCO) appeared lower in UIP and DIP, without reaching a significant difference. Treatment focused universally on intensified immunosuppression, with 13/31 patients (42%) receiving cyclophosphamide. No anti-fibrotic treatments were used. Median follow-up was 38.2 [12.4–119.6] months. Lung involvement in pSS is heterogeneous. Better phenotyping and tailored treatment may improve outcomes and requires further evaluation in larger prospective studies.

Characteristics of primary Sjögren's syndrome related lymphocytic interstitial pneumonia

Objective

This paper is aimed at investigating the clinical characteristics of primary Sjogren’s syndrome (pSS) with lymphocytic interstitial pneumonia (LIP).

Methods

The demographic data, clinical manifestations, laboratory and radiological findings, treatment, and prognosis from 15 cases of pSS-LIP patients were retrospectively analyzed. The data were compared with t test, χ² test, and Pearson/Spearman correlation analysis.

Results

(1) Fifteen cases of patients with pSS-LIP are all females (100%). Compared with pSS with interstitial lung disease(pSS-ILD) patients, the incidence of dry cough, dental caries is higher in pSS-LIP patients. The incidence of shortness of breath, weight loss, and crackles is lower in pSS-LIP patients than that of pSS-ILD patients. (2) Compared with pSS-ILD patients, pSS-LIP patients had higher percentage of patients with ANA, anti-SSA52KD antibody, anti-SSA60KD antibody, and anti-SSB antibody, and the higher concentration of serum globulin. (3) Compared with pSS-ILD patients, the frequency of obstructive ventilation dysfunction is significantly higher and the frequency of diffusion dysfunction is significantly lower in pSS-LIP patients. (4) The most frequent HRCT findings in patients with pSS-LIP is cysts (100%), followed by ground-glass opacities (73.3%), nodular shadow (73.3%) among the pSS-LIP patients. Compared with PSS-ILD patients, the incidence of pulmonary nodule shadow is significantly higher in PSS-LIP patients, while that of grid shadow was significantly lower. (5) Compared with the baseline, the sum of the number, maximum diameter, and diameter of cysts in three levels of pSS-LIP patients showed an increasing trend after treatment. (6) Correlation analysis: The changes of ground-glass opacities were positively correlated with using GC or not, and those were negatively correlated with the dose of GC treatment. Besides, there is a positive correlation between the annual change rate of the maximum diameter of cysts (△Ømax1/t) and the use of CTX; there is a positive correlation between the annual change rate of the total diameter of cysts (△Øsum1/t) and the use of CTX.

Conclusion

To the patients of pSS-LIP, female were more common than male, and the onset of LIP was usually more insidious. Hyperglobulinemia and anti-SSA antibody were more prominent in patients with pSS-LIP. Pulmonary function showed the higher rate of obstructive ventilation dysfunction and the lower rate of diffusion dysfunction. The appearance of ground-glass opacities in pSS-LIP patients suggests that the infiltration of inflammatory cells increases, which may cause airway compression, the expansion of terminal bronchioles, and the formation of cysts. The more ground-glass opacities appear earlier, and the more appearance of new cysts later. Therapy with glucocorticoid may be effective on the ground-glass opacity during acute stage, and therapy with cyclophosphamide may be effective on the cysts during chronic stage. The heavier ground-glass opacity is at baseline, the more likely it will recur during maintenance treatment. So follow-up closely is needed.

Key Points • It is the first clinical study with more cases of patients with pSS-LIP. • Female and hyperglobulinemia and anti-SSA antibody were more prominent in patients with pSS-LIP. • Pulmonary function showed the higher rate of obstructive ventilation dysfunction and the lower rate of diffusion dysfunction. • Therapy with glucocorticoid may be effective on the ground-glass opacity during acute stage, and therapy with cyclophosphamide may be effective on the cysts during chronic stage.

Investigating cystic lung disease: a respiratory detective approach

The cystic lung diseases are rare orphan lung disorders that most physicians will see infrequently in their everyday practice. Diagnostic and treatment options have improved over recent decades, with opportunities for slowing rate of progression and improving outcome for patients. This review provides a summary of the clinical approach to these lung disorders, including how to differentiate between different imaging patterns, clinical features, differential diagnosis and characteristics of the commonest presenting disorders.

Cystic lung diseases are uncommon disorders with a wide differential diagnosis. Treatment has improved over the last decade and respiratory physicians should feel encouraged to investigate such cases thoroughly to reach a final diagnosis.https://bit.ly/2W6Is9D

Pitfalls of Computed Tomography in the Coronavirus 2019 (COVID-19) Era: A New Perspective on Ground-Glass Opacities

Aim To study ground-glass opacities (GGO) not only from the coronavirus 2019 (COVID-19) pneumonia" perspective but also as a radiological presentation of other pathologies with comparable features. Methods We enrolled 33 patients admitted to Policlinico Universitario G. B. Rossi who underwent non-contrast-enhanced (NCE) or contrast-enhanced (CE) chest computed tomography (CT) between March 12 and April 12. All patients with CT-detected ground-glass opacity (GGO) were included. All patients resulted as COVID-19 negative at the reverse transcription-polymerase chain reaction (RT-PCR) assay. We studied the different pathologies underlying GGO features: neoplastic diseases and non-neoplastic diseases (viral pneumonias, interstitial pneumonias, and cardiopulmonary diseases) in order to avoid pitfalls and to reach the correct diagnosis. Results All CT scans detected GGOs. Symptomatic patients were 25/33 (75.7%). At the clinical presentation, they reported fever and dry cough; in six out of 25 cases, dyspnea was also reported (24%). Thirty-three (33; 100%) showed GGO at CT: 15/33 (45.45%) presented pure GGO, and 18/33 (54.54%) showed GGO with consolidation. The RT-PCR assay was negative in 100%. We investigated other potential underlying diseases to explain imaging features: neoplastic causes (8/33, 24.24%) and non-neoplastic causes, in particular, infectious pneumonias (16/33, 48,48 %, viral and fungal), interstitial pneumonias (4/33, 12,12%), and cardio-pulmonary disease (5/33, 15,15%). Conclusions GGO remains a diagnostic challenge. Although CT represents a fundamental diagnostic tool because of its sensitivity, it still needs to be integrated with clinical data to achieve the best clinical management. In the presence of typical imaging features (e.g. GGO and consolidation), the radiologist should focus on the pandemic and manage a suspect patient as COVID-19 positive until proven to be negative.

EBV-associated lymphoid interstitial pneumonia in IBD patient: Case report and literature review

Background

Lymphoid interstitial pneumonia (LIP) is categorized as a rare form of interstitial lung disease. Most cases are associated with autoimmune disease.

Case report

A 78-year-old male with Crohn's disease, presented with progressive dyspnea and dry cough for few weeks. The pathology of transbronchial lung biopsy was compatible with LIP and positive cells on EBER in situ hybridization. Blood EBV viral load was 85,715 copies/mL, compatible with EBV-associated LIP. All immunosuppressive agents were discontinued, but unfortunately the patient died due to hospital-acquired infections. In addition, we reviewed all reported cases of EBV-associated LIP in literature.

Conclusions

To our knowledge, we report herein the first case of EBV-associated LIP in an IBD patient. We postulate that LIP was the consequence from EBV reactivation, probably due to immunosuppressive agents and/or IBD itself. The physician should aware of this disease when taking care of immunosuppressive patients who present with acute interstitial pneumonitis.