Diffuse cystic lung diseases: differential diagnosis

Cystic Lung Disease Presenting as Recurrent Non-traumatic Chylothorax: Case Report and a Mini-Review

Malignancy and infections are the most common causes of recurrent chylothorax. Cystic lung disease, especially sporadic pulmonary lymphangioleiomyomatosis (LAM), is a rare condition that may manifest as recurrent chylothorax. We present a case of a 42-year female who presented with dyspnea on exertion secondary to recurrent chylothorax, requiring three thoracenteses within a few weeks. Chest imaging showed multiple bilateral thin-walled cysts. Thoracentesis revealed milky-colored pleural fluid, which was exudative and lymphocytic predominant. Infectious, autoimmune, and malignancy workup was negative. Vascular endothelial growth factor-D (VEGF-D) levels were sent for testing, which came back elevated (2001 pg/ml). A presumptive diagnosis of LAM was made based on recurrent chylothorax, bilateral thin-walled cysts, and elevated VEGF-D levels in a reproductive age group woman. Given quick reaccumulation of chylothorax, she was started on sirolimus. After initiating therapy, there was a significant improvement in the patient's symptoms, with no recurrence of chylothorax in the five years of follow-up. Awareness of different forms of cystic lung diseases is vital to establish an early diagnosis, which may prevent disease progression. Rarity and heterogeneity of presentation often make the diagnosis challenging, requiring a high degree of suspicion.

Diffuse cystic lung disease caused by tuberculosis infection: Case series

Diffuse cystic lung disease (DCLD) is a complex disease that can be caused by various reasons. Although the chest CT scan plays a vital role in suggesting the etiology of DCLD, it is apt to lead to misdiagnosis simply based on the CT image of the lung. Here, we report a rare case of DCLD caused by tuberculosis and misdiagnosed as pulmonary Langerhans cell histiocytosis (PLCH). A 60-year-old female DCLD patient with a long-term smoking history was admitted to the hospital because of a dry cough and dyspnea, and the chest CT scan showed diffuse irregular cysts in both lungs. We considered the patient to be PLCH. To alleviate dyspnea, we chose to give her intravenous glucocorticoids. However, she developed a high fever during the use of glucocorticoids. We performed flexible bronchoscopy and bronchoalveolar lavage. Mycobacterium tuberculosis (specific sequence reads: 30) was detected in BALF. She was finally diagnosed with pulmonary tuberculosis. Tuberculosis infection is one of the rare causes of DCLD. We have discovered thirteen similar cases by searching Pubmed and Web of Science. For DCLD patients, glucocorticoids should not be used blindly unless the existence of a tuberculosis infection is ruled out. TBLB for pathology and bronchoalveolar lavage fluid (BALF) for microbiological detection are helpful for diagnosis.

Tomographic pleuropulmonary manifestations in rheumatoid arthritis: a pictorial essay

Rheumatoid arthritis (RA) is an autoimmune inflammatory and heterogeneous disease that affects several systems, especially the joints. Among the extra-articular manifestations of RA, pleuropulmonary involvement occurs frequently, with different presentations, potentially in all anatomic thoracic compartments, and may determine high morbidity and mortality. The most common pleuropulmonary manifestations in patients with RA include interstitial lung disease (ILD), pleural disease, pulmonary arterial hypertension, rheumatoid lung nodules, airway disease (bronchiectasis and bronchiolitis), and lymphadenopathy. Pulmonary hypertension and ILD are the manifestations with the greatest negative impact in prognosis. HRCT of the chest is essential in the evaluation of patients with RA with respiratory symptoms, especially those with higher risk factors for ILD, such as male gender, smoking, older age, high levels of rheumatoid factor, or positive anti-cyclic citrullinated peptide antibody results. Additionally, other etiologies that may determine tomographic pleuropulmonary manifestations in patients with RA are infections, neoplasms, and drug-induced lung disease. In these scenarios, clinical presentation is heterogeneous, varying from being asymptomatic to having progressive respiratory failure. Knowledge on the potential etiologies causing tomographic pleuropulmonary manifestations in patients with RA coupled with proper clinical reasoning is crucial to diagnose and treat these patients.

Successful Chemotherapy for Diffuse Cystic Lung Metastases during Targeted Therapy with Osimertinib in a Patient with Non-Small-Cell Lung Cancer: A Literature Review and a Rare Case Report

Introduction

Diffuse lung cysts occur owing to several diseases; however, diffuse cystic lung metastases are very rare in the case of lung cancer. We report a rare case of diffuse cystic lung metastases from lung adenocarcinoma and reviewed previously reported cases of cystic lung metastases for lung cancer and determined their characteristics.

Case Presentation

A 78-year-old Japanese woman with advanced lung adenocarcinoma was positive for the epidermal growth factor receptor gene mutation exon 21 L858R and had been treated with osimertinib. She presented with multiple bilaterally positioned thin-walled lung cysts and pneumothorax. Lung cysts were diagnosed as cystic lung metastases from lung cancer, and carboplatin, pemetrexed, and pembrolizumab were subsequently administered. All cysts markedly decreased in size, and some disappeared.

Conclusion

Effective treatment methods for cystic lung metastases from lung cancer have not been reported. To our knowledge, this is the first case of cystic lung metastases that were successfully treated with chemotherapy.

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.

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma presented as cystic lung disease – a case report in Tuen Mun Hospital Hong Kong

We report a rare case of pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) in a 52-year-old woman presented as cystic lung disease together with ground-glass lesion on computed tomography (CT) of the thorax incidentally found as part of workup for organ donation.

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.

Fibrotic Cystic Lung Disease Post Hematopoietic Stem Cell Transplant: Who is the Culprit?

Pulmonary complications post hematopoietic stem cell transplant (HSCT) are associated with poor outcomes and require extensive management depending on the etiology. They usually present in the form of bronchiolitis obliterans syndrome, interstitial pneumonitis, or drug toxicity that can lead to fibrosis. Scant data exists regarding diffuse cystic lung disease following HSCT, and the existing literature only mentions mild cystic changes. We present the case of a 25-year-old man with stage IVB Hodgkin's lymphoma post allogeneic HSCT, who developed progressive traction bronchiectasis, with the appearance of extensive pulmonary cysts that followed significant fibrotic changes and discuss the possible etiologies behind it.

Pictorial review of computed tomography features of diffuse cystic lung disease

Diffuse cystic lung disease represents a diverse group of uncommon disorders that has been increasingly diagnosed due to the increasing use of computed tomography. It poses a frequent diagnostic challenge to radiologists due to the similar clinical and radiological features these diseases share. This pictorial review includes selected cases from the Hospital Authority New Territories West Cluster (NTWC) in Hong Kong from the past 3 years. It will illustrate the spectrum of diffuse cystic lung diseases, including some rarer entities in our locality, and identify the pertinent differentiating imaging features on CT. A flowchart to summarize these features is provided at the end to aid in diagnosis.

Association between pulmonary artery to aorta diameter ratio with pulmonary hypertension and outcomes in diffuse cystic lung diseases

To investigate the importance of pulmonary vascular measurements on computed tomography (CT) in predicting pulmonary hypertension (PH) and worse outcomes in diffuse cystic lung diseases (DCLDs).We conducted a cross-sectional study of patients with DCLDs. Patients underwent pulmonary function tests, a six-minute walk test (6MWT), chest CT, transthoracic echocardiography, and right heart catheterization. Pulmonary artery (PA) diameter and PA-ascending aorta ratio (PA-Ao ratio) were obtained from CT. Mean pulmonary artery pressure (mPAP) from right heart catheterization was correlated with tomographic, functional, and echocardiographic variables. The association between the PA-Ao ratio with outcomes was determined by Kaplan-Meier curves.Thirty-four patients were included (18 with pulmonary Langerhans cell histiocytosis and 16 with lymphangioleiomyomatosis, mean age 46 ± 9 years). Forced expiratory volume in the first second and lung diffusing capacity for carbon monoxide were 47 ± 20% and 38 ± 21% predicted, respectively. PA diameter and PA-Ao ratio were 29 ± 6 mm and 0.95 ± 0.24, respectively. PA-Ao ratio > 1 occurred in 38.2% of patients. PA-Ao ratio was a good predictor of PH. mPAP correlated best with PA-Ao ratio, PA diameter, oxygen desaturation during six-minute walk test, and echocardiographic variables. Patients with PA-Ao ratio > 1 had greater mPAP, and a higher risk of death or lung transplantation (log-rank, P < .001) than those with PA-Ao ratio ≤ 1.The PA-Ao ratio measured on CT scan has a potential role as a non-invasive tool to predict the presence of PH and as a prognostic parameter in patients with DCLDs.

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.

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.

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.

Birt-Hogg-Dubé syndrome presenting with spontaneous pneumothorax and extensive pulmonary cysts in the absence of skin lesions or renal pathology

Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition which classically manifests with skin lesions such as fibrofolliculomas, pulmonary cysts that predispose to spontaneous pneumothorax and an increased risk of developing renal cell carcinoma. We describe the case of a patient who presented with a spontaneous pneumothorax on a background of multiple lung cysts, in the absence of cutaneous fibrofolliculomas and renal tumours. A germline mutation in the folliculin FLCN gene was subsequently identified, confirming BHD syndrome. Our case highlights the importance of considering a broad differential diagnosis for the cause of a spontaneous pneumothorax in the presence of unexplained cystic lung disease and emphasises the value of maintaining a high index of clinical suspicion for inherited causes of pneumothoraces.

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.

Difficult diagnosis and rare morphology of lymphangioleiomyomatosis with giant cysts

We report on a 32-year-old woman with a second manifestation of a tension pneumothorax two weeks after drainage therapy. The chest CT-scan revealed multiple large bilateral pulmonary cysts. She underwent minimally invasive wedge resection and pleurectomy for treatment. The extensive histologic evaluation revealed the diagnosis of a lymphangioleiomyomatosis (LAM) with an uncommon pattern of lung cysts. Initial staining for HMB-45 was negative. Repeated evaluation of other sections and reference pathology examination detected minimal expression of HMB-45. This case illustrates that immunohistochemistry for HMB-45 may be negative, although LAM is present and repeated immunohistochemistry may be necessary to establish the correct diagnosis.

Computed tomography in hypersensitivity pneumonitis: main findings, differential diagnosis and pitfalls

INTRODUCTION

Hypersensitivity pneumonitis (HP) is a disease with variable clinical presentation in which inflammation in the lung parenchyma is caused by the inhalation of specific organic antigens or low molecular weight substances in genetically susceptible individuals. Alterations of the acute, subacute and chronic forms may eventually overlap, and the diagnosis based on temporality and presence of fibrosis (acute/inflammatory HP vs. chronic HP) seems to be more feasible and useful in clinical practice. Differential diagnosis of chronic HP with other interstitial fibrotic diseases is challenging due to the overlap of the clinical history, and the functional and imaging findings of these pathologies in the terminal stages. Areas covered: This article reviews the essential features of HP with emphasis on imaging features. Moreover, the main methodological limitations of high-resolution computed tomography (HRCT) interpretation are discussed, as well as new perspectives with volumetric quantitative CT analysis as a useful tool for retrieving detailed and accurate information from the lung parenchyma. Expert commentary: Mosaic attenuation is a prominent feature of this disease, but air trapping in chronic HP seems overestimated. Quantitative analysis has the potential to estimate the involvement of the pulmonary parenchyma more accurately and could correlate better with pulmonary function results.