An unusual case of metastatic trophoblastic neoplasm presenting with diffuse cystic lung disease and pulmonary artery pseudoaneurysms in a teenager

Diffuse cystic lung diseases (DCLDs) are a diverse group of lung disorders characterized by the presence of multiple air filled cysts within the lung tissue. These cysts are thin walled and surrounded by normal lung tissue. In adults, DCLD can be associated with various conditions such as lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis, cancers, and more. In children, DCLD is often linked to lung developmental abnormalities, with bronchopulmonary dysplasia being a common cause. Patients with pulmonary cysts are typically asymptomatic, but some may experience mild symptoms or pneumothorax. While DCLD in children is rarely due to malignancy, metastatic lung disease can be a cause. It is important for clinicians to be aware of the possibility of metastatic lung disease when encountering DCLD.

Pulmonary interstitial glycogenosis in Birt-Hogg-Dubé syndrome-associated lung cysts: A new insight into the pathogenesis?

Multiple lung cysts are one of the major features of Birt-Hogg-Dubé syndrome (BHD), but little is known about their nature and pathogenesis. We report a case of a woman diagnosed with BHD lung cysts who exhibited pulmonary interstitial glycogenosis (PIG), a mesenchymal abnormality hitherto undescribed in this disease, in specimens resected at 14 and 29 years of age. Histopathologically, oval to spindle clear cells were seen in the subepithelial interstitial tissue of septal structures and the walls of the cysts. They had abundant periodic acid-Schiff-positive cytoplasmic glycogen. Immunohistochemically, these cells were positive for a few markers of mesenchymal stem cell-like lineage, including vimentin, CD44, and CD10, and negative for markers of epithelial or specific mesenchymal differentiation; these results were consistent with the reported immunophenotype of PIG cells. These PIG cells were more abundant in her specimen at age 14 years than in the second specimen from adulthood. The present case suggests that BHD lung cysts belong to a group of pulmonary developmental disorders characterized by combined PIG and alveolar simplification/cystic change. Disorders with PIG may persist until adulthood and may be of clinical and pathological significance.

Exploring bilateral pneumothorax leading to a rare diagnosis in a young lady

Bilateral pneumothorax is a rare occurrence and vigilant clinical examination is mandatory to suspect that during the presentation. This case illustrates a young lady presented with bilateral pneumothorax, new identification of lung cysts and chylous pleural effusion leading to diagnosis of lymphangioleiomyomatosis.

Recommendations on scuba diving in Birt-Hogg-Dubé syndrome

INTRODUCTION

Although very uncommon, severe injury and death can occur during scuba diving. One of the main causes of scuba diving fatalities is pulmonary barotrauma due to significant changes in ambient pressure. Pathology of the lung parenchyma, such as cystic lesions, might increase the risk of pulmonary barotrauma.

AREAS COVERED

Birt-Hogg-Dubé syndrome (BHD), caused by pathogenic variants in the FLCN gene, is characterized by skin fibrofolliculomas, an increased risk of renal cell carcinoma, multiple lung cysts and spontaneous pneumothorax. Given the pulmonary involvement, in some countries patients with BHD are generally recommended to avoid scuba diving, although evidence-based guidelines are lacking. We aim to provide recommendations on scuba diving for patients with BHD, based on a survey of literature on pulmonary cysts and pulmonary barotrauma in scuba diving.

EXPERT OPINION

In our opinion, although the absolute risks are likely to be low, caution is warranted. Given the relative paucity of literature and the potential fatal outcome, patients with BHD with a strong desire for scuba diving should be informed of the potential risks in a personal assessment. If available a diving physician should be consulted, and a low radiation dose chest computed tomography (CT)-scan to assess pulmonary lesions could be considered.

Pulmonary Langerhans Cell Histiocytosis Masquerading as Lymphangioleiomyomatosis

Pulmonary Langerhans cell histiocytosis (PLCH) is an uncommon lung disease that affects young adults aged 20 to 40 years with current or prior history of smoking. The pathologic cell type in PLCH is a dendritic cell of the monocyte-macrophage line that resembles cutaneous Langerhans cells. This report presents the case of a 42-year-old woman with PLCH. We discuss her clinical symptoms, diagnostic tests, and treatment plan, with a specific focus on the radiologic features. The patient exhibited a radiologic appearance similar to that of lymphangiomyomatosis with histologic evidence of PLCH.

Cystic Lung Changes in Down Syndrome: A Case Report

A wide spectrum of multi-organ complications have been associated with Down syndrome. Pulmonary complications are a leading cause of morbidity and mortality in Down syndrome. A four-year-old boy with Down syndrome presented to our emergency department with a cough and shortness of breath. He had signs of respiratory distress and decreased air entry in the right lung. A chest radiograph revealed airspace opacity and an air bronchogram in the right lung, both consistent with pneumonia. Oxygen saturation was not maintained on a non-rebreather mask, and the patient required admission to the intensive care unit, where he underwent intubation and mechanical ventilation. With the aggressive antibiotic therapy, the patient had improvements in terms of laboratory and radiographic findings. However, clinical symptoms persisted. Hence, a computed tomography (CT) scan was performed, which demonstrated findings of pulmonary edema and unexpected findings of subpleural cystic lung changes bilaterally with significant replacement of the right middle lobe with these cysts. Initially, these cysts caused significant confusion for the treating physicians and were misinterpreted as honeycombing changes related to end-stage lung disease. However, radiologists confirmed the incidental nature of these cysts in patients with Down syndrome. Appropriate recognition of this entity is crucial to avoid its misinterpretation, which may cause unnecessary laboratory and radiological investigations.

Renal and Lung Cysts in Birt-Hogg-Dubé Syndrome: A Continuum of the Same Disorder

Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal-dominant disorder, affecting multiple organs, mostly the skin, lungs, and kidneys. The prevalence of BHD syndrome is difficult to define given the rarity of the disease. Patients present most often with primary spontaneous pneumothorax. Renal tumors are a characteristic finding in BHD, and are often bilateral and multifocal and of the chromophobe and oncocytoma variant. Very scarce reports have highlighted the presence of simple renal cysts, as the only phenotypical renal manifestation, in BHD patients. Herein, we highlight two novel cases of bilateral multiple renal and pelvic cysts, in two females with genetically proven BHD syndrome, doubting a potential association with BHD syndrome.

Managing Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.

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.

Birt-Hogg-Dubé syndrome - an unique case series

Birt-Hogg-Dubé syndrome (BHDS) is an uncommon autosomal dominant syndrome. It is also known as Hornstein-Knickenberg syndrome. It is an inherited disorder culminating in mutations in folliculin coding gene (FLCN). The clinical exhibitions of the syn-drome are multi-systemic, comprising of a constellation of pulmonary, dermatologic and renal system manifestations. The most common presentations include fibrofolliculomas, renal cell carcinomas, lung cysts and spontaneous pneumothorax. The treatment is conservative with regular monitoring of the renal and lung parameters. Fibrofolliculomas may require surgical excision and recurrent events of pneumothorax may warrant pleurodesis. We reported a case series of 2 patients presenting with symptoms of progressive breathlessness along with dermatological manifestations and subsequently showing radiological manifestations of Birt-Hogg-Dubé syndrome in the form of lung cysts.

Birt-hogg-Dubé Syndrome Incidentally Identified in a Potential Liver Donor

BACKGROUND

Birt-Hogg-Dubé Syndrome (BHDS), an autosomal dominant hereditary condition, occurs due to mutations in the gene encoding folliculin (FLCN) in the short arm of the 17th chromosome characterized by lung cysts with specific skin findings and renal cell carcinoma. Patients have usually complaints related to dyspnea and chest pain due to pneumothorax but they may be asymptomatic due to wide phenotypic heterogeneity. Herein, we report the imaging findings of a case 32-year-old male with BHDS without any symptom who was diagnosed incidentally by computed tomography (CT) due to organ donation.

CASE REPORT

In a 32-year-old male patient evaluated as a potential liver donor, CT was performed for preoperative preparation. The patient's medical history was unremarkable. In the CT examination, multiple air cysts of different sizes in both lungs were observed and also, a 7-cm solid renal mass of the right kidney was observed in the dynamic examination. Due to a large number of lung cysts and the presence of solid renal tumors at a young age, BHDS was considered. The patient underwent partial nephrectomy, and the pathology result was hybrid oncocytic-chromophobe renal cell carcinoma. In the genetic examination, a heterozygous germline mutation was detected in the 11th exon of the FLCN gene.

CONCLUSION

While potential organ donors are generally healthy and asymptomatic individuals, incidental lesions can be detected in the donor organ or other organs in the examination area during radiological imaging. Although most incidental lesions are benign, important clinical conditions can rarely be observed, as in our case. Familial and syndromic conditions should also be considered for the presence of solid renal masses incidentally detected at a young age. To the best of our knowledge, this is the first reported case of BHDS in English literature who was diagnosed incidentally on computed tomography for being a living liver donor.

Pulmonary Function in Patients With Multiple Endocrine Neoplasia 2B

CONTEXT

Multiple endocrine neoplasia type 2B (MEN2B) is a rare cancer predisposition syndrome resulting from an autosomal-dominant germline mutation of the RET proto-oncogene. No prior studies have investigated pulmonary function in patients with MEN2B.

OBJECTIVE

This study characterized the pulmonary function of patients with MEN2B.

DESIGN

This is a retrospective analysis of pulmonary function tests (PFTs) and chest imaging of patients enrolled in the Natural History Study of Children and Adults with MEN2A or MEN2B at the National Institutes of Health.

RESULTS

Thirty-six patients with MEN2B (18 males, 18 females) were selected based on the availability of PFTs; 27 patients underwent at least 2 PFTs and imaging studies. Diffusion abnormalities were observed in 94% (33/35) of the patients, with 63% (22/35) having moderate to severe defects. A declining trend in diffusion capacity was seen over time, with an estimated slope of -2.9% per year (P = 0.0001). Restrictive and obstructive abnormalities were observed in 57% (20/35) and 39% (14/36), respectively. Computed tomography imaging revealed pulmonary thin-walled cavities (lung cysts) in 28% (9/32) of patients and metastatic lung disease in 34% (11/32) of patients; patients with metastatic lung lesions also tended to have thin-walled cavities (P = 0.035).

CONCLUSIONS

This study characterized pulmonary function within a MEN2B cohort. Diffusion, restrictive, and obstructive abnormalities were evident, and lung cysts were present in 28% of patients. Further research is required to determine the mechanism of the atypical pulmonary features observed in this cohort.

Expanding the phenotype of COPA syndrome: a kindred with typical and atypical features

Background

Copa syndrome is a rare autosomal dominant disorder with abnormal intracellular vesicle trafficking. The objective of this work is to expand the knowledge about this disorder by delineating phenotypic features of an unreported COPA family.

Methods and results

A heterozygous missense variant (c.698 G>A, p.Arg233His) in COPA was identified in four members of a three-generation kindred with lung, autoimmune and malignant disease of unknown aetiology. Ages of onset were 56, 26, 16 and 1 year, with earlier age of onset in successive generations. Presenting symptoms were cough and dyspnoea. Findings included small lung cysts, follicular bronchiolitis, interstitial lung disease, neuroendocrine cell hyperplasia, rheumatoid arthritis, avascular necrosis and select abnormal autoimmune serologies. Neither alveolar haemorrhage nor glomerular disease were present. Features not previously associated with Copa syndrome included neuromyelitis optica, pulmonary carcinoid tumour, clear cell renal carcinoma, renal cysts, hepatic cysts, nephrolithiasis, pyelonephritis and meningitis. Longitudinal evaluations demonstrated slow progression of lung disease and extrapulmonary cysts.

Conclusions

Worsening severity with successive generations may be observed in Copa syndrome. Extrapulmonary cysts, malignancies, autoimmune neurological disorders and infections are clinical features that may be associated with Copa syndrome. Further studies are indicated to fully define the phenotypic spectrum of this disorder.

Cystic Lung Diseases: Algorithmic Approach

Cysts are commonly seen on CT scans of the lungs, and diagnosis can be challenging. Clinical and radiographic features combined with a multidisciplinary approach may help differentiate among various disease entities, allowing correct diagnosis. It is important to distinguish cysts from cavities because they each have distinct etiologies and associated clinical disorders. Conditions such as emphysema, and cystic bronchiectasis may also mimic cystic disease. A simplified classification of cysts is proposed. Cysts can occur in greater profusion in the subpleural areas, when they typically represent paraseptal emphysema, bullae, or honeycombing. Cysts that are present in the lung parenchyma but away from subpleural areas may be present without any other abnormalities on high-resolution CT scans. These are further categorized into solitary or multifocal/diffuse cysts. Solitary cysts may be incidentally discovered and may be an age related phenomenon or may be a remnant of prior trauma or infection. Multifocal/diffuse cysts can occur with lymphoid interstitial pneumonia, Birt-Hogg-Dubé syndrome, tracheobronchial papillomatosis, or primary and metastatic cancers. Multifocal/diffuse cysts may be associated with nodules (lymphoid interstitial pneumonia, light-chain deposition disease, amyloidosis, and Langerhans cell histiocytosis) or with ground-glass opacities (Pneumocystis jirovecii pneumonia and desquamative interstitial pneumonia). Using the results of the high-resolution CT scans as a starting point, and incorporating the patient's clinical history, physical examination, and laboratory findings, is likely to narrow the differential diagnosis of cystic lesions considerably.

Pulmonary interstitial cholesterol crystals associated with diffuse lung cysts in adult: a case report and literature review

BACKGROUND

Cholesterol pneumonitis or endogenous lipoid pneumonia (ELP) result from the accumulation of endogenous cholesterol esters in the lungs, leading to a fibroblastic interstitial inflammatory process, and may be complicated by a secondary bacterial or fungal infection. Striking features were cholesterol clefts in the alveolar and interstitial spaces and alveolar wall-thickening with lymphocytic infiltrations, which was called pulmonary interstitial and intra-alveolar cholesterol granulomas (PICG).

CASE PRESENTATION

We report a case of pneumothorax with diffuse lung cysts and pulmonary interstitial cholesterol in a 26-year-old woman. Our case is unique because development of PICG or ELP has been observed in children, but rarely in adult. Most cases could be linked to exogenous sources like inhalation of lipid material or gastroesophageal reflex (GER). In our case, no signs of GER could be discovered. Diffuse lung cysts coexisting with pulmonary interstitial cholesterol crystals are never reported. Additionally, no multinucleated giant cells or granuloma are found pathologically, which make the diagnosis of PICG or lipoid pneumonia difficult.

CONCLUSIONS

Pulmonary interstitial cholesterol crystals may develop gradually and evenly distributed throughout the entire lung and resulted in severe distortion of the native structure of the lung.

Diffuse Cystic Lung Disease. Part I

The diffuse cystic lung diseases (DCLDs) are a group of pathophysiologically heterogenous processes that are characterized by the presence of multiple spherical or irregularly shaped, thin-walled, air-filled spaces within the pulmonary parenchyma. Although the mechanisms of cyst formation remain incompletely defined for all DCLDs, in most cases lung remodeling associated with inflammatory or infiltrative processes results in displacement, destruction, or replacement of alveolar septa, distal airways, and small vessels within the secondary lobules of the lung. The DCLDs can be broadly classified according to underlying etiology as those caused by low-grade or high-grade metastasizing neoplasms, polyclonal or monoclonal lymphoproliferative disorders, infections, interstitial lung diseases, smoking, and congenital or developmental defects. In the first of a two-part series, we present an overview of the cystic lung diseases caused by neoplasms, infections, smoking-related diseases, and interstitial lung diseases, with a focus on lymphangioleiomyomatosis and pulmonary Langerhans cell histiocytosis.

Recurrent bilateral spontaneous pneumothorax secondary to lung adenocarcinoma with epidermal growth factor receptor mutation

A 42‐year‐old female patient was admitted for recurrent bilateral spontaneous pneumothorax. High resolution computed tomography showed bilateral pneumothorax and numerous round and oval, thin‐walled lung cysts. Microscopically, each small cyst was composed of distended subpleural alveolar spaces. Tumor cells, characteristic of acinar adenocarcinoma, obstructed and narrowed the terminal bronchioles. There was no tumor necrosis or mucin production. This suggested check‐valve as a possible mechanism of the thin‐walled cysts and pneumothorax. Genetic analysis suggested that the tumors were positive for epidermal growth factor receptor mutation L858R in exon 21. Bilateral spontaneous pneumothorax and thin‐walled cysts in association with lung cancer is rarely reported and may be confused with cystic benign lung lesions.

Judicious DICER1 testing and surveillance imaging facilitates early diagnosis and cure of pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB) and Sertoli-Leydig cell tumor (SLCT) are both associated with germline mutations in DICER1. In this brief report, a maternal history of SLCT led to identification of a deleterious DICER1 mutation in the patient and her asymptomatic infant. Radiographic screening revealed a large Type I PPB, which was completely resected. Identification of DICER1 mutation carriers and imaging of children at risk for PPB may allow detection of PPB in its earliest and most curable form, leading to increased likelihood of surgical cure and decreased risks of treatment-related late effects.

Persistent pulmonary interstitial emphysema in a case of Langerhans cell histiocytosis

We present the case of a 10-month-old boy with multisystem Langerhans cell histiocytosis showing thin-walled lung cysts along with computed tomography (CT) evidence of persistent pulmonary interstitial emphysema (PPIE), in the absence of pneumothorax or pneumomediastinum. Follow-up CT performed after 6 months demonstrated complete resolution of interstitial emphysema.