Pulmonary langerhans cell histiocytosis

Smoking-Related Interstitial Lung Disease: Historical Perspective and Advances in the Twenty-first Century

In the twenty- first century, there is widespread agreement that in addition to lung cancer, emphysema, and chronic bronchitis, cigarette smoking causes accumulation of pigmented macrophages, interstitial fibrosis, and Langerhans cell proliferation in various permutations. These histologic changes remain subclinical in some patients and produce clinical manifestations and imaging abnormalities in others. Debate surrounds terminology of these lesions, which are often grouped together under the umbrella of "smoking-related interstitial lung disease." This review summarizes modern concepts in our understanding of these abnormalities and explains how the recognition of smoking-related interstitial fibrosis has advanced the field.

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.

Evaluation of the Interstitial Histological Lesions in Pulmonary Langerhans Cell Histiocytosis

OBJECTIVE

Pulmonary Langerhans cell histiocytosis is a cystic lung disease characterized by the proliferation of parenchymal dendritic cells. The disease can become chronic or even cause pulmonary fibrosis. Our aim in this study was to investigate the typical histological findings and interstitial fibrosis in pulmonary Langerhans cell histiocytosis cases.

MATERIAL AND METHOD

In the study, cases that had undergone diagnostic resection were screened. Smoking, histological stage (subacute, subacute-chronic), and cystic and eosinophilic granulomas were confirmed in the cases. In addition to emphysema, chronic nonspecific bronchiolitis, interstitial fibrosis (subpleural-paraseptal fibrosis, peribronchial fibrosis, fibrotic nonspecific interstitial pneumonia), honeycomb-type fibrocysts, and unexpected lesions were investigated. Descriptive and comparative (Fisher exact test) statistical analyses were used in the study (p < 0.05).

RESULTS

A total of 27 cases were detected; age distribution was 17-68 (36.4). Smoking was present in 15 (55.5%) cases. Six (22.2%) cases were subacute, and 21 (7.7%) cases were subacute-chronic histological stage. A cystic lesion was present in 22 (81.4%) cases. All cases had emphysema accompanying the underlying lesions. Chronic nonspecific bronchiolitis was detected in 14 (51.8%) cases. Interstitial fibrosis was detected in 8 (29.6%) patients. Compared to interstitial fibrosis and nonfibrosis, there was no significant difference between being younger than 39 years, gender, smoking, and histological stage (p=0.41; 1; 0.69; 0.63, respectively).

CONCLUSION

There is a risk of developing interstitial fibrosis patterns and honeycomb-type fibrocysts in the progression of pulmonary Langerhans cell histiocytosis. Histopathological evaluation can play an important role in the detection of risk groups.

Multiple cystic lung disease in a smoker

Background

Pulmonary cyst is a rounded lung parenchymal lucency, usually containing air or fluid. Approach to establishing the etiology of lung cyst includes determining their location, number, distribution, and presence or absence of associated computed tomography findings (associated with nodules or ground-glass attenuation). Multiple cysts may be seen in various diseases, and radiological imaging is the usual starting point in detecting lung cysts. Importance of adequate clinical examination accompanied with relevant investigations in securing the etiology of lung cysts cannot be overemphasized. We present a first case of a rare multiple cystic lung disease from the Kingdom of Bahrain that was successfully managed with oral corticosteroids.

Case presentation

A 42-year-old male, chronic smoker presented with progressive dyspnea and productive cough of 1 year duration. He was evaluated and found to have multiple variable sized thin and thick-walled cysts with bizarre shapes in both lungs. A diagnosis of pulmonary Langerhans’ cell histiocytosis was made, and the patient was treated with smoking cessation and oral corticosteroids for 9 months.

Conclusion

Patients with characteristic clinical and radiological features can be diagnosed as pulmonary Langerhans’ cell histiocytosis, without a tissue biopsy. A good response may be seen with smoking cessation and oral corticosteroids in selected group of patients.

Langerhans cell histiocytosis in adolescent patients: a single-centre retrospective study

Background

Langerhans cell histiocytosis (LCH) is a myeloid dendritic cell disorder frequently affecting children more than adults. The presentation of LCH varies with age, however, the clinical characteristics and genetic profiles of adolescent LCH remain elusive. To address the knowledge gap, we performed a single-centre retrospective study of 36 adolescent LCH patients aged between 14 and 17 years at Peking Union Medical College Hospital.

Results

At the time of diagnosis, 10 patients were classified as unifocal single system LCH (27.8%), 2 patients had pulmonary single system LCH (5.6%), 5 patients had multifocal single system LCH with bone involvement (13.9%), and 19 patients had multisystem LCH (52.8%). The most prevalent involvement in multisystem patients was the pituitary gland (78.9%), followed by the bone (42.1%), lung (42.1%), and lymph nodes (42.1%). Eight (42.1%) patients had risk organ involvement. BRAF^N486_P490 was detected in 50% of patients who underwent next generation sequencing, and BRAF^V600E was detected in one patient. Chemotherapies were the first line treatment in 24 patients. One patient died and thirteen patients relapsed during the follow-up. The estimated 5-year OS rate and EFS rate were 94.7% and 59.0%, respectively.

Conclusions

In this study, we report a large series of adolescent LCH patients. The clinical characteristics of adolescent LCH patients may be close to adult LCH. Compared with pediatric cases, adolescent LCH tends to have more pituitary lesions and pulmonary involvement, fewer skin and hematopoietic involvement, a higher frequency of BRAF deletion mutation, and a lower frequency of BRAF^V600E mutation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02436-0.

Pulmonary Langerhans cell histiocytosis and multiple system involvement: A case report

BACKGROUND

Pulmonary Langerhans cell histiocytosis (PLCH) is a relatively rare type of lung disease, common in middle-aged smoking men. It is characterized by proliferation and infiltration of Langerhans cells, and the formation of multiple parabronchial mesenchymal nodules in lung tissue, and may lead to organ dysfunction. There are no typical symptoms and signs, and it is easily misdiagnosed or missed, and therefore deserves clinical attention and further discussion.

CASE SUMMARY

We describe the case of a nonsmoking 46-year-old man with PLCH diagnosed based on clinical manifestations of fever and dry cough, with a history of hypothyroidism and diabetes insipidus for 9 years. Computed tomography (CT)- and CT-guided puncture examinations revealed no abnormalities, and he ultimately underwent thoracoscopic biopsy to confirm the diagnosis. The pathological diagnosis was PLCH. Thyroid function was maintained by medication. Pituitary magnetic resonance imaging showed that the pituitary stalk had become thinner.

CONCLUSION

LCH often involves multiple systems. Moreover, the pathogenesis is not clear, clinical manifestations lack specificity, and diagnosis requires special attention. Diagnosis of PLCH can significantly benefit from comprehensive multidisciplinary analysis.

Is the combination of bilateral pulmonary nodules and mosaic attenuation on chest CT specific for DIPNECH?

Background

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is characterized by multifocal proliferation of pulmonary neuroendocrine cells. On chest CT, DIPNECH exhibits bilateral pulmonary nodules and mosaic attenuation in most patients. We sought to: (1) assess the specificity of this pattern (i.e., bilateral pulmonary nodules together with mosaic attenuation) for DIPNECH; (2) describe its differential diagnosis; and (3) identify the clinico-radiologic features that may help prioritize DIPNECH over other diagnostic considerations.

Methods

We searched the Mayo Clinic records from 2015 to 2019 for patients with bilateral pulmonary nodules and mosaic attenuation on CT who had a diagnostic lung biopsy. A thoracic radiologist reviewed all CT scans. Chi-square test was used for categorical variables, and odds ratios were utilized to measure the association between certain variables and DIPNECH.

Results

Fifty-one patients met our inclusion criteria; 40 (78%) were females and 34 (67%) were never-smokers. Median age was 65 (interquartile range 55–73) years. Lung biopsy was surgical in 21 patients (41%), transbronchial in 17 (33%), and transthoracic in 12 (24%); explanted lungs were examined in 1 (2%). Metastatic/multifocal cancer was the most common diagnosis, and was found in 17 (33%) cases. Bronchiolitis was diagnosed in 12 patients (24%), interstitial lung disease in 10 (20%), and DIPNECH in 5 (10%). Previous diagnosis of an obstructive lung disease (odds ratio 15.8; P = 0.002), and peribronchial nodular distribution on CT (odds ratio 14.4; P = 0.006) were significantly correlated with DIPNECH. Although statistical significance was not reached, DIPNECH nodules were more likely to display solid attenuations (80% vs. 67%, P = 0.45), and were more numerous; > 10 nodules were seen in 80% of DIPNECH cases vs. 52% in others (P = 0.23). Because DIPNECH primarily affects women, we analyzed the women-only cohort and found similar results.

Conclusions

Various disorders can manifest the CT pattern of bilateral pulmonary nodules together with mosaic attenuation, and this combination is nonspecific for DIPNECH, which was found in only 10% of our cohort. Previous diagnosis of an obstructive lung disease, and peribronchial distribution of the nodules on CT increased the likelihood of DIPNECH vs. other diagnoses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02103-w.

Recurrent pulmonary infections as the first presentation of Letterer Siwe disease

Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology that affects several organs. The fatal type of Langerhans cell histiocytosis is called Letterer Siwe disease (LSD) which is multisystem with a poor prognosis. Herein, we report a 20-month-old male who was admitted for recurrent pulmonary infections at the age of 10 months. Diagnostic workup revealed a Letterer-Siwe disease. The patient was treated with a good response.

A 35-Year-Old Smoker With Dyspnea and Chest Pain

CASE PRESENTATION

A 35-year-old veteran presented at our clinic with insidious dyspnea on exertion, nonspecific chest pain, and intermittent rash. The patient reported the development of dyspnea over 6 to 8 weeks. He had been physically active before this time but had since developed dyspnea after walking 30 to 61 m (100 to 200 ft) or with any more strenuous physical exertion. He described a nonproductive cough, with bilateral nonspecific chest pain that was worse with exertion. In addition, there was a fleeting, salmon-colored, nonpruritic rash over the bilateral arms and legs that was not responsive to over-the-counter topical steroids. The patient's medical history was notable for a 15-pack-year smoking history, posttraumatic stress disorder, depression, Clostridium difficile colitis, migraines, and alcohol abuse. Surgical history was notable for pyloric myotomy for stenosis and umbilical hernia repair. He lived with his partner and five children and was unemployed at the time because of dyspnea. There were no pets in the home and no prior occupational exposures, including silica, heavy metals, or birds.

Pulmonary Langerhans Cell Histiocytosis in a young Non-Smoking Female --Too many Rituals spoil the Lung

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare idiopathic cystic interstitial granulomatous lung disease seen almost exclusively in cigarette smokers. It typically occurs between 20-40 years of age and equally distributed among both sexes. Management includes smoking cessation, avoidance of second-hand smoke, and close follow-up. Corticosteroids may be required in those with symptomatic disease with worsening lung function despite smoking cessation and progressive nodular stage of the disease. Here, we report an interesting case of biopsy proven PLCH in a young never smoker female. Detailed questioning revealed significant exposure to incense smoke, highlighting a rare presentation of non-cigarette smoke related PLCH. Avoidance of incense smoke combined with oral prednisolone (0.5mg/kg) tapered over 6 months led to complete resolution of symptoms, disappearance of nodules in high resolution computed tomography (HRCT) of the thorax, and improvement in lung function. (www.actabiomedica.it)

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.

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

Update on Pulmonary Langerhans Cell Histiocytosis

Pulmonary Langerhans cell (LC) histiocytosis (PLCH) has unknown cause and is a rare neoplastic disorder characterized by the infiltration of lungs and various organs by bone marrow-derived Langerhans cells with an accompanying strong inflammatory response. These cells carry somatic mutations of BRAF gene and/or NRAS, KRAS, and MAP2K1 genes, which cause activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. PLCH occurs predominantly in young smokers, without gender predominance. Lungs might be involved as an isolated organ or as part of a multiorgan disease. High-resolution computed chest tomography plays an outstanding role in PLCH diagnosis. The typical radiological picture of PLCH is the presence of small intralobular nodules, “tree in bud” opacities, cavitated nodules, and thin- and thick-walled cysts, frequently confluent. Histological examination of the lesion and demonstration of characteristic eosinophilic granulomas with the presence of LCs that display antigen CD1a or CD207 in immunohistochemistry are required for definite diagnosis. Smoking cessation is the most important recommendation for PLCH patients, but treatment of progressive PLCH and multisystem disease is based on chemotherapy. Recently, new targeted therapies have been implemented.

Pulmonary Cystic Disease and Its Mimics

Cystic diseases of the lung encompass a fairly broad variety of different diseases with causes including genetic abnormalities, smoking-related problems, developmental disorders, malignant neoplasms, and inflammatory processes. In addition, there are several diagnoses that closely resemble cystic lung disease, including cavitary diseases, cystic bronchiectasis, emphysema, and cystic changes in fibrosing interstitial lung disease. This article provides a review of cystic lung disease and its gross and histologic mimics.

Clinical presentation and prognostic analysis of adult patients with Langerhans cell histiocytosis with pulmonary involvement

BACKGROUND

The study aimed to investigate the clinical features and prognosis factors of adult patients with Langerhans cell histiocytosis (LCH) with pulmonary involvement, especially multisystem (MS) LCH with pulmonary involvement.

METHODS

We retrospectively analyzed the demographic materials, clinical features and treatment outcomes of 119 adult LCH patients with pulmonary involvement at our center from January 1990 to November 2019.

RESULTS

Among 119 patients, 13 (10.9%) had single-system (SS) LCH, and 106 (89.1%) had MS-LCH with pulmonary involvement. SS-LCH patients had higher smoking rate (84.6% vs 52.8%, P = 0.026) and smoking index (300 vs 200, P = 0.019) than MS-LCH patients. The percentage of respiratory symptoms of SS-LCH patients was higher than MS-LCH patients (84.6% vs 53.8%, P = 0.034). Pulmonary function was impaired in 83.8% of the patients, and DLCO was the parameter most frequently impaired, accounting for 81.1%. The median DLCO was 65.1% predicted. Patients with pneumothorax had significantly worse DLCO (P = 0.022), FEV1 (P = 0.000) and FEV1/FVC (P = 0.000) than those without pneumothorax. During the follow-up, 72.4% of the patients had stable pulmonary function, and 13.8% showed improvements after chemotherapy. The estimated 3-year OS and EFS were 89.7 and 58.3%, respectively. Patients with a baseline FEV1 ≤ 55% predicted had worse OS. A history of pneumothorax indicated worse EFS and cytarabine based therapy predicted better EFS.

CONCLUSIONS

An FEV1 ≤ 55% predicted and a history of pneumothorax at diagnosis indicated a poor prognosis. Cytarabine based regimen may arrest the decline in pulmonary function in LCH patients with pulmonary involvement and improve EFS.

Laryngeal Langerhans Cell Histiocytosis: A Case Report and Literature Review

OBJECTIVE

To describe a case of laryngeal Langerhans cell histiocytosis, discuss its characteristic features and management, and provide a review of the available literature.

METHODS

A patient presenting to a tertiary care medical center with dyspnea and hoarseness is described. A literature review of laryngeal Langerhans cell histiocytosis cases was performed through a search of articles indexed in the National Institutes of Health PubMed system.

RESULTS

We report a case of a 69-year old male, who presented with a laryngeal mass highly suspicious for laryngeal squamous cell carcinoma, was treated with laser excision, and was subsequently found to have laryngeal Langerhans cell histiocytosis upon histological analysis. Including our current case, we found six prior reported cases of laryngeal Langerhans cell histiocytosis in the literature. Of the six cases, four were in adults, while two were in children. Dyspnea is a common presenting complaint present in all cases. Smoking may be a potential risk factor.

CONCLUSIONS

Laryngeal Langerhans cell histiocytosis is a rare condition and an important consideration in the differential diagnosis of patients presenting with a laryngeal mass and symptoms of dyspnea or hoarseness. Biopsy and histopathological analysis are key to the diagnosis. Surgical excision and radiotherapy are successful treatments used in clinical practice.

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.

Multisystemic Pediatric Langerhans cell histiocytosis: a comprehensive clinico-pathological and BRAF V600E mutation study at autopsy

Langerhans cell histiocytosis (LCH), a disorder of antigen-presenting cells, is the commonest disorder of the mononuclear phagocytic system. Diagnosis is always challenging due to heterogeneous clinical presentation. However, with the evolution and better understanding of its biology, many of these children are being diagnosed early and offered appropriate therapy. Despite these advances, in developing countries, an early diagnosis is still challenging due to resource constraints for specialized tests. As a result, many patients succumb to their disease. Autopsy data on LCH is notably lacking in the literature. We sought to analyze the clinical (including mutational) and morphologic features at autopsy in six proven cases of LCH. This study includes a detailed clinico-pathological and mutational analysis of 6 proven cases of LCH. Presence of BRAF V600E mutation was assessed by both Real Time PCR and Sanger sequencing. A varied spectrum of organ involvement was noted with some rare and novel morphological findings, like nodular bronchiolocentric infiltration of LCH cells, lymphovascular emboli of LCH cells, and paucity of eosinophils within the infiltrate; these features have not been described earlier. Surprisingly, all cases were negative for BRAF V600E mutation on both RQ-PCR and Sanger sequencing. The present study is perhaps the first autopsy series on LCH. This extensive autopsy analysis represents a correlation of pathological features with clinical symptoms which provides clues for a timely diagnosis and appropriate therapeutic intervention. Also, our findings hint at the low frequency of BRAF V600E mutation in our LCH patients.

Recurrent pneumothorax, skin lesions and frequent urination

A 25-year-old male is admitted with complaints of dry cough for the past 5 years, and increased thirst, urinary frequency and output for the past 18 months. He also complains of shortness of breath on climbing a flight of stairs, and itchy lesions on the scalp and back for the past 2–3 months. There is no history of bone pain or abdominal pain. He has history of bilateral recurrent pneumothoraxes, twice on the right and once on the left side, in the past month. Pleurodesis with povidone iodine is performed on left side and the patient is transferred to your hospital with persistent right pneumothorax with air leak, with an intercostal drainage tube in situ. The patient is a never-smoker with no family history of pneumothorax. On general examination, he has small papules, 1–2 mm in diameter, with scaling over scalp and back. Onycholysis, onychoschisis and subungual splinter haemorrhages are present (figure 1).

The causes of cystic lung diseases are varied. Proper evaluation is required for appropriate management.http://bit.ly/37J7dvE

MAPK mutations and cigarette smoke promote the pathogenesis of pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare smoking-related lung disease characterized by dendritic cell (DC) accumulation, bronchiolocentric nodule formation, and cystic lung remodeling. Approximately 50% of patients with PLCH harbor somatic BRAF-V600E mutations in cells of the myeloid/monocyte lineage. However, the rarity of the disease and lack of animal models have impeded the study of PLCH pathogenesis. Here, we establish a cigarette smoke-exposed (CS-exposed) BRAF-V600E-mutant mouse model that recapitulates many hallmark characteristics of PLCH. We show that CD11c-targeted expression of BRAF-V600E increases DC responsiveness to stimuli, including the chemokine CCL20, and that mutant cell accumulation in the lungs of CS-exposed mice is due to both increased cellular viability and enhanced recruitment. Moreover, we report that the chemokine CCL7 is secreted from DCs and human peripheral blood monocytes in a BRAF-V600E-dependent manner, suggesting a possible mechanism for recruitment of cells known to dominate PLCH lesions. Inflammatory lesions and airspace dilation in BRAF-V600E mice in response to CS are attenuated by transitioning animals to filtered air and treatment with a BRAF-V600E inhibitor, PLX4720. Collectively, this model provides mechanistic insights into the role of myelomonocytic cells and the BRAF-V600E mutation and CS exposure in PLCH pathogenesis and provides a platform to develop biomarkers and therapeutic targets.

Spontaneous pneumothorax and air travel in Pulmonary Langerhans cell histiocytosis: A patient survey

BACKGROUND

The optimal approach for management of spontaneous pneumothoraces (SPs) and the safety of air travel in patients with pulmonary Langerhans cell histiocytosis (PLCH) are not well established.

METHODS

Patients with PLCH were recruited from the Rare Lung Diseases Clinic Network and the Histiocytosis Association, and surveyed about disease manifestations and safety of air travel.

RESULTS

A total of 94 patients completed the survey. Median age at diagnosis of PLCH was 40 years (range: 15-67 years). Average interval between symptom onset and diagnosis was 2.9 years (range: -4 to 31 years). Twenty-two patients (23%) had at least one SP, of which 14 (64%) had at least one additional SP that showed either an ipsilateral recurrence (10 patients; 45%) or a contralateral recurrence (8 patients; 36%). Mean age at the time of first SP was 29 years. SP was the presenting manifestation that led to the diagnosis of PLCH in 19% of patients, typically after the second episode. Surgical pleurodesis reduced the recurrence rate of SP by half in comparison with conservative management (29% vs. 65%, p = 0.025). Two patients experienced an episode of SP during air travel, consistent with an air travel-related pneumothorax rate of 2.4% per patient and 0.27% per flight.

CONCLUSIONS

SP is a common manifestation of PLCH, can be seen in approximately one-fourth of the patients, and has a high recurrence risk. Surgical pleurodesis leads to a substantial reduction in the SP recurrence risk. The risk of an air travel-related SP in patients with PLCH is about 2-3 per thousand flights. TRIAL REGISTRY CLINICALTRIALS.GOV: NCT03052101.

Bilateral Pulmonary Langerhans's Cell Histiocytosis is Surgical Challenge in Children: A Case Report

Background  Pulmonary Langerhans's cell histiocytosis (PLCH) is a rare cause of interstitial lung disease in children and more than half of the cases are bilateral. Persistent respiratory distress due to spontaneous pneumothorax (SP) in bilateral PLCH may refractory to conservative treatment and posed a great challenge to surgical modalities. A 3-year-old boy with SP due to bilateral PLCH is presented to discuss the surgical options of recurrent and refractory PLCH cases in children.

Case Report  The patient was admitted to the emergency department with severe respiratory distress and SP. After chest tube insertion, biopsy from neck mass revealed Langerhans's cell histiocytosis. Chemotherapy including vinblastine and prednisone was initiated. Due to persistent respiratory difficulty and air leaks, talc pleurodesis and thoracoscopic bullae excision with pleural decortication were performed. Two months after the admission, due to nosocomial infection and severe respiratory distress, extracorporeal membranous oxygenation (ECMO) support was initiated. The patient was died of ECMO complications on 24th day of ECMO.

Conclusion  Despite the use of chemotherapy and surgical excision of cystic lesions, bilateral PLCH in children may have lethal outcome. Other treatment options including respiratory support with ECMO and lung transplantation should be considered as last resort of treatment alternative in persistent cases.

Clinical Research of Pulmonary Langerhans Cell Histiocytosis in Children

Background:

Pulmonary Langerhans cell histiocytosis (PLCH) is an interstitial primary pulmonary disease, characterized by Langerhans cell proliferation. It is easily misdiagnosed in children. This study aimed to characterize the clinical manifestations and features of PLCH by retrospective analysis.

Methods:

A retrospective analysis was performed in 117 PLCH patients out of 338 LCH patients who were admitted in our center from November 2006 to October 2013. Variables between two groups were compared by Mann-Whitney U-test and Chi-square test. Kaplan-Meier curves were constructed to compare the survival rates and Cox regression to evaluate the effect of risk factors.

Results:

The median age of PLCH group was significantly lower than that of non-PLCH group (18.63 months vs. 43.4 months, P < 0.001). All PLCH children had other organ involvement and only 11 cases (9.4%) had respiratory symptoms. The most common radiologic finding was cystic lesions (29 cases, 24.8%). Pulmonary function abnormalities were dominated by obstructive ventilatory dysfunction (63 cases, 82.9%). The 5-year overall survival (OS) of PLCH children was 93.6% ± 2.3% and the event-free survival (EFS) was 55.7% ± 5.2%. Among the 38 cases with progressed or relapsed disease, five cases (13.2%) were due to progression or recurrence of lung damage. The 5-year OS of PLCH children with “risk organ” involvement was significantly lower than those without “risk organ” involvement (86.0% ± 4.9% vs. 100%, χ² = 8.793, P = 0.003). The difference of EFS between two groups was also significant (43.7% ± 7.7% vs. 66.3% ± 6.5%, χ² = 5.399, P = 0.020). The “risk organ” involvement had a significant impact on survival (hazard ratio = 1.9, P = 0.039).

Conclusions:

PLCH mainly occurs in young children, and only a small percentage of patients have respiratory symptoms. They generally have other organ involvement. Most of PLCH children have a good prognosis and most lung lesions could have improved or stabilized. Management of “risk organ” involvement is the key point to improving EFS.

Electrical impedance tomography effectively used in a case of paediatric pulmonary Langerhans cell histiocytosis

A 2-year-old boy with severe pulmonary Langerhans cell histiocytosis presented in extreme respiratory failure. He was intubated and ventilated. Despite maximal support, he deteriorated and needed extremely high ventilator pressures. An electrical impedance tomography monitor was used to inform management. This is a monitoring technique which is not used in children due to the lack of suitable interface devices and a lack of randomised clinical evidence. Despite technical difficulties, a good signal was achieved. This informed management and enabled the selection of a suitable ventilator strategy, facilitating weaning. Electrical impedance tomography is a viable technology for use in paediatric critical respiratory failure. This is a non-invasive and safe technology which adds individual patient information which is not available through any other modalities. We urge equipment manufacturers to develop belts which will allow routine application of this life-saving technology in children.

Simultaneous Bilateral Spontaneous Pneumothorax in an Adult Patient With Pulmonary Langerhans Cell Histiocytosis: A Case Report

We report a case of a young female with known history of pulmonary Langerhans cell histiocytosis who was initially presented in the emergency department of a university hospital with respiratory distress. Clinical assessment and diagnostic workup revealed left hemithorax subcutaneous emphysema, bilateral pneumothorax, and atelectasis in both lower lung lobes. The patient was treated with bilateral staged thoracoscopic bullectomy and mechanical abrasion of the parietal pleura combined with chemical pleurodesis with talc. A new occurrence of right-sided pneumothorax was noticed 3 days after surgery, which was treated with chest tube insertion and chemical pleurodesis. The aforementioned surgical approach resulted in complete lung expansion and the patient’s full recovery. A review of pulmonary Langerhans cell histiocytosis and treatment options in cases of pneumothorax due to lung histiocytosis is also presented in this report.

Oral manifestation of Langerhans cell histiocytosis: a case report

Background

Bone necrosis of the jaw is a serious condition with a broad differential diagnosis of pathologies such as cutaneous histiocytosis, bone metastases or malignant tumours. In addition to the most common cause, medication related osteonecrosis of the jaw (MRONJ), one must consider a number of other causes, such as histiocytosis.

Langerhans cell histiocytosis (LCH) is a histiocytic disorder with a large spectrum of clinical manifestations and with possible involvement of a variety of organs. This case shows the importance of an early detection of this rare disease in order to prevent further spreading. Even if an initial diagnosis in the oral cavity is rare, dentists should be aware of this disease.

Case presentation

The presented case describes a patient who was referred for evaluation and treatment due to exposed bone and extensive osteolysis in the region of the upper and lower jaw. After biopsy and diagnosis of LCH, the patient was treated with systemic therapy, achieved remission and is disease free after a 2 year of follow up.

Conclusions

This case report illustrates that when dealing with unclear osteolytic changes of the jawbone, Langerhans cell histiocytosis must be taken into consideration in the differential diagnosis and biopsy must be performed in case of suspicion.

[The respiratory effects of smoking]

A marked increase in the morbidity and mortality of a large number of broncho-pulmonary diseases has been documented in relation to smoking. The influence of tobacco smoking on various respiratory conditions. is discussed: incidence, severity or natural history modification of some respiratory illnesses: obstructive lung diseases (COPD, asthma), lung cancer, bacterial, viral respiratory infections, with the impact of smoking on tuberculosis. Finally, the relationship of tobacco with diffuse interstitial lung disease: protective role of smoking (controversial in sarcoidosis, real in hypersensitivity pneumonitis). The benefits of smoking cessation are described.

Langerhans cell histiocytosis in children - a disease with many faces. Recent advances in pathogenesis, diagnostic examinations and treatment

Langerhans cell histiocytosis is a rare clonal disease characterized by the proliferation of CD1a-positive immature dendritic cells. The purpose of this article was to present an updated review of recent advances in the pathogenesis, clinical features, imaging and treatment of this disease. The discovery of oncogenic BRAF mutations and the presence of proinflammatory cytokines and chemokines confirmed the unusual characteristics of this disease. Currently, children with organ involvement who do not have a good response to chemotherapy and have neurodegeneration or diabetes insipidus are the most problematic patients. Further research is needed to improve the results of treatment.

Pulmonary Langerhans cell histiocytosis, acute myeloid leukemia, and myelofibrosis in a large family and review of the literature

BACKGROUND

There is mounting evidence that Langerhans cell histiocytosis (LCH) and acute myeloid leukemia (AML) are hematopoietic neoplasms that arise from the same myeloid precursor cell. In addition, studies suggest a relationship between LCH and primary idiopathic myelofibrosis (MF). Furthermore familial LCH, AML, and MF have each been reported.

METHODS

We examined more than 750 pedigrees of familial hematologic malignancies for evidence of familial LCH, AML, and/or MF and identified one family with all three neoplasms, which is presented here.

FINDINGS

In four generations of this large family there are five cases of AML in three generations, two cases of LCH in two generations and three cases of MF in two generations. Anticipation of -18 and -6 years was present in the patients with MF, and -8 years in the patients with LCH. Anticipation was also identified between one AML patient pair in generations III and IV (-18 years) and three patients with AML in generations II, III, and IV (-5 years and -10 years).

INTERPRETATION

This is the first report of familial LCH, AML, and MF in one family. The pedigree suggests a common basis for these entities, which is further suggested by the presence of anticipation in the pedigree.

Spontaneous pneumothorax in diffuse cystic lung diseases

PURPOSE OF REVIEW

Diffuse cystic lung diseases (DCLDs) are a heterogeneous group of disorders with varying pathophysiologic mechanisms that are characterized by the presence of air-filled lung cysts. These cysts are prone to rupture, leading to the development of recurrent spontaneous pneumothoraces. In this article, we review the epidemiology, clinical features, and management DCLD-associated spontaneous pneumothorax, with a focus on lymphangioleiomyomatosis, Birt-Hogg-Dubé syndrome, and pulmonary Langerhans cell histiocytosis.

RECENT FINDINGS

DCLDs are responsible for approximately 10% of apparent primary spontaneous pneumothoraces. Computed tomography screening for DCLDs (Birt-Hogg-Dubé syndrome, lymphangioleiomyomatosis, and pulmonary Langerhans cell histiocytosis) following the first spontaneous pneumothorax has recently been shown to be cost-effective and can help facilitate early diagnosis of the underlying disorders. Patients with DCLD-associated spontaneous pneumothorax have a very high rate of recurrence, and thus pleurodesis should be considered following the first episode of spontaneous pneumothorax in these patients, rather than waiting for a recurrent episode. Prior pleurodesis is not a contraindication to future lung transplant.

SUMMARY

Although DCLDs are uncommon, spontaneous pneumothorax is often the sentinel event that provides an opportunity for diagnosis. By understanding the burden and implications of pneumothoraces in DCLDs, clinicians can facilitate early diagnosis and appropriate management of the underlying disorders.

Autopsy Findings in A Case of Pulmonary Langerhans Cell Histiocytosis-Associated Pulmonary Hypertension

Patient: Female, 35

Final Diagnosis: Pulmonary Langerhans cell histiocytosis associated with secondary pulmonary hypertension

Symptoms: Dyspnea

Medication: —

Clinical Procedure: Oxygen • sildenafil • bosentan • prostanoids

Specialty: Pulmonology

A 26-year-old man with dyspnea and chest pain

A 26-year-old smoker male presented with a history of sudden onset dyspnea and right-sided chest pain. Chest radiograph revealed large right-sided pneumothorax which was managed with tube thoracostomy. High-resolution computed tomography thorax revealed multiple lung cysts, and for a definite diagnosis, a video-assisted thoracoscopic surgery-guided lung biopsy was performed followed by pleurodesis. This clinicopathologic conference discusses the clinical and radiological differential diagnoses, utility of lung biopsy, and management options for patients with such a clinical presentation.

Dendritic Cell Trafficking and Function in Rare Lung Diseases

Dendritic cells (DCs) are highly specialized immune cells that capture antigens and then migrate to lymphoid tissue and present antigen to T cells. This critical function of DCs is well defined, and recent studies further demonstrate that DCs are also key regulators of several innate immune responses. Studies focused on the roles of DCs in the pathogenesis of common lung diseases, such as asthma, infection, and cancer, have traditionally driven our mechanistic understanding of pulmonary DC biology. The emerging development of novel DC reagents, techniques, and genetically modified animal models has provided abundant data revealing distinct populations of DCs in the lung, and allow us to examine mechanisms of DC development, migration, and function in pulmonary disease with unprecedented detail. This enhanced understanding of DCs permits the examination of the potential role of DCs in diseases with known or suspected immunological underpinnings. Recent advances in the study of rare lung diseases, including pulmonary Langerhans cell histiocytosis, sarcoidosis, hypersensitivity pneumonitis, and pulmonary fibrosis, reveal expanding potential pathogenic roles for DCs. Here, we provide a review of DC development, trafficking, and effector functions in the lung, and discuss how alterations in these DC pathways contribute to the pathogenesis of rare lung diseases.

How I manage pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare sporadic cystic lung disease of unknown aetiology that is characterised by the infiltration and destruction of the wall of distal bronchioles by CD1a⁺ Langerhans-like cells. In adults, PLCH is frequently isolated and affects young smokers of both sexes. Recent multicentre studies have led to the more standardised management of patients in clinical practice. Smoking cessation is essential and is occasionally the only suitable intervention. Serial lung function testing is important because a significant proportion of patients may experience an early decline in forced expiratory volume in 1 s and develop airflow obstruction. Cladribine was reported to dramatically improve progressive PLCH in some patients. Its efficacy and tolerance are currently being evaluated. Patients who complain of unexplained dyspnoea with decreased diffusing capacity of the lung for carbon monoxide should be screened for pulmonary hypertension by Doppler echocardiography, which must be confirmed by right heart catheterisation. Lung transplantation is a therapeutic option for patients with advanced PLCH.The identification of the BRAF^V600E mutation in approximately half of Langerhans cell histiocytosis lesions, including PLCH, and other mutations of the mitogen-activated protein kinase (MAPK) pathway in a subset of lesions has led to targeted treatments (BRAF and MEK (MAPK kinase) inhibitors). These treatments need to be rigorously evaluated because of their potentially severe side-effects.

Differential diagnosis of granulomatous lung disease: clues and pitfalls

Granulomatous lung diseases are a heterogeneous group of disorders that have a wide spectrum of pathologies with variable clinical manifestations and outcomes. Precise clinical evaluation, laboratory testing, pulmonary function testing, radiological imaging including high-resolution computed tomography and often histopathological assessment contribute to make a confident diagnosis of granulomatous lung diseases. Differential diagnosis is challenging, and includes both infectious (mycobacteria and fungi) and noninfectious lung diseases (sarcoidosis, necrotising sarcoid granulomatosis, hypersensitivity pneumonitis, hot tub lung, berylliosis, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, rheumatoid nodules, talc granulomatosis, Langerhans cell histiocytosis and bronchocentric granulomatosis). Bronchoalveolar lavage, endobronchial ultrasound-guided transbronchial needle aspiration, transbronchial cryobiopsy, positron emission tomography and genetic evaluation are potential candidates to improve the diagnostic accuracy for granulomatous lung diseases. As granuloma alone is a nonspecific histopathological finding, the multidisciplinary approach is important for a confident diagnosis.

A multidisciplinary approach is crucial for the accurate differential diagnosis of granulomatous lung diseaseshttp://ow.ly/FxsP30cebtf

A rare 'incidentaloma' found on low-dose CT screening for lung cancer: 'scanner beware'

Screening for lung cancer with low-dose computed tomography (LDCT) has been shown to reduce mortality and has been recommended by the U.S. Preventive Services Task Force for adults 55 to 80 years of age with a 30 pack-year smoking history who are either current smokers or those that quit within 15 years. However, the overwhelming majority of abnormalities detected are not from malignancy. We report a case of pulmonary Langerhans' cell histiocytosis, here-to-fore thought of as extremely uncommon, and make readers aware that this may be increasingly found as LDCT is more widely adopted.

Vinblastine chemotherapy in adult patients with langerhans cell histiocytosis: a multicenter retrospective study

Background

Vinblastine is the standard treatment for children with Langerhans cell histiocytosis (LCH). Whether this treatment could be extended to adults with LCH is questionable. This retrospective multicenter study included 35 adult patients (median age 33 years; 23 men; 80% with multisystem LCH) who were treated with vinblastine + steroids as a first-line chemotherapy and followed for a median time of 83 months. The objectives were to determine the overall response rate (based on the Histiocyte Society criteria), disease reactivation rate, toxicity, permanent consequences, and survival rate corresponding to this treatment. The lung involvement outcome was based on serial lung function tests. The distribution of right-censored end points was estimated by the Kaplan-Meier method. Univariate Cox model with time-fixed and time-varying covariates was used for the predictive analysis of reactivation in the responders. Univariate analyses of risk factors for neurotoxicity were based on nonparametric Wilcoxon rank sum tests and exact Fisher tests.

Results

The median duration of the first course of vinblastine was 7.6 months, with a median cumulative dose of 160 mg [IQR 120–212]. Seventy percent of the patients were responders at the end of this treatment. Subsequently, LCH reactivation occurred with a 5-year cumulative incidence of 40%. During the study, 27 reactivations were observed in 17 patients, and half of these episodes were retreated with vinblastine. At the end of the last vinblastine treatment, 70% of the patients were responders. None of the patients with impaired lung function improved. No grade 3–4 peripheral neuropathy was observed. At the final vinblastine treatment, permanent LCH consequences, primarily pituitary stalk involvement, were present in 15 (43%) patients, and all were present at the time of vinblastine initiation. The 10-year survival rate was 86.2% (95CI, 71.8–100%), and the 2 patients who died from LCH had risk organ localizations.

Conclusions

Vinblastine is an effective and well-tolerated first-line treatment for adult LCH except in patients with lung involvement and impaired lung function. However, a significant portion of patients experienced LCH reactivation during long-term follow up. As in childhood LCH, the presence of risk organ involvement has a negative impact on patient prognosis.

Langerhans cell histiocytosis: Skin diseases and visceral lesions

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

Langerhans Cell Histiocytosis and Langerhans Cell Sarcoma: Current Understanding and Differential Diagnosis

Langerhans cell (LC) histiocytosis (LCH) and LC sarcoma (LCS) are proliferative processes consisting of cells having morphologic and phenotypic features of Langerhans cells (LCs), although the latter may have lost some of these features. Because neoplastic nature of LCH as well as LCS is more likely by recent studies, a category of LC hyperplasia can be better characterized. LCH and LCS are rarely seen in daily pathology practice, but it is important to accurately characterize these lesions. For this purpose, an outline covering proliferations of LC and related cells was constructed. The scheme of this outline is based especially on evaluating borderline lesions, neoplastic trans-differentiation, and degree of similarity with the normal counter-parts. In addition, the organization and update of the current classification scheme for histiocytic and dendritic-cell proliferations is presented.

Diagnosis and treatment of cystic lung disease

Cystic lung disease (CLD) is a group of lung disorders characterized by the presence of multiple cysts, defined as air-filled lucencies or low-attenuating areas, bordered by a thin wall (usually < 2 mm). The recognition of CLDs has increased with the widespread use of computed tomography. This article addresses the mechanisms of cyst formation and the diagnostic approaches to CLDs. A number of assessment methods that can be used to confirm CLDs are discussed, including high-resolution computed tomography, pathologic approaches, and genetic/ serologic markers, together with treatment modalities, including new therapeutic drugs currently being evaluated. The CLDs covered by this review are lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, Birt-Hogg-Dube syndrome, lymphocytic interstitial pneumonia/follicular bronchiolitis, and amyloidosis.

Molecular analysis of BRAF V600E mutation in multiple nodules of pulmonary Langerhans cell histiocytosis

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, smoking-related histiocytic disorder with variable clinical symptoms. Like in other non-pulmonary Langerhans cell proliferations, PLCH has recently been shown to harbour BRAF V600E mutations in a significant subset of cases, thus challenging the concept of PLCH being a reactive disorder. Here, we analysed 38 formalin-fixed and paraffin-embedded PLCH nodules of nine patients for BRAF mutation using two different molecular methods. Using pyrosequencing and allele-specific quantitative PCR (AS-PCR), BRAF V600E mutations were found in 16/38 (42%) and 31/37 (84%) nodules, respectively. Analysing different nodules of the same patients with pyrosequencing 3/6 patients showed a concordant BRAF mutation status. When allele-specific quantitative PCR was used, condordant results were found in 5/6 patients. Our findings clearly indicate that (a) the sensitivity of the method used is crucial in analysing BRAF mutation status, (b) AS-PCR is more sensitive in detecting BRAF V600E mutations than pyrosequencing,

Lung ultrasound has limited diagnostic value in rare cystic lung diseases: a cross-sectional study

Background: Lung ultrasound (LUS) used to identify interstitial syndrome (IS) and pleural thickening related to diffuse parenchymal lung disease (DPLD) has shown significant correlations with ground glass opacity (GGO) on high-resolution computed tomography (HRCT). However, the applicability of LUS in patients with DPLD subtypes as rare cystic lung diseases has not previously been investigated. This study aimed to observe if distinctive LUS findings could be found in patients with lymphangioleiomyomatosis (LAM), pulmonary Langerhans cell histiocytosis (PLCH), and Birt-Hogg-Dubé syndrome (BHDS). Methods: This single centre case-based cross-sectional study of patients diagnosed with LAM, PCLH and BHDS was conducted at a Danish DPLD specialist centre. Patients underwent clinical examination including LUS. LUS findings were compared to findings scored according to a modified Belmaati score on HRCT and reviewed in consensus between two pulmonologists and one radiologist. Results: Twelve patients with HRCT proven cystic lung disease were included, six with LAM, three with PLCH, two with BHDS, and one with uncharacteristic cystic lung disease. The mean age was 48.7 years (SD ± 15.8). In general all had normal LUS findings. IS could not be found in any patients despite GGO presentation on HRCT among 75% of the patients with a Belmaati in the highest category of 0.76-1.00. Pleural thickening on LUS was present in three patients, but with inconsistent findings. Conclusion: This study indicates that LUS has limited value as a diagnostic tool in patients with LAM, PLCH, and BHDS as normal LUS findings did not rule out severe cystic lung disease.

Bone Langerhans cell histiocytosis with pulmonary involvement in an adult non-smoker: A case report and brief review of the literature

Langerhans cell histiocytosis (LCH) is a rare disease of unknown cause, which encompasses a set of disorders of multiple organs with various clinical presentations that share the common characteristic of sizeable Langerhans cell infiltration. The clinical spectrum of LCH ranges from solitary bone lesions to involvement of other organs. lung involvement in LCH may be part of a multisystem disease, which almost exclusively occurs in adult smokers, while it is overlooked or misdiagnosed in the majority of non-smokers. High-resolution computed tomography (HRCT) of the chest is crucial for diagnosis; however, the treatment and prognosis of this disease have not been clearly determined. We herein present the case of a non-smoking adult patient who presented with lower limb pain and was diagnosed via biopsy with lch with multisystem involvement, including the bone and lungs. Lytic lesions in the corpus of the sacroiliac joint, sacrum, acetabulum and femoral head by a soft tissue mass were observed on diagnostic CT. In addition, chest HRCT revealed multiple cysts in the bilateral lungs, predominantly in the upper lobes. The final diagnosis of LCH was confirmed by histopathological examination and immunohistochemical staining for CD1a and S-100. Corticosteroid treatment alleviated lower limb pain and improved the patient's quality of life; thus, corticosteroids may be considered as a potential treatment option for patients with LCH.