Pulmonary Langerhans cell histiocytosis in adults: high-resolution CT-pathology comparisons and evolutional changes at CT

High resolution chest computed tomography responses for a cohort of adult with pulmonary Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a heterogeneous histiocytosis with various pulmonary manifestations and imaging. We aim to evaluate the pulmonary response of LCH by high resolution chest computed tomography (HRCT) through continuous follow-up.We conducted a retrospective analysis of 73 adult LCH patients with pulmonary involvement. HRCT response was assessed by the change of HRCT global score (nodule score plus cyst score) between the baseline and after therapy. Among them, 69 patients (94.5%) had multi-system LCH with pulmonary involvement. 42 patients received methotrexate and cytarabine regimen, 15 received cytarabine monotherapy, 7 underwent target therapy. 14 (19.2%) achieved complete response (CR) and 45 (61.6%) achieved partial response (PR). The mean global lung-lesion score decreased from 12.2 to 10.6. The mean nodule score decreased from 4.7 to 4.1 and the mean cyst score decreased from 7.4 to 6.5. Overall, 25 (34.2%) exhibited an HRCT response and 3 (4.1%) had HRCT progression, while 45 (61.6%) maintained the same. Among patients with CR or PR, 57.1% and 40.5%, respectively, experienced an HRCT response, whereas no patient with SD or PD had an HRCT response. Multivariable analyses revealed that patients who received low dose cytarabine regimen and those with HRCT score ≥ 10 predicted a shorter PFS. Long Chang, Luo Wang, and Zheng-zheng Liu contributed equally to this work.

A Case of Nonsmoker Pulmonary Langerhans Cell Histiocytosis With Multiple Pulmonary Nodules Disappeared and Appeared

We present a non-smoker woman in her 40s with PLCH who presented with atypical imaging findings of multiple pulmonary noncavitary nodules without air cysts with repeated waxing and waning.

[Differential diagnosis of cystic and nodular lung diseases]

BACKGROUND

Cystic and nodular lung diseases encompass a broad spectrum of diseases with different etiologies and clinicoradiological presentations. Their differentiation is crucial for patient management but can be complex due to diseases with features of both categories and overlapping radiological patterns.

OBJECTIVE

This study aims to describe the imaging features of cystic and nodular lung diseases in high-resolution computed tomography (CT) in detail-primarily based on their etiology-in order to allow a more accurate differential diagnosis of these diseases.

MATERIALS AND METHODS

A narrative review based on current literature on the topic was conducted from a clinicoradiological perspective.

RESULTS

This paper systematically categorizes the differential diagnosis of cystic and nodular lung disease and provides insights into their radiological patterns and etiologies. It highlights the role of CT in the diagnosis of these diseases and emphasizes the importance of multidisciplinary panels combining expertise from radiology, pulmonology, rheumatology, and pathology.

CONCLUSION

Reliable differential diagnosis of cystic and nodular lung diseases, particularly based on their radiological features alone, remains difficult due to their overlapping and dynamic nature. Multidisciplinary boards should be the clinical standard for accurate work-up of these diseases, as they combine the medical history, symptoms, radiological findings, and, if necessary, histopathological examinations, thus providing a more robust framework for diagnosis and management.

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.

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

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

Multisystem Langerhans cell histiocytosis: Literature review and case report

Langerhans cell histiocytosis (LCH) refers to a group of diseases of unknown etiology, typically discovered in childhood, characterized by the accumulation of Langerhans cells (white blood cells with large cell nuclei that may contain cytoplasmic histiocytosis X bodies) involving one or more organ systems, including bones, lungs, pituitary gland, skin, lymph nodes, and liver. This disease is also known as histiocytosis X or eosinophilic granuloma. Pulmonary LCH is common (identified in 40% of LCH patients) and may be isolated to the lung or involve other organs. Although LCH is characterized by clonal cell proliferation, adult LCH is considered likely to represent the manifestation of an aberrant immune response to an unspecified antigenic stimulus rather than a manifestation of tumor proliferation. We report a very complicated clinical case of LCH, with multiple organ damage that received a variety of different diagnoses. An LCH diagnosis was confirmed based on postoperative spinal cord pathology results and immunohistochemistry examinations. This case report highlights the clinical, laboratory, and imaging signs observed in this case that should be noted to help doctors more quickly recognize, diagnose, and treat similar cases.

Pulmonary manifestations of Erdheim-Chester disease: clinical characteristics, outcomes and comparison with Langerhans cell histiocytosis

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis that typically affects many organs, including the lung and pleura. However, there are few studies concerning pulmonary involvement in ECD patients, as well as the difference of pulmonary involvement between ECD and Langerhans cell histiocytosis (LCH). We performed a retrospective study of 54 ECD patients, and compared the pulmonary manifestations with those of adult LCH patients in our centre. The median age of diagnosis of the 54 ECD patients was 48 years (range 9-66 years). Chest computed tomography (CT) scans revealed lung involvement in 49 (91%) patients and pleural involvement in 34 (63%). Thirty-three (61%) patients had interstitial lung disease (ILD) with varying degrees of interlobular septal thickening, micronodules, and ground-glass opacities. ECD and LCH patients with pulmonary involvement showed significant differences in smoking status (P < 0·001), respiratory symptoms (P = 0·001) such as cough and pneumothorax (P < 0·001), and radiological findings, including cysts (P < 0·001), opacities (P < 0·001), and pleural thickening (P < 0·001). With a median follow-up duration of 24 months (range, 1-84 months), the estimated three-year overall survival (OS) of this entire ECD cohort was 90·2%. Patients with ILD tended to have worse progression-free survival (PFS) than those with no ILD (P = 0·29).

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 nodular and cystic light chain deposition disease: A retrospective review of 10 cases

INTRODUCTION

Light chain deposition disease (LCDD) rarely involves the lungs. We report clinical and radiologic findings of pulmonary LCDD.

METHODS

We retrospectively identified patients with biopsy-proven pulmonary LCDD seen at Mayo Clinic (Rochester, Minnesota) from January 1997 through December 2018. Demographic, clinical, and imaging features were analyzed.

RESULTS

We identified 10 patients with pulmonary LCDD (median age at diagnosis, 55 years; range, 39-77 years). Eight patients were women and 7 were never-smokers. Dyspnea (n = 3) and chest pain (n = 3) were the most common respiratory symptoms. Associated conditions included Sjögren syndrome (n = 6), sarcoidosis (n = 1), and limited scleroderma (n = 1). Eight patients had mucosa-associated lymphoid tissue (MALT) lymphoma. Among the 9 patients with chest computed tomography (CT) images, 8 (89%) had cysts. Cysts were predominantly distributed in the lower lung and were round or oval. All patients had multiple cysts (5 patients had 1-5 cysts, 3 had >20 cysts). The median diameter of the largest cyst was 18 mm (range, 5-68 mm). All 9 patients had solid nodules (3 had >10 nodules). Five patients had subsolid nodules. The median diameter of the largest solid nodules was 13 mm (range, 6-26 mm). Positron emission tomography-CT images were available for 8 patients. The median maximum standardized uptake value of the most avid pulmonary nodule was 2.2 (range, 1.9-6.0). Two patients died during a median follow-up of 2.3 years (range, 0.5-9.9 years).

CONCLUSIONS

Pulmonary LCDD is characterized by cysts and nodules. The disease is associated with MALT lymphoma, especially in the setting of Sjögren syndrome.

Pulmonary Langerhans cell histiocytosis with inguinal abscess: Unusual presentation

We report a case of a 30-year-old man who was treated as recurrent right inguinal abscess following a 2-month history of right inguinal swelling and intermittent fever with no respiratory symptoms. Resection of his right inguinal lymph node and the histopathological analysis revealed the diagnosis of Langerhans cell histiocytosis. In addition, the CT of the thorax showed presence of bilateral cystic lung changes consistent with pulmonary Langerhans cell histiocytosis.

Smoking-Related Lung Disease

Smoke from cigarettes and other sources may induce a variety of patterns of lung injury. While smoking related lung diseases, in general, have a better prognosis than many other diffuse lung diseases, they may be a cause of significant symptoms and, in some cases, may even require lung transplantation. On histology, the manifestations of these patterns range from reversible inflammation to irreversible emphysema or fibrosis. High-resolution chest CT plays a critical role in the diagnosis of smoking related lung diseases. It has several roles including (1) helping determine diagnosis, (2) assessing the pattern of injury that is present, (3) evaluating the extent and severity of disease, and (4) determining the response to treatment. The practicing radiologist must have a knowledge of the clinical, pathologic, and imaging features of the differnent patterns of lung injury associated with smoke inhalation.

Effect of cladribine therapy on lung cysts in pulmonary Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a group of disorders with variable presentations and outcomes. Children with LCH primarily have bone and multisystem involvement with little impact of lung involvement and usually no treatment indication for lung disease [1, 2]. Conversely, pulmonary involvement is the main determinant of morbidity and mortality in adults and is usually resistant to first-line chemotherapeutic agents used in children [3]. Pulmonary LCH belongs to the spectrum of LCH and is primarily found in smoker adults. In most cases, quitting smoking results in clinical, functional and radiological improvement at early or nodulo-cystic stages [4]. In those with progressive disease and significant lung function impairment, cladribine (a purine nucleoside analog) has been proposed as rescue therapy for progressive, refractory nodulo-cystic disease [5, 6]. However, there are currently no treatment options for patients with advanced, cystic pulmonary LCH.

Cladribine therapy may be beneficial in advanced forms of pulmonary Langerhans cell histiocytosis, even that with multiple cystic changeshttp://ow.ly/yeLr30i0Tt6

Radiographic Differentiation of Advanced Fibrocystic Lung Diseases

The concept of end-stage lung disease suggests a final common pathway for most diffuse parenchymal lung diseases. In accordance with this concept, end-stage disease is characterized radiographically and pathologically by the presence of extensive honeycombing. However, sequential computed tomographic (CT) scans obtained from patients with chronic diffuse lung disease evolve over time to show various advanced lung disease patterns other than honeycombing. In addition, several radiographically distinct honeycomb patterns, including microcystic, macrocystic, mixed, and combined emphysema and honeycombing, differentiate one advanced lung disease from another. For example, usual interstitial pneumonia (IP) usually shows mixed microcystic and macrocystic honeycombing. In contrast, CT images of long-standing fibrotic nonspecific IP typically show only small, scattered foci of honeycombing; instead, most enlarged airspaces observed in the advanced stage of this disease represent dilatation of bronchioles. In desquamative IP and pulmonary Langerhans cell histiocytosis, focal opacities typically evolve into emphysema-like lesions seen on CT imaging. In combined pulmonary fibrosis and emphysema and sarcoidosis, the cysts tend to be larger than those observed in usual IP. Sequential CT scans in other chronic, diffuse lung diseases also show various distinctive changes. This article highlights radiographic patterns of lung destruction that belie a single common pathway to end-stage lung disease. Recognition of distinct radiographic patterns of lung destruction can help differentiate diffuse parenchymal lung diseases, even in advanced stages of disease evolution.

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

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Amyloid-associated Cystic Lung Disease

BACKGROUND

Amyloid-associated cystic lung disease is rare. It can be associated with collagen vascular disease (CVD). We aimed to describe the clinical, radiology, and pathology findings of this entity.

METHODS

We reviewed the records of subjects having biopsy-proven pulmonary amyloidosis with cystic lung disease demonstrated at high-resolution computed tomography (HRCT). Demographic characteristics, association with CVD and lymphoproliferative disorders, pulmonary function, and pathology results were reviewed. HRCT appearance was analyzed for number, size, distribution, and morphology of cysts and nodules.

RESULTS

Twenty-one subjects (13 female, eight male; median age, 61 years) with cystic pulmonary amyloidosis were identified. The most common pulmonary function patterns were normal (42%) and obstructive (32%). The most common associated CVD was Sjögren syndrome (10 of 12). Nine subjects had no CVD. Cysts tended to be multiple (≥ 10 in 14 of 21, 67%), round (21 of 21, 100%), or lobulated (20 of 21, 95%); thin-walled (< 2 mm in 17 of 21, 81%); and of small (< 1 cm in 21 of 21, 100%) to moderate (1-2 cm in 17 of 21, 81%) size. Peribronchovascular (19 of 21, 90%) and subpleural (19 of 21, 90%) cysts were typically present. Seventeen (81%) subjects had lung nodules, which tended to be numerous (≥ 10 in 10 of 17, 59%; 4-9 in six of 17, 35%). At least one calcified nodule was present in 14 of 17 subjects (82%). Pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) was diagnosed in seven subjects (33%).

CONCLUSIONS

Amyloid-associated cystic lung disease can occur with or without underlying CVD. Cystic lesions in the lung are commonly numerous, often are peribronchovascular or subpleural, and are frequently associated with nodular lesions that are often calcified. MALToma was a relatively frequent association.

[Pulmonary manifestations of Langerhans cell histiocytosis]

Pulmonary Langerhans cell histiocytosis is a rare diffuse cystic interstitial pneumonia of unknown etiology that occurs selectively in young smokers of both genders. The multicenter studies conducted by the reference center have better defined the short and medium terms natural history of the disease and the clinical management of patients. A substantial proportion of patients experience a dramatic decline in their lung function soon after diagnosis. Importantly, smoking cessation is associated with a decreased risk of subsequent deterioration. Cladribine, a purine analogue, chemotherapy may dramatically improve lung function in patients with progressive pulmonary Langerhans cell histiocytosis, but this treatment should be used only in the setting of clinical research. Specific pulmonary hypertension therapies (anti-endothelin receptors, inhibitors of phosphodiesterases) may be used with caution in specialized centres for patients with severe pulmonary hypertension, and seem to be well tolerated. The recent identification of the V600E mutation of the BRAF oncogene in approximately half of the Langerhans cell histiocytosis lesions, including pulmonary granulomas, represents an important step forward in the understanding of the pathogenesis of Langerhans cell histiocytosis. Potentially it opens the way to targeted therapies.

Pulmonary Langerhans Cell Histiocytosis in an Adult Diagnosed with Solitary Inguinal Lymphadenopathy

We herein report an extremely rare case of pulmonary Langerhans cell histiocytosis with a solitary enlarged inguinal lymph node. A 19-year-old man presented with a non-productive cough lasting for over a five-month period and an enlarged left inguinal lymph node that had persisted for four months. A histopathological study of the lymph node specimens found Langerhans cells coupled with eosinophils. Positive immunohistochemical staining for langerin, Cluster of Differentiation 1a, S100 in the Langerhans cells confirmed the diagnosis, and a mildly impaired ventilation function in addition to multiple peripheral pulmonary cystic lesions were detected. The patient was managed with prednisone (0.5 mg/kg daily), with slow tapering over several months.

Pulmonary langerhans cell histiocytosis: case series and literature review

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare disease with insidious onset and nonspecific manifestations. The objective of this article was to characterize the clinical manifestations and features of PLCH by retrospectively analyzing clinical data of patients with PLCH in addition to simultaneous review of literature.A retrospective analysis was conducted on clinical data of patients with PLCH (n = 7), whose conditions were diagnosed by biopsy from pulmonary tissue (n = 6) or enlarged lymph nodes in the neck (n = 1) and confirmed by PLCH typical radiological features on computed tomography (CT) scan, between January 2001 and September 2012 at the Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China. The review of published reports was made to further emphasize the clinical manifestation and radiological features of PLCH.Long history of cigarette smoking was found in 6 patients. Two patients had recurrent pneumothorax and the other 2 had pulmonary arterial hypertension (World Health Organization group 5 pulmonary hypertension), diagnosed through ultrasonic cardiogram. The nodular shadows were revealed by chest CT scan in 5 patients, cystic shadows in 5 patients, and reticular shadows in 2 patients, as major manifestations, respectively; most of the lesions were located in the middle or upper segments of the lung. The obvious shrank of lesion was found in 1 patient after completely quitting smoking.The pathogenesis of PLCH might be closely associated with smoking. The cystic or nodular lesion was the typical radiological features. Further prospective studies with large sample size are required to further validate the study results and understand the clinical characteristics of PLCH to avoid misdiagnosis.

Pulmonary Langerhans cell histiocytosis: the many faces of presentation at initial CT scan

Objectives

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare interstitial granulomatous disease that usually affects young adults who are smokers. Chest computed tomography (CT) allows a confident diagnosis of PLCH only in typical presentation, when nodules, cavitated nodules and cysts coexist and predominate in the upper and middle lungs.

Methods

This article includes a pictorial essay of typical and atypical presentations of PLCH at initial chest CT. Various appearances of PLCH are illustrated and possible differential diagnosis is discussed.

Results

PLCH can present with some aspecific features that may cause diagnosis of the initial disease to be overlooked or other pulmonary diseases to be suspected. In cases of nodule presentation alone, the main differential diagnosis should include lung metastasis, tuberculosis and other infections, sarcoidosis, silicosis and Wegener’s disease. In cases of cysts alone, the most common diseases to be differentiated are centrilobular emphysema and lymphangiomyomatosis. Clinical symptoms are usually non-specific, although a history of cigarette smoking, coupled with the presence of typical or suggestive findings at imaging, is key to suspecting the disease. Atypical presentations require surgical biopsy for diagnosis.

Conclusions

The radiologist should be familiar with PLCH imaging features to correctly diagnose the disease or need for further investigation.

Teaching Points

• PLCH is a rare interstitial smoking-related disease that usually affects young adults.

• The typical first CT shows a mix of nodules, cavitary nodules and cysts in the upper-middle lungs.

• Atypical appearance, either cysts or nodules alone, mandates that other diagnoses be considered.

• Lung cystic involvement correlates with lung function abnormalities and predicts functional decline.

• Integration of the clinical history and imaging results is key to diagnosis.

[Adult pulmonary Langerhans' cell histiocytosis: approach to the reality of the Spanish population]

BACKGROUND AND OBJECTIVE

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare respiratory disease closely associated with smoking. The aim of the study is to know the reality of PLCH in the Catalonian population.

MATERIAL AND METHODS

We included all patients diagnosed of PLCH in 8 different Catalonian hospitals from April 2011 to December 2012. Epidemiologic, clinical, radiological, functional, diagnostic and therapeutic variables were collected, both at the beginning and at the last visit of the process.

RESULTS

Thirty two patients were included. Overall, patients were middle-aged (38 years), with no gender predominance. Most of them were smokers (71.9%). The main pulmonary function values (forced vital capacity 75.9%, forced expiratory volume in one second 68.9%, diffusing capacity of the lung for carbon monoxide 59.6%) and radiological findings (cysts 89.7%, nodules 60.3%) showed no significant changes during evolution. However, the disease progressed with a worsening lung function in 34.4% of cases. The analysis of the functional outcome (forced vital capacity, forced expiratory volume in one second, and diffusing capacity of the lung for carbon monoxide) did not reveal significant differences according to the persistence or not of smoking (P<0.05).

CONCLUSION

Our patients with PLCH had similar clinical and radiological characteristics to those described in other populations. The results observed regarding the relationship with smoking suggest that there may be other factors beyond smoking, which influence on the evolution of the disease. It therefore seems advisable to design prospective studies to investigate this aspect.