Involvement In Erdheim-Chester Disease Research Articles

Atypical Bone Involvement in Erdheim-Chester Disease Showing No or Subtle Structure Changes and Increased Activity on FDG PET/CT.

Bones are the most common sites involved in Erdheim-Chester disease. On imaging, the bone involvement in Erdheim-Chester disease typically presents as osteosclerotic lesions, and osteolytic lesions are unusual. Bone lesions showing no or subtle structure changes are rarely reported. We describe FDG PET/CT findings in a case of Erdheim-Chester disease with atypical bone involvement. The bone lesions showed no or subtle structure changes without obvious osteosclerosis or osteolysis on radiographs and CT, and increased FDG activity mimicking lymphoma. Familiarity with these atypical imaging findings of bone involvement in Erdheim-Chester disease is helpful for the diagnosis.

The Spectrum of Cardiac Involvement in Erdheim-Chester Disease is Broader than Previously Thought

The Spectrum of Cardiac Involvement in Erdheim-Chester Disease is Broader than Previously Thought

Skeletal involvement in Erdheim-Chester disease: Multimodality imaging features and association with the BRAFV600E mutation

ObjectiveThe aim of this study was to characterize the distribution of skeletal involvement in Erdheim-Chester disease (ECD) by using radiography, computed tomography (CT), 18F-FDG positron emission tomography/computed tomography (PET/CT), and bone scans, as well as looking for associations with the BRAFV600E mutation. Material and methodsProspective study of 50 consecutive patients with biopsy-confirmed ECD who had radiographs, CT, 18F-FDG PET/CT, and Tc-99m MDP bone scans. At least two experienced radiologists with expertise in the relevant imaging studies analyzed the images. Summary statistics were expressed as the frequency with percentages for categorical data. Fisher's exact test, as well as odds ratios (OR) with 95 % confidence intervals (CI), were used to link imaging findings to BRAFV600E mutation. The probability for co-occurrence of bone involvement at different locations was calculated and graphed as a heat map. ResultsAll 50 cases revealed skeletal involvement at different regions of the skeleton. The BRAFV600E mutation, which was found in 24 patients, was correlated with femoral and tibial involvement on 18F-FDG PET/CT and bone scan. The appearance of changes on the femoral, tibial, fibular, and humeral involvement showed correlation with each other based on heat maps of skeletal involvement on CT. ConclusionThis study reports the distribution of skeletal involvement in a cohort of patients with ECD. CT is able to detect the majority of ECD skeletal involvement. Considering the complementary nature of information from different modalities, imaging of ECD skeletal involvement is optimized by using a multi-modality strategy.

Impact of BRAFV600E mutation on aggressiveness and outcomes in adult clonal histiocytosis.

Histiocytoses encompass a wide spectrum of diseases, all characterized by tissue infiltration by CD68+ histiocytes. Most adult histiocytoses are considered clonal diseases because they highlight recurrent somatic mutations in the MAP-kinase pathway gene, primarily BRAF. The presence of BRAF mutation is associated with widespread disease in children with Langerhans cell histiocytosis (LCH) or cardiovascular/neurological involvement in Erdheim-Chester disease (ECD). Nevertheless, few data are available on adult clonal histiocytosis. This is why we have conducted a retrospective study of all patients with clonal histiocytosis in our institution and present the data according to the presence of BRAF mutation. Among 27 adult patients (10 ECD, 10 LCH, 5 Rosai-Dorfman disease (RDD), and 3 mixed ECD/LCH), 11 (39%) have BRAF mutation with gain of function (n = 9) and deletion (n = 2). Those patients had frequent multicentric disease with risk organ involvement, especially the brain and cardiovascular system. They had frequent associated myeloid neoplasms (mostly chronic myelomonocytic leukemia) and received more frequently targeted therapy as the front-line therapy. Nevertheless, its presence did not affect the overall survival or relapse-free survival probably due to the emergence of efficient therapies. To conclude, rapid and accurate molecular establishment in adult clonal histiocytoses is crucial because BRAFV600E mutation correlates with multicentric disease with organ involvement and incomplete metabolic response.

Longitudinal assessment of cardiac involvement in Erdheim-Chester disease using cardiac magnetic resonance imaging.

7067 Background: Erdheim-Chester disease (ECD) is a rare multi-systemic non-Langerhans cell histiocytosis that affects the heart in nearly half of patients. Atrial infiltration and pericardial effusion are the hallmarks of cardiac involvement and can lead to clinical complications (conduction disorders, coronary artery stenosis, tamponade, constrictive pericarditis). Evolution under treatment is poorly studied. We aimed to investigate the evolution of cardiac involvement in ECD using cardiac magnetic resonance (CMR) imaging. Methods: All ECD patients with a CMR imaging disclosing a cardiac involvement and who underwent at least one follow-up CMR imaging between 2005 and 2020 at a French tertiary center were retrospectively included. First and last CMR imaging were compared. Multivariable analysis was performed to search for independent predictors of cardiac involvement resolution. Variables were included in the model if their P-value was < 0.1 on univariable analysis. Results: Overall, 46 patients were included. Median age at first imaging was 63 years [53-69]. Median delay between the first and the last imaging was 4 years [2-7]. BRAFV600E mutation was present in 43 patients (94%). Patients received a median of 2 [1-3] treatments. All patients (100%) had cardiac involvement at baseline. Right atrio-ventricular sulcus (RAVS) was infiltrated in 38 patients (83%) and was the main cardiac feature.Overall, complete regression was observed in 6 patients (13%), partial regression in 26 patients (56%), stable imaging in 12 patients (26%), and worsening in 2 patients (5%). In patients with RAVS infiltration, complete regression was observed in 5 patients (16%) and partial regression was seen 22 patients (58%) regression. On univariable analysis, patients with regression of their infiltration had a lower rate of death (16% versus 64%, P= 0.002), a higher rate of atrial infiltration late gadolinium enhancement (LGE) (97% versus 71%, P= 0.01), a higher rate of hydronephrosis (50% versus 14%, P= 0.03) and a lower rate of interferon prescription (69% versus 100%, P= 0.02). A similar rate of vemurafenib use was observed in both groups (69% versus 54%, P= 0.3). On multivariable analysis, death remained significantly associated with follow-up imaging status (ß = -2.3 P= 0.01), while atrial infiltration LGE (ß = 2.7, P= 0.06), hydronephrosis (ß = 1.6, P= 0.1) and treatment with interferon (ß = -16, P= 1) were no longer significantly associated with imaging status. Conclusions: Partial or complete resolution of cardiac involvement was observed in 69% of patients with ECD and was significantly associated with a lower rate of death on multivariable analysis.

Prevalence, patterns and outcomes of cardiac involvement in Erdheim-Chester disease.

Cardiac involvement of Erdheim-Chester disease (ECD), a rare L group histiocytosis, has been reported to be associated with poor outcomes, but systematic studies are lacking. The present study aimed to investigate the prevalence, clinical features, imaging features, and prognosis of cardiac involvement in ECD in a large series. All patients with ECD who underwent cardiac magnetic resonance (CMR) imaging between 2003 and 2019 at a French tertiary center were retrospectively included. Primary outcome was all-cause mortality. Secondary outcomes were pericarditis, cardiac tamponade, conduction disorders, device implantation and coronary artery disease (CAD). A total of 200 patients were included [63 (54-71) years, 30% female, 58% BRAFV600E mutated]. Median follow-up was 5.5 years (3.3-9 years). On CMR, right atrioventricular sulcus infiltration was observed in 37% of patients, and pericardial effusion was seen in 24% of patients. In total, 8 patients (4%) had pericarditis (7 acute, 1 constrictive), 10 patients (5%) had cardiac tamponade, 5 patients (2.5%) had ECD-related high-degree conduction disorders, and 45 patients (23%) had CAD. Overall, cardiac involvement was present in 96 patients (48%) and was associated with BRAFV600E mutation [Odds ratio (OR) = 7.4, 95% confidence interval (CI) (3.5-16.8), P < 0.001] and ECD-related clinical events [OR = 5, 95%CI (1.5-21.2), P = 0.004] but not with lower survival in multivariate analysis [adjusted hazard ratio (HR) = 1.4, 95% CI (0.8-2.5), P = 0.2]. Cardiac involvement is present in nearly half of ECD patients and is associated with BRAFV600E mutation and complications (pericarditis, cardiac tamponade, and conduction disorders) but not with lower survival.

Surgical Appearance of Aortic Involvement in Erdheim-Chester Disease: A Report of Two Cases

Protože Erdheimova-Chesterova nemoc (Erdheim-Chester disease, ECD), známá i pod označením polyostotická sklerotická histiocytóza, působí i na cévní struktury, může být mylně diagnostikována jako ischemická choroba dolních končetin. Postižení aorty při ECD obvykle odhalí rentgenové vyšetření. Dosud však nemáme k dispozici dostatek informací o vzhledu postižení během chirurgického výkonu ani o léčbě postižení aorty při ECD. V tomto článku popisujeme případ pacienta s postižením vzestupné aorty zjištěným náhodně při provádění koronárního bypassu a dalšího pacienta s postižením břišní aorty připomínajícím aortoiliackou okluzivní nemoc. &#169; 2022, ČKS.

NT-Probnp and High-Sensitivity Troponin T Fail to Detect Cardiac Involvement in Erdheim-Chester Disease

NT-Probnp and High-Sensitivity Troponin T Fail to Detect Cardiac Involvement in Erdheim-Chester Disease

Abdominal Extrarenal Involvement in Erdheim-Chester Disease in a Cohort of 304 Patients

This cohort study estimates the prevalence of nonretroperitoneal abdominal organ involvement in Erdheim-Chester disease in a large cohort of patients.

Pancreatic involvement in Erdheim-Chester disease: a case report and review of the literature

BackgroundErdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis characterized by infiltration of lipid-laden foamy macrophages within different tissues. Clinical manifestations of ECD are highly heterogeneous. Bone lesions are found in 80%-95% of patients, while extraosseous lesions usually involve the cardiovascular system, retroperitoneum, central nervous system (CNS), and skin. Pancreatic involvement in ECD has barely been reported.Case presentationA 29-year-old female initially presented with menoxenia, diabetes insipidus and diabetes mellitus. 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET/CT) revealed hypermetabolic foci in the bilateral frontal lobe, saddle area, and pancreas. A 99mTc-MDP bone scrintigraphy scan revealed symmetrical increased uptake in distal femoral and proximal tibial metaphysis, which was confirmed to be osteosclerosis by high-resolution peripheral quantitative computed tomography. The patient underwent incomplete resection of the sellar mass. Histological examination of biopsies showed histiocytic aggregates, which were positive for S100 and negative for CD1a and CD207 on immunohistochemistry. Enhanced abdominal CT scan showed hypointense nodules within the body and tail of the pancreas. Endoscopic ultrasonography guided fine-needle aspiration (EUS-FNA) found no evidence of malignancy. She was diagnosed with ECD and treated with high-dose IFN-α. Repeated examinations at three-and eight-months post treatment revealed markedly reduction of both intracranial and pancreatic lesions.ConclusionsECD is a rare histiocytic neoplasm that can involve almost every organ, whereas pancreatic involvement has barely been reported to date. Here, we present the rare case of pancreatic lesions in ECD that responded well to interferon-α. We further reviewed reports of pancreatic involvement in histiocytic disorders and concluded the characteristics of such lesions to help diagnosis and treatment, in which these lesions mimicked pancreatic adenocarcinoma and caused unnecessary invasive surgeries.

Multimodality imaging of cardiac involvement in Erdheim-Chester disease.

Multimodality imaging of cardiac involvement in Erdheim-Chester disease.

Central nervous system involvement in Erdheim-Chester disease: An observational cohort study.

CNS involvement in Erdheim-Chester disease (ECD) leads to substantial morbidity and mortality. To assess CNS manifestations in a French cohort of 253 patients with ECD, we determined clinical characteristics and outcomes, including those under targeted therapies. This was a retrospective longitudinal study. CNS manifestations were determined by clinical examination and brain or spine MRI. Targeted therapy efficacy was assessed using global assessment from a physician and a radiologist. The study was approved by the ethics committee Comité de Protection des Personnes Ile de France III. Ninety-seven of 253 patients (38%) with ECD had CNS involvement. CNS involvement was significantly associated with a younger age at diagnosis (mean 55.5 years) and at symptom onset (mean 50.5 years), as well as with the presence of the BRAF V600E mutation (in 77% of cases), xanthelasma (34%), and diabetes insipidus (36%). Median survival among patients with CNS involvement was significantly lower than that of patients with ECD without CNS involvement (124 months vs 146 months, p = 0.03). Seventy-four CNS MRIs were centrally reviewed, which showed 3 patterns: tumoral in 66%, pseudo-degenerative in 50%, and vascular in 18%. Targeted therapy (BRAF or MEK inhibitors) was associated with improved symptoms in 43% of patients and MRI improvement in 45%. CNS manifestations are typically associated with poor prognosis in patients with ECD. Three distinct patterns can be recognized: tumoral, pseudodegenerative, and vascular. This study provides Class III evidence that targeted therapy leads to clinical or imaging improvement in almost 50% of patients.

Association of BRAF V600E with Hypothalamic-Pituitary-Adrenal Axis Involvement in Erdheim-Chester Disease

• Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterized by uncontrolled inflammation resulting in fibro-inflammatory damage of multiple organs, including the hypothalamic-pituitary-adrenal (HPA) axis. • Glucocorticoid insufficiency may occur and is associated with an increased burden of disease and an increased risk of adrenal crisis. • HPA axis in ECD tends to involve the adrenal glands in BRAF V600E-positive individuals, without influencing the rates of low cortisol levels, although there is a poor biochemical-radiological concordance in ECD. • In this cohort, most subjects with HPA axis involvement did not require glucocorticoid or mineralocorticoid therapy. • This study systematically demonstrates an association between the somatic activating BRAF V600E variant and the presence of radiographic and biochemical HPA axis involvement in ECD subjects. Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis characterized by uncontrolled inflammation resulting in fibro-inflammatory damage of multiple organs, including the hypothalamic-pituitary-adrenal (HPA) axis. Glucocorticoid insufficiency may occur and is associated with an increased burden of disease and an increased risk of adrenal crisis. Sixty-one ECD subjects (46 males, age 54.3 ± 10.8 years) were evaluated; 56.1% (32/57) harbored a somatic activating BRAF V600E variant. Adrenal gland and sellar or suprasellar involvement was present in 18/57 (31.6%) and 9/57 (15.8%) subjects on computed tomography or magnetic resonance imaging, respectively. The BRAF -positive group was more likely to have adrenal gland involvement (56.2% vs. 20.0%; odds ratio (OR) 5.8, 95% confidence interval (CI) 1.5-17.1, P=0.008), with comparable rates for sellar or suprasellar involvement (28.1% vs. 20.0%; OR 1.6, 95% CI 0.5-5.4, P=0.5) and low random morning cortisol values (37.5% vs. 32.0%; OR 1.3, 95% CI 0.4-3.8, P=0.7). High-sensitivity C-reactive protein was significantly higher in the BRAF V600E-positive group with adrenal involvement when compared to the BRAF V600E-negative group without adrenal involvement (mean concentration: 40 mg/dL vs. 5 mg/dL, P=0.046). HPA axis in ECD tends to involve the adrenal glands in BRAF V600E-positive individuals, without influencing the rates of low cortisol levels, although there is a poor biochemical-radiological concordance in ECD. In this cohort, most subjects with HPA axis involvement did not require glucocorticoid or mineralocorticoid therapy. This study systematically demonstrates an association between the somatic activating BRAF V600E variant and the presence of radiographic and biochemical HPA axis involvement in ECD subjects. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01417520

Rare Cardiac Mass Assessed by Cardiac Magnetic Resonance

Abstract A 43 year old male was referred to our center for assessment of the cardiac involvement in Erdheim-Chester disease (EHD) by cardiac magnetic resonance (CMR). The patient presented with a history of bone involvement as well as retroperitoneal mass, demonstrated to consist fibrosis as well as histiocyte infiltration. The CMR examination included cine (SSFP – steady state free procession), T1 weighted (T1w) and T2 weighted (T2w) sequences, as well as late enhancement images 10 minutes after gadolinium based contrast injection (0.2 mmol/kg). The acquired images showed normal dimensions and function for both right and left cardiac chambers. However, a cardiac mass was revealed in the free wall of the right atrium and the junction with the right ventricle, with clear borders and a diameter of 2.5 cm (Image 1). The tissue was best viewed on axial sequences and was isointense on cine, T1w and T2w images and was mildly enhanced on LGE images. Consequently, the diagnosis of cardiac involvement in EHD was confirmed. The patient was started on specific treatment for EHD and 3-year CMR follow-up showed regression of cardiac involvement. Erdheim-Chester disease is a rare disorder most frequently characterized by non-Langerhans histiocytic multifocal osteosclerotic lesions, with multisystemic granulomatosis and widespread manifestations, as well as highly variable severity(1). ECD affects the cardiovascular system in 75% of patients with infiltration of the pericardium and the right atrioventricular septum being the most common presentation. Typically the mass appears isointense on T1 and T2 weighted images and has low contrast enhancement, as was the case in our patient. In approximately 60% of cases death occurs because of cardiac complications, like pericardial tamponade, myocardial infarction, cardiomyopathy or arrhythmias(2). Patients may sometimes be successfully treated with biologic therapy, interferon alpha or radiotherapy.

Classification and Prognosis of Central Nervous System Involvement in Erdheim-Chester Disease

Background: Erdheim-Chester disease (ECD) is a non-Langerhans cell histiocytosis, characterized by the infiltration of tissues by foamy CD68+CD1a- histiocytes, with 1500 known-cases since 90 years. Mutations activating the MAPK pathway are found in more than 80% of ECD patients, mainly the BRAFV600E in 57 to 70%. Central nervous system (CNS) involvement during ECD lead to significant morbidity and mortality. We assessed CNS manifestations in a French cohort of 253 ECD patients. Since 2012, close to 200 patients worldwide with multi-systemic and refractory ECD (e.g. heart and/or CNS involvements) have benefited from BRAF and MEK inhibitors, which have proven highly beneficial. Methods: CNS manifestations were determined by clinical examination and brain and/or spine magnetic resonance imaging (MRI). Targeted therapy efficacy was assessed using physician and radiologist global assessment. Results: Ninety-seven (38%) among the 253 of the whole cohort of ECD patients had CNS involvement. CNS involvement was significantly associated with a younger age at diagnosis (mean 55.5 years) and at symptoms onset (mean 50.5 years), and also with the presence of the BRAFV600E mutation (in 77% of cases), xanthelasma (34%), and diabetes insipidus (36%). Median survival among patients with CNS involvement was significantly lower than in ECD patients without CNS involvement (124 months versus 146 months, p=0.03). Seventy-four CNS MRI were centrally reviewed, corresponding to 3 patterns: tumoral in 66%, degenerative in 50%, and vascular in 18%. Targeted therapy (BRAF and/or MEK inhibitors) was associated with improvement of symptoms in 43% of patients, and MRI improvement in 45%. Conclusions: CNS manifestations are typically associated with a poor prognosis in ECD. Three distinct patterns may be recognized: tumoral, degenerative, and vascular. Targeted therapy leads to clinical and/or imaging improvement in almost 50% of patients. OffLabel Disclosure: Targeted therapies such as BRAF inhibitor (vemurafenib) and MEK inhibitor (cobimetinib) are used in severe histiocytosis in EU but are off label

Arterial involvement in Erdheim-Chester disease: A retrospective cohort study.

Erdheim-Chester disease (ECD) is a rare histiocytosis of the "L" (Langerhans) group with multisystem involvement that can affect the large and medium-sized arteries mimicking vasculitis. Aortic involvement is common but the frequency and outcome of aortic branch vessel abnormalities are less well described.Patients with ECD were retrospectively identified. Images containing information of arterial involvement within 6 months of diagnosis were considered baseline and compared to last follow-up studies. Two physicians independently reviewed the studies to evaluate for presence of abnormalities attributable to ECD. Age and sex-adjusted logistic regression models were used to examine associations between patient characteristics and vessel involvement at baseline.Among a cohort of 64 patients with ECD, 63 had baseline imaging of vascular structures. ECD involvement of at least 1 segment of the aorta was observed in 56%. Abnormalities were also observed in aortic arch branches (26%), visceral branch arteries (40%), iliofemoral arteries (31%), coronary (5%), and pulmonary (3%) arteries. Perinephric fibrosis was strongly associated with the identification of abnormalities in the thoracic aorta (OR 4.92 [1.54, 15.75]; P = .007), abdominal aorta (OR 7.57 [2.28, 25.07]; P = .001) and visceral branch arteries (OR 6.05 [1.52, 24.03]; P = .01) but not pelvic/lower extremity arteries. Complete normalization of arterial abnormalities at follow-up was only observed in 9% or less of arterial segments involved at baseline.Aortic and aortic branch vessel abnormalities are frequently observed in patients with ECD and are often asymptomatic. Partial and/or complete resolution of arterial findings is uncommon.

Thoracic involvement in Erdheim-Chester disease: computed tomography imaging findings and their association with the BRAFV600E mutation.

To investigate the computed tomography (CT) thoracic findings in Erdheim-Chester disease (ECD) and evaluate the association of these findings with the BRAFV600E mutation. This was a prospective study of patients with ECD (n=61, men=46) who underwent thoracic CT imaging. CT examinations were independently interpreted by two experienced radiologists. Association of imaging findings with BRAFV600E was achieved via the Chi-square or Fisher's exact test and odds ratios (OR) with 95% confidence intervals (CI), as appropriate. Fifty-five ECD patients (90%) showed pulmonary findings, which included interlobular septal thickening (69%), pulmonary nodules (62%), airway thickening (13%) and ground glass opacities (36%). Pulmonary nodules were classified by the pattern of distribution: subpleural regions (36%), lung parenchyma (13%) and both regions (13%). Pleural and mediastinal involvement were present in 15% and 62% of cases, respectively. The most common mediastinal finding was sheathing of the right coronary artery (34%), followed by sheathing of the thoracic aorta (30%). The BRAFV600E mutation, positive in 31 patients, was associated with the frequency of sheathing of the coronary arteries (p = 0.01). Of the thoracic findings reported in this study, we found a statistically significant positive association between the BRAFV600E mutation and presence of coronary artery sheathing. • To assess the degree of thoracic involvement in ECD with CT. • BRAF V600E mutation has a high association with right coronary artery sheathing. • BRAF V600E genetic testing detects patients at high risk of developing RCA sheathing.

Abdominal involvement in Erdheim-Chester disease (ECD): MRI and CT imaging findings and their association with BRAFV600E mutation.

To use magnetic resonance imaging (MRI) and computed tomography (CT) to define abdominal involvement in Erdheim-Chester disease (ECD), and to investigate the association between these findings and the BRAFV600E mutation. This prospective study was performed on 61 ECD patients (46 men). The MRI and CT imaging studies were reviewed independently by two experienced radiologists. The association between BRAFV600E mutation and imaging findings was analysed using Fisher's exact test, and odds ratios with 95% confidence intervals. Perinephric infiltration was the most common finding (67%), followed by involvement of proximal ureters (61%). In 56% of cases, infiltration extended to the renal sinuses, and in 38% caused hydronephrosis. Adrenal gland infiltration was present in 48% of patients. Infiltration of renal artery (49%) and aorta (43%) were the most common vascular findings, followed by sheathing of celiac, superior mesenteric artery (SMA) or inferior mesenteric artery (IMA) (23%). The BRAFV600E mutation was positive in 53% of patients with interpretable BRAF sequencing. There was a statistically significant association between this mutation and perinephric infiltration (p = 0.003), renal sinus involvement (p < 0.001), infiltration of proximal ureters (p < 0.001), hydronephrosis (p < 0.001), adrenal gland involvement (p < 0.001), periaortic infiltration (p = 0.03), sheathing or stenosis of renal artery (p < 0.001) and sheathing of other aortic branches (p = 0.04). Renal and vascular structures are the most commonly affected abdominal organs in ECD patients. Some of these findings have significant positive association with the BRAFV600E mutation. • Abdominal imaging plays a crucial role in management of Erdheim-Chester disease. • Significant associations exist between BRAF V600E mutation and several abdominal imaging findings. • Considering several associations, evaluating BRAFV600E mutation status is recommended in ECD patients.

Clinical and pathological characteristics of Erdheim-Chester disease involving the lungs

Objective: To explore the clinical manifestations, pathological features, differential diagnosis and gene mutation status in patients with pulmonary involvement of Erdheim-Chester disease (ECD). Methods: The clinical data of 4 cases of Erdheim-Chester disease admitted to Peking Union Medical College Hospital from October 2014 to August 2016 were examined for imaging, microscopic and immunohistochemitry findings, and BRAFV600E mutation. The related literatures were reviewed. Results: Among the 4 cases, there were 3 males and 1 female, aging from 7 to 47 years, and the average age was 34.5 years. They complained of chest tightness, shortness of breath and bone pain. They all had multiple bone lesions, involving the long bones, skulls and vertebrae, and imaging showed increased bone uptake and bone sclerosis. CT scan showed pleural thickening or pleural effusion(4/4), widened lobular septa(3/4), bronchial vascular bundle thickening(3/4), multiple patchy ground glass and solid shadows(4/4), and cystic shadows(1/4). Multiple bone lesions were the main extrapulmonary manifestations. All the cases had multiple bone lesions, involving the long bones, skulls and vertebrae, and showed increased bone uptake and bone sclerosis. Surgical biopsy of the thoracic tissue was performed in all 4 cases (pleural in 1 case, lung in 2, anterior mediastinal mass in 1). Microscopically, the lesion was composed of spindle-shaped fibroblasts and foamy histiocytes enmeshed in reactive fibrous tissue. Lymphocytes and plasma cells were also found. Immunohistochemically, all the histiocytes were positive for CD(68), and none of them expressed CD1a. All cases were detected by real-time quantitative PCR for BRAFV600E gene mutation. Conclusions: The pulmonary involvement of Erdheim-Chester disease is rare, with clinical manifestations of chest tightness, shortness of breath, and some have no obvious respiratory symptoms. Pulmonary involvement in Erdheim-Chester disease has important manifestations, in which foam-like tissue cells with diffuse distribution along the lymphatic enmeshed in reactive fibrous tissue. It should be differentiated from diffuse interstitial lung diseases and metastatic tumors. The clinical features are often manifested as pleural thickening and pleural effusion, with multiple bone sclerosis lesions.BRAFV600E mutation detection is helpful for the diagnosis.

Pulmonary Presentation Without Concurrent Bone Involvement in Erdheim-Chester Disease: A Report of Two Cases

Pulmonary Presentation Without Concurrent Bone Involvement in Erdheim-Chester Disease: A Report of Two Cases