Erdheim-Chester Disease: Investigating the Correlation between Targeted Treatment Therapy and Disease Outcomes.

A retrospective analysis of 20 adult patients with histopathological and clinical diagnoses of ECD was conducted at a single institution over a twenty-year period (2002-2022). Clinical responses were compared on the basis of treatments rendered, which included chemotherapy, immunotherapy, systemic corticosteroids, surgery and radiation, or targeted agents, referring to any small molecular inhibitors. Treatment response evaluation varied by the anatomic site(s) of disease, the extent of disease at diagnosis, and the imaging modality employed. In this analysis, patients were treated with a combination of targeted agents, myelosuppressive therapies, and radiation at various points in their disease courses. Of these, the most common treatment modality rendered was targeted therapy, employed in 11 of 20 patients. Partial responses or better were observed in 15 of 20 patients. Rates of stable disease trended towards being more frequent with targeted therapy versus conventional therapy but did not reach significance (p = 0.2967). Complete response rates trended towards being more common with conventional therapy than molecular (p = 0.5) but were equivocal overall. Trends of peripheral blood absolute monocytes with relation to disease activity were reviewed as recent literature implied that monocyte levels surrounding disease progression were of potential prognostic significance in histiocytic diseases. Amongst the patients who progressed at any point during their treatment course, absolute monocyte count (in K/µL) was identified at the closest available timepoint prior to or following disease progression and at the lowest value (nadir) following re-institution of therapy prior to any additional agent(s) being employed. There was no statistically significant difference in either of these monocyte values nor in disease outcomes with respect to treatments rendered within our cohort. However, our cohort consists of a heterogenous population of patients with ECD with data that highlights several trends over a longitudinal period, spanning the advent of targeted therapy. Significant differences are anticipated in ongoing analyses.

Pulmonary Erdheim-Chester Disease With BRAF-AGAP3 Fusion: Late-Onset Osteolytic Femoral Lesions Despite Long-Term Pulmonary Stabilization With Corticosteroid.

Erdheim-Chester disease (ECD) is a rare inflammatory myeloid neoplasm affecting multiple systems and organs. The patient is a 38-year-old male with ECD complicated with pulmonary and cutaneous manifestations but without bone lesions diagnosed in 2008. Initial treatment with oral and inhaled corticosteroids achieved persistent favorable disease remission. However, atypical late-onset bone lesions developed in the bilateral femur in 2021. Although BRAF-V600E mutation was negative in the lung specimen at diagnosis, the next-generation gene sequence using biopsied bone lesions revealed a rare BRAF-AGAP3 fusion, leading to the administration of trametinib. This is the first report describing ECD harboring BRAF-AGAP3 fusion successfully treated with trametinib. Our case presents a unique clinical course in which late-onset osteolytic bone lesions developed despite a long-term stabilization of pulmonary lesions with low-dose oral and inhaled corticosteroids.

Erdheim-Chester Disease presenting with constrictive pericarditis: A case report and review of the literature.

Erdheim-Chester Disease (ECD) is a rare form of histiocytosis characterized by xanthomatous infiltration of affected organs. We present a case of a 62-year-old man with ECD initially presenting with constrictive pericarditis. Comprehensive imaging revealed systemic involvement, including the skeleton, orbit, pituitary, lung, kidney, and retroperitoneum, despite the absence of related symptoms. The diagnosis of ECD was eventually confirmed through histopathological evidence from a CT-guided biopsy. The patient responded well to interferon-α2b treatment, with gradual symptom amelioration and improvement in imaging and laboratory findings over a 5-month follow-up period. This case highlights the importance of considering ECD in the differential diagnosis of constrictive pericarditis and the utility of multimodal imaging for accurate diagnosis and management of this rare disease. The patient's positive response to treatment also highlights the potential for effective management of ECD, particularly with early diagnosis and intervention.

Case report: Targeted treatment strategies for Erdheim-Chester disease.

Introduction: Erdheim-Chester disease (ECD) is a rare disease that belongs to the group of Dendritic and histiocytic neoplasms. Only 2000 cases have been reported worldwide. It can present with a wide range of symptoms, making a differential diagnosis especially difficult. The primary and most important diagnostic tool is a biopsy of the affected organ/tissue. Nowadays the analysis of different mutations affecting the BRAF and MAPK pathways makes it possible to use targeted treatments, such as vemurafenib, dabrafenib, or cobimetinib. Objective: Our aim is to present the results of three male patients treated in our hematology department. Results: Our BRAF mutation-positive patient presented with retroperitoneal tissue proliferation and diabetes insipidus. The initial therapy of choice was dabrafenib. After 3 months of treatment, 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) scans showed regression, and after 2 years of treatment, no disease activity was detected. In our second patient, a recurrent febrile state (not explained by other reasons) and diabetes insipidus suggested the diagnosis. A femoral bone biopsy confirmed BRAF-negative ECD. The first-line therapy was interferon-alpha. After 3 months of treatment, no response was observed on 18FDG-PET/CT, and treatment with cobimetinib was started. The control 18FDG-PET/CT imaging was negative. Our third patient was evaluated for dyspnea, and a CT scan showed fibrosis with hilar lymphadenomegaly. A lung biopsy confirmed BRAF-negative ECD. We started treatment with interferon-alpha, but unfortunately, no improvement was observed. Second-line treatment with cobimetinib resulted in a partial metabolic response (PMR) according to control 18FDG-PET/CT. Conclusions: Our results demonstrate that an appropriately chosen treatment can lead to a good therapeutic response, but dose reduction may be necessary due to side effects. With advanced targeted therapeutic treatment options, survival and quality of life are significantly improved.

Erdheim­Chester disease of multisystem involvement with delayed diagnosis: A case report and literature review.

Erdheim-Chester disease (ECD) is a rare tumor of histiocytic origin, characterized by foamy or lipid-laden histiocytes mixed or surrounded by fibrosis that infiltrate multiple organs. Misdiagnosis is common due to the diversity of clinical presentations. The present study reported a case of ECD with the involvements of bone, cardiac, aorta and retroperitoneum. The patient had no obvious clinical symptoms and no noteworthy foamy histiocytes or Touton giant cells were found on pathological examination, delaying the diagnosis. The patient was a young male found to have pericardial effusion on physical examination, and computed tomography (CT) revealed soft tissue infiltrates in the retroperitoneum and around the aorta. A mediastinal biopsy revealed fibrous connective tissue with small-vessel hyperplasia and acute-chronic inflammatory cell infiltration. The initial diagnosis was retroperitoneal fibrosis (RPF), and hormonal and tamoxifen treatments were administered. The patient presented with oliguria, eyelid edema and fever four years later. A repeat CT revealed an increase in the extent of tissue infiltration and pericardial effusion compared with the previous CT. Subsequent cardiac magnetic resonance imaging revealed massive thickening in the form of fibrotic tissue infiltrating the heart and surrounding thoracic and abdominal aorta. Single photon emission CT revealed multiple areas of increased bone metabolism, particularly symmetrical involvement of the long bones of both lower extremities. A biopsy of the perirenal tissue revealed fibrous tissue and a small number of lymphocytes and macrophages [typical foamy histiocytes observed via x200 magnification and hematoxylin-eosin (HE) staining, no presence of xanthogranuloma or Touton giant cells]. After a comprehensive evaluation and ruling out other diseases, the diagnosis of ECD was determined. The prognosis of this disease is poor; early diagnosis is critical and requires accurate judgment by clinicians. Biopsies of all involved sites and refinement of genetic tests to guide treatment, if possible, are both necessary.

[Xanthogranulomatous adrenalitis : A rare and difficult differential diagnosis of adrenal gland tumors]. / Xanthogranulomatöse Adrenalitis : Seltene und schwierige Differentialdiagnose von Nebennierentumoren.

A radiologically diagnosed tumor in a 29-year-old woman with a fever of around 39 °C was operated on under the suspicion of cholecystitis or a liver abscess. A solid tumor was found in the adrenal gland and resected. The frozen section findings did not reveal a clear diagnosis of entity and assignment. Histologically, the tumor was found to consist of densely clustered large histiocyte-like cells with expression of vimentin, CD68, and CD163 as well as negativity for keratin, langerin, and SMA. We diagnosed xanthogranulomatous adrenalitis and discussed the differential diagnoses (Langerhans cell histiocytosis, Rosai-Dorfman disease, malakoplakia, Erdheim-Chester disease).

Cardiovascular manifestations of Erdheim-Chester disease: A narrative review with two cases.

Erdheim-Chester disease (ECD) is a rare 'L' (Langerhans) group histiocytic neoplasm that affects a multitude of organ systems, causing osteosclerotic bone lesions, periaortic encasement ('coated' aorta), retroperitoneal fibrosis involving kidneys and ureters ('hairy kidney'), and infiltration of the central nervous system. Cardiovascular involvement can occur in up to 70% of patients and is usually found during computed tomography/magnetic resonance imaging evaluation. When present, cardiovascular symptoms can have wide variability in presentation from asymptomatic to pericarditis, fatal cardiac tamponade, myocardial infarction, conduction abnormalities, heart failure, renal artery stenosis, and claudication. Cardiac involvement found on imaging includes right atrial pseudotumor, right atrioventricular groove infiltration, and pericardial effusions. ECD can involve the large- and medium-sized arteries, often seen as periarterial thickening (commonly coating the aorta) with stenosis/occlusion. Although more cardiovascular ECD cases have begun to be published in the literature, more data are needed on the outcomes of these patients, as well as how cardiovascular manifestations respond to treatment of ECD.

Erdheim-Chester disease with tendon and muscle involvement: Reports of a rare presentation.

Erdheim-Chester disease (ECD) is a rare histiocytic disease that affects multiple systems in the body. While it typically targets long bones, cardiovascular structures, the retroperitoneum, and the central nervous system, reports of tendon and skeletal muscle involvement are scarce. This review presents 2 cases: a case of ECD involving the left Achilles tendon and left abductor hallucis, as well as an unusual manifestation of ECD in the thigh musculature. In Case 1, studies involved a 39-year-old man who initially presented with bone and pituitary involvement. An order for 18F-FDG PET/CT imaging was placed by marked swelling in the patient's left ankle and observed soft tissue fullness on foot radiographs, which revealed a soft tissue mass involving the left Achilles tendon, which arose along the tendon-muscle junction and involved the left abductor hallucis muscle. In Case 2, studies involved a 41-year-old man who initially presented with involvement of the cardiovascular system and retroperitoneum. 18F-FDG PET/CT scan showed an infiltrative right atrial mass and hypermetabolic lesion in the left external obturator muscle, extending to the left pectineus and right quadratus femoris muscle. Involvement of the Achilles tendon and skeletal muscle involvement, including left abductor hallucis muscle and medial thigh muscles, is one of the rare manifestations of ECD. Diagnostic delays were frequent due to the condition's rarity and nonspecific multisystemic symptoms. This should be considered in patients who present with myositis, tendinopathy, and bone pain and have other unexplained multisystemic problems.

El papel de la PET/TC con 2-[18F]FDG en la enfermedad de Erdheim-Chester / The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease

Objetivo Analizar la distribución corporal de la enfermedad Erdheim-Chester (ECD) y determinar la utilidad de la 2-[18F]FDG-PET/TC frente a otras técnicas de imagen. Asimismo, evaluar la agresividad y la extensión de la enfermedad según la presencia/ausencia de mutación BRAFV600E. Material y métodos Se revisaron las 2-[18F]FDG-PET/TC de todos los pacientes diagnosticados con ECD entre 2008 y 2021: en total, 19 pacientes. Los territorios afectados se clasificaron como detectables por PET/TC o detectables solamente por otras técnicas de imagen (gammagrafía ósea, TC con contraste yodado o RM). Se realizó análisis descriptivo y correlación de la mutación BRAF con los órganos afectados y SUVmáx mediante la prueba t de Student. Resultados De los 19 pacientes (14 hombres; edad media 60,3años), 11 presentaban la mutación BRAFV600E. Se detectaron un total de 127 territorios (64 órgano-sistemas) afectados utilizando las diferentes modalidades de imagen, de los cuales 112 fueron detectados por la PET/TC y 15 territorios adicionales fueron identificados únicamente por la RM cerebral y cardiaca. La presencia de mutación BRAFV600E se asoció con mayor afectación orgánica (p<0,05), sin diferencias en el SUVmáx (p>0,05). Conclusión La 2-[18F]FDG-PET/TC es una prueba de alto rendimiento diagnóstico en pacientes con ECD, detectando la mayoría de los territorios afectados. La RM fue la única prueba de imagen con hallazgos adicionales en territorios con alta captación fisiológica de 2-[18F]FDG (cerebral y cardíaca). La presencia de mutación del BRAFV600E se correlacionó con mayor extensión de la enfermedad (AU)

Objective To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. Materials and methods The 2-[18F]FDG PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. Results Out of the 19 patients (14 males; mean age 60.3years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (P<.05) without differences in SUVmax (P>.05). Conclusion 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease (AU)

Pericardiectomy and Mechanical Mitro-Aortic Valve Replacement in a Young Patient With Erdheim-Chester Disease.

Erdheim-Chester disease is a rare histiocytosis that primarily affects the skeletal system, but cardiovascular manifestations occur in 75% of cases and are associated with a poor prognosis. Given the small number of cases, the evolution and management of the disease are uncertain. Therefore, it is important to report and share Erdheim-Chester cases. This report presents the case of a young patient with constrictive pericarditis and mitral valve regurgitation resulting from Erdheim-Chester disease.

Multisystem Erdheim-Chester disease presenting with pericardial effusion confirmed by the effusion cytology specimen.

Erdheim-Chester disease (ECD) is a rare histiocytosis characterized by the foamy CD68+CD1a- histiocytes infiltrating multiple organs and tissues. ECD might be asymptomatic or present with variable manifestations. The diagnosis of ECD requires characteristic radiological findings and pathological features. Herein, we described a 52-year-old female patient who was admitted to our hospital for recurrent pericardial effusion for two months. She has a medical history of papillary thyroid carcinoma (PTC) and underwent a total thyroidectomy two years before admission. The radiological findings suggested a potential diagnosis of ECD. Cytological analysis of the effusion cytology specimen revealed CD68+CD1a- histiocytes, confirming the ECD diagnosis. The BRAF V600E mutation was identified in the histiocytes, prompting the administration of vemurafenib, a BRAF inhibitor. After two months of standard-dose vemurafenib treatment, the disease was well controlled with pericardial effusion regression.

Dabrafenib and steroids for the treatment of Erdheim-Chester disease with extensive CNS involvement: a case report.

Erdheim-Chester disease (ECD) is an exceedingly rare non-Langerhans cell CD68+ CD1a- S100- histiocytic multi-organ disease. Diagnosis of ECD is often delayed due to non-specific radiographic findings and heterogeneous lesional tissue. Increasingly, the role of genomic alterations is being recognized for both diagnosis and treatment of ECD. More than half of ECD patients harbor the BRAFV600E mutation. Evaluation for this mutation be can falsely negative on immunohistochemical staining and confirmation with molecular analyses is recommended. We present a case of the 44 year-old male with BRAFV600E-positive ECD treated successfully with steroids followed by single-agent dabrafenib.

Erdheim-Chester disease (ECD) is an exceedingly rare type of histiocytosis (a disorder of white blood cells). The diagnosis of ECD can be challenging because tissue biopsy may not provide a definitive diagnosis. Currently, genetic mutations can be used to support both diagnosis and treatment. We present a case of the 44 year-old male with BRAF V600E -positive ECD who was treated successfully with steroids followed by dabrafenib.

A rare case report of Erdheim-Chester disease with pericardial effusion, conduction abnormalities, and atrial infiltration.

Background: Erdheim-Chester disease (ECD) is a rare multisystem disorder that primarily affects adults. It is characterized by the excessive production and accumulation of histiocytes, a type of white blood cell, within multiple tissues and organs, including the cardiovascular system. The infiltration of histiocytes can cause a range of cardiovascular symptoms, including pericardial effusion, myocardial infiltration, and heart failure, among others. Despite the potential severity of these cardiovascular manifestations, ECD is often misdiagnosed or underdiagnosed, leading to delays in appropriate treatment and poor outcomes for patients. As such, there is a pressing need for increased awareness and understanding of ECD's cardiovascular manifestations among clinicians and researchers. This article aims to highlight the importance of considering ECD as a potential underlying cause of cardiovascular complaints and to encourage further investigation into this uncommon but potentially life-threatening condition. Case summary: A 63-year-old man presented as outpatient complaining of dyspnoea on exertion during the last 3 weeks (New York Heart Association functional class III). He had also experienced a left shoulder and bilateral knee pain over the last 6 months. The patient was found to have a massive pericardial effusion associated with ECD. While pericardial effusions can have various causes, including infection, cancer, and autoimmune disorders, ECD is one potential cause of this condition. Therefore, it is important for clinicians to consider ECD in the differential diagnosis of patients presenting with unexplained pericardial effusions, particularly in the context of other systemic symptoms suggestive of ECD. We discuss about this specific aetiology and the clinical management of this uncommon condition. Discussion: Erdheim-Chester disease, a non-Langerhans cell histiocytosis, is a rare multisystem disorder. Diagnosis is challenging and should be suspected in the presence of a pericardial effusion with conduction abnormalities with indicators of a multisystem disease.

[Central nervous system disorders secondary to histiocytoses: neurodegeneration with potential for improvement].

Histiocytoses, including Langerhans cell histiocytosis (LCH) and Erdheim-Chester disease (ECD), are inflammatory myeloid tumors in which monocyte lineage cells aggregate in various organs, causing tissue damage. Most of these tumors harbor oncogenic mutations in mitogen-activated protein kinase (MAPK) pathway genes, typified by BRAFV600E. Some patients with LCH develop bilateral symmetrical cerebellar lesions and brain atrophy several years after diagnosis when the initial symptoms disappear, leading to cerebellar ataxia and higher cerebral dysfunction. A similar neurological disorder has also been reported in ECD. This neurological disorder can be improved with MAPK inhibitors. When patients with this neurological disorder are identified among neurodegeneration of unknown etiology or histiocytosis patients and treated early with MAPK inhibitors, the disorder can be reversible.

A Rare Case of Erdheim Chester's Disease Presenting As Atypical Breast Involvement.

Erdheim-Chester disease (ECD) is a rare multisystem disorder characterized by mitogen-activated protein kinase (MAPK) pathway mutations. Herein, we present a unique case of ECD in a 79-year-old female with predominant breast nodules. Comprehensive imaging and histopathological evaluations confirmed the diagnosis. Mammography and ultrasonography revealed multiple hyperdense circumscribed nodules with coalescing masses and blurred margins. Core biopsy revealed infiltrating foamy CD68+ and CD1a+ histiocytes. Because the tumor was negative for the BRAF V600E mutation, treatment with interferon-α was initiated. This case highlights the diagnostic challenges associated with ECD, the rarity of breast involvement, and the importance of considering ECD in the differential diagnosis of atypical breast lesions. Comprehensive imaging, histopathology, and genetic testing are essential for accurate diagnosis and treatment decision-making in ECD. Further research and awareness are required to improve recognition and management of this rare disease.

The role of 2-[18F]FDG PET/CT in Erdheim-Chester disease.

OBJECTIVE: To analyze the body distribution of Erdheim-Chester disease (ECD) and determine the utility of 2-[18 F]FDG PET/CT compared to other imaging techniques. Additionally, to assess the aggressiveness and extent of the disease based on the presence/absence of the BRAFV600E mutation. MATERIALS AND METHODS: The 2-[18F]FDG-PET/CT scans of all patients diagnosed with ECD between 2008 and 2021 were reviewed, including 19 patients. The affected territories were classified as detectable by PET/CT or detectable only by other imaging techniques (bone scintigraphy, contrast-enhanced CT, or MRI). Descriptive analysis and correlation of the BRAF mutation with the affected organs and maximum SUV were performed using the Student's t-test. RESULTS: Out of the 19 patients (14 males; mean age 60.3 years), 11 had the BRAFV600E mutation. A total of 127 territories (64 organ-systems) affected were identified using different imaging modalities, of which 112 were detected by PET/CT, and an additional 15 territories were solely identified by cerebral and cardiac MRI. The presence of BRAFV600E mutation was associated with greater organ involvement (p < 0.05) without differences in SUVmax (p > 0.05). CONCLUSION: 2-[18F]FDG PET/CT is a highly effective diagnostic tool in patients with ECD, detecting the majority of affected territories. MRI was the only imaging modality with additional findings in territories showing high physiological uptake of 2-[18F]FDG (cerebral and cardiac). The presence of the BRAFV600E mutation correlated with a higher extent of the disease.

Erdheim-Chester disease of brain parenchyma without any systemic involvement: A case report and review of literature.

Erdheim-Chester disease is a non-Langerhans cell histiocytosis syndrome characterised by histiocytic infiltration of different organs and systems in the body. Erdheim-Chester disease with isolated central nervous system (CNS) involvement causes diagnostic difficulties due to the absence of systemic findings and may result in misdiagnosis and inaccurate treatment choices. The case discussed in this report exemplifies how challenging it is to diagnose Erdheim-Chester disease with isolated CNS involvement. This case, which presented with progressive pyramidocerebellar syndrome, was clinically and radiologically resistant to all immunosuppressive and immunomodulatory treatments administered. The presence of false negative results in repeated histopathological investigations and the absence of evidence for systemic disease hindered the diagnosis and treatment work-up. In this study, we reviewed and discussed the prominent features of the presented case in light of the relevant literature.