Erdheim–Chester disease

Multisystem Radiologic Manifestations of Erdheim-Chester Disease

Erdheim-Chester Disease is a rare form of multiorgan non-Langerhans' cell histiocytosis that affects individuals between the ages of 50 and 70 with an equal distribution among males and females. It is associated with significant morbidity and mortality that is mostly due to infiltration of critical organs. Some of the sites that Erdheim-Chester Disease affects include the skeletal system, central nervous system, cardiovascular system, lungs, kidneys (retroperitoneum), and skin. The most common presenting symptom of Erdheim-Chester Disease is bone pain although a large majority of patients are diagnosed incidentally during a workup for a different disease process. Diagnosing Erdheim-Chester Disease is challenging due its rarity and mimicry to other infiltrative processes. Therefore, a multimodality diagnostic approach is employed with imaging being at the forefront. As of date, a comprehensive radiologic review of the manifestations of Erdheim-Chester Disease has rarely been reported. Here we present radiologic findings of an individual suffering from Erdheim-Chester Disease.

[Erdheim-Chester disease (ECD), an inflammatory myeloid neoplasia]

In a compatible clinico-radiological setting, the diagnosis of Erdheim-Chester disease (ECD) involves the analysis of histiocytes in tissue biopsies: they are typically foamy and CD68+ CD1a, whereas in Langerhans cell histiocytosis (LCH) they are CD68+ CD1a+. Overlap forms of histiocytoses are frequent. Technetium bone scintigraphy showing nearly constant tracer uptake by the long bones is highly suggestive of ECD and a 'hairy kidney' appearance on abdominal CT scan is observed in more than half ECD cases. CNS involvement is a strong prognostic factor and an independent predictor of death in cases of ECD. Optimal initial therapy for ECD appears to be administration of IFN-α (and/or pegylated IFN-α) and prolonged treatment significantly improves survival; however, tolerance may be poor. Best alternative therapies are anakinra, mainly effective for mild forms of the disease, infliximab, and sirolimus. Cases of ECD present with strong systemic immune activation, involving IFN-α, IL-1/IL1-RA, IL-6, IL-12, and MCP-1, consistent with the systemic immune Th-1-oriented disturbance associated with the disease. Between 57 and 75 % of ECD patients carry the BRAF^V600E mutation, an activating mutation of the proto-oncogene BRAF. More than 50 cases harboring BRAF mutation and with severe multisystemic and refractory ECD (sometimes associated with LCH) have been treated worldwide with vemurafenib, a BRAF inhibitor that proved to be very beneficial. Other recurrent mutations of the MAPK (NRAS, MAP2K1) and PIK3 pathways (PIK3CA) have been found among ECD patients. As recurrent mutations in the MAPK pathway are found in ECD and LCH on a background of chronic inflammation, we believe that both conditions should be redefined as an inflammatory myeloid neoplasia.

Plasma Chromogranin A as a marker of cardiovascular involvement in Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis (LCH) characterized by tissue infiltration with CD68(+) foamy histiocytes. TNF-related chronic inflammation and mutations in the MAP kinase signaling pathway in histiocytes are recognized as the two major pathogenic events. Among pleomorphic clinical manifestations, cardiovascular involvement is frequent and prognostically relevant. Evaluation of ECD clinical course and response to treatment is, however, still challenging. Taking advantage of the two largest cohorts of ECD patients worldwide, we investigated the relevance and the potential of circulating Chromogranin A (CgA), a pro-hormone involved in cardiovascular homeostasis and inflammation, as a biomarker of response to therapy in ECD. Consistent with other TNF-related inflammatory diseases, we found that not only TNF-α and soluble TNF-Receptors (sTNF-Rs), but also CgA plasma levels were significantly increased in ECD patients compared to controls. CgA, but not sTNF-Rs, discriminated cardiovascular involvement in ECD patients and correlated with pro-Brain Natriuretic Peptide (pro-BNP). In a single case, where a cardiac biopsy was available, CgA was found expressed by cardiomyocytes but not by infiltrating histiocytes. In four ECD patients, where serial determination of these parameters was obtained, the kinetics of sTNF-Rs and CgA paralleled response to therapy with anti-cytokine inhibitors; specifically, sTNF-Rs overlapped TNF-associated inflammation, while CgA, together with pro-BNP, closely mirrored response of cardiac disease. Our data indicate that both sTNF-Rs and CgA are linked to ECD pathophysiology. Moreover, CgA, in concert with pro-BNP, can be further exploited to fulfill the unmet clinical need of non-invasive reliable biomarkers of cardiac disease in these patients.

Erdheim-Chester Disease as a Mimic of IgG4-Related Disease: A Case Report and a Review of a Single-Center Cohort

Immunoglobulin-G4 (IgG4)-related disease (IgG4RD) is a fibro-inflammatory disorder characterized by tissue-infiltrating IgG4 plasma cells, and, often, high serum IgG4. Several autoimmune, infectious, or proliferative conditions mimic IgG4RD. Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis, characterized by foamy histiocytic infiltration, fibrosis, and chronic inflammation. ECD and IgG4RD manifestations may overlap.A patient presented with huge fibrous retroperitoneal masses causing compression on neighboring structures; the case posed the challenge of the differential diagnosis between IgG4RD and ECD mainly because of a prominent serum and tissue IgG4 response.Retroperitoneal biopsy led to the diagnosis of ECD; the V600E BRAF mutation was found. Treatment with the BRAF inhibitor vemurafenib was started.Treatment failed to induce mass regression and the patient died after 3 months of therapy. Prompted by this case, we examined serum and tissue IgG4 in a series of 15 ECD patients evaluated at our center, and found that approximately one-fourth of the cases have increased IgG4 in the serum and often in the tissue.The differential diagnosis between IgG4RD and ECD can be challenging, as some ECD patients have prominent IgG4 responses. This suggests the possibility of common pathogenic mechanisms between ECD and IgG4RD.

Erdheim-Chester disease: description of eight cases

Erdheim-Chester disease, although rare, has a wide range of manifestations. It is characterized by the xanthomatous infiltration of tissues by spumous histiocytes, surrounded by fibrosis. The symptoms can vary from bone pain, diabetes insipidus, exophthalmos, xanthelasmas, cardiovascular involvement, bilateral adrenal enlargement, renal impairment, testis infiltration, interstitial lung disease to retroperitoneal fibrosis with perirenal and/or ureteral obstruction. We present eight cases, four of them with only breast involvement and the others with bone, cardiovascular, central nervous system, and renal involvement. All showed infiltrates of histiocytes and fibrosis on microscopic evaluation and positive CD68 and negative CD1a on immunohistochemical stains.

Langerhans cell histiocytosis: a comprehensive review

Langerhans cell histiocytosis (LCH) is currently regarded as a myeloid neoplasm, with remarkably broad clinical spectrum, ranging from isolated skin or bone lesions to a disseminated disease that can involve nearly any organ. LCH is generally regarded as a sporadic disease that occurs predominantly in the paediatric population. The diagnosis of LCH is confirmed by immunohistochemistry (IHC) by demonstrating the presence of dendritic cell markers such as S100 protein, in addition to CD1a and langerin. Contrary to previous beliefs, recent literature reveals that the pathogenesis of LCH might involve a clonal process implicating BRAF c.1799T>A (p.Val600Glu) and other mutations [(600DLAT) B-RAF and (T599A) B-RAF, somatic MAP2K1 mutations].Through this review article, we have summarised the latest understanding of the biological and salient histological characteristics of LCH and its potential morphological mimics.

Adult-Onset Asthma and Periocular Xanthogranulomas Associated with Systemic IgG4-Related Disease

PURPOSE

The aim of this study was to report a case of Adult-Onset Asthma with Periocular Xanthogranulomas (AAPOX) associated with systemic IgG4-related disease (IgG4-RD).

OBSERVATIONS

A 57-year-old man presented with bilateral periorbital swelling for 1 year. Histopathology of a left orbital biopsy showed fibro vascular connective tissue inundated with foamy, lipid-laden histiocytes and touton giant cells with lymphocytic inflammation. Additional stains revealed CD68 positivity, and S100 negativity. The IgG and IgG4 stained slides showed increased IgG4 positive plasma cells but did not meet the criteria for IgG4-related orbital disease. His IgG4 serology was elevated, and IgG4 staining of his tissue previously diagnosed as autoimmune sclerosing pancreatitis was found to meet the criteria for IgG4-RD.

CONCLUSIONS AND IMPORTANCE

AAPOX can be associated with systemic IgG4-RD.

Uncommon histiocytic disorders: Rosai–Dorfman, juvenile xanthogranuloma, and Erdheim–Chester disease

Rosai–Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and Erdheim–Chester disease (ECD) are non-Langerhans cell (non-LCH) disorders arising from either a dendritic or a macrophage cell. RDD is a benign disorder that presents with massive lymphadenopathy, but can have extranodal involvement. In most cases, RDD is self-limited and observation is the standard approach. Treatment is restricted to patients with life-threatening, multiple-relapsing, or autoimmune-associated disease. JXG is a pediatric histiocytosis characterized by xanthomatous skin lesions that usually resolve spontaneously. In a minority of cases, systemic disease can occur and can be life threatening. Juvenile myelomonocytic leukemia (JMML), as well as germline mutations in NF1 and NF2, have been reported in children with JXG. Recent whole-exome sequencing of JXG cases did not show the BRAF-V600E mutation, although 1 patient had PI3KCD mutation. ECD is an adult histiocytosis characterized by symmetrical long bone involvement, cardiovascular infiltration, a hairy kidney, and retroperitoneal fibrosis. Central nervous system involvement is a poor prognostic factor. Interferon-α is the standard as front-line therapy, although cladribine and anakinra can be effective in a few refractory cases. More than one-half of ECD patients carry the BRAF-V600E mutation. Currently, >40 patients worldwide with multisystemic, refractory BRAF-V600E+ ECD have been treated with vemurafenib, a BRAF inhibitor, which was found to be highly effective. Other recurrent mutations of the MAP kinase and PI3K pathways have been described in ECD. These discoveries may redefine ECD, JXG, and LCH as inflammatory myeloid neoplasms, which may lead to new targeted therapies.

Case 224: Cardiac Involvement in Erdheim-Chester Disease

History A 61-year-old man with no relevant medical history was admitted to the emergency department with symptoms of congestive heart failure and a 1-week history of chest pain, progressive dyspnea, abdominal swelling, bipedal edema, and anorexia. Laboratory test results, including complete blood count and electrolyte, creatinine, creatine phosphokinase, and troponin T levels were normal. Electrocardiographic findings were unremarkable. Initial chest radiography showed an enlarged heart with bilateral pleural effusion. Transthoracic echocardiography revealed an irregular right atrial mass and moderate to severe pericardial effusion. The patient subsequently underwent computed tomography (CT) of the chest, abdomen, and pelvis followed by cardiac magnetic resonance (MR) imaging for further evaluation of the atrial mass. Because of the suspected diagnosis, conventional radiography of the skeleton was performed.

BRAFV600E-mutation is invariably present and associated to oncogene-induced senescence in Erdheim-Chester disease

OBJECTIVES

Erdheim-Chester disease (ECD) is a rare form of histiocytosis characterised by uncontrolled chronic inflammation. The oncogenic BRAF(V600E) mutation has been reported in biopsies in 19 out of 37 patients with ECD from the largest published cohort, but never found in the patients' peripheral blood. Also, the role of the mutation in the pathogenesis of the disease has not been elucidated yet. BRAF(V600E) has been associated with oncogene-induced senescence (OIS), a protective mechanism against oncogenic events, characterised by the induction of proinflammatory pathways.

METHODS

We verified the BRAF status in biopsies and peripheral blood from 18 patients with ECD from our cohort and matched controls by means of immunohistochemistry and of an ultrasensitive assay, based on the combination of a locked nucleic acid PCR and pyrosequencing. Droplet digital PCR was used to confirm the findings. We also evaluated the presence of senescence markers in ECD histiocytes.

RESULTS

BRAF(V600E) mutation was present in all the biopsy and peripheral blood samples from patients with ECD and in none of the controls. ECD histiocytes and a fraction of circulating monocytes from patients with ECD showed signs of a constitutive activation of the MAPK pathway. Moreover, BRAF-mutated histiocytes expressed markers of OIS.

CONCLUSIONS

The oncogenic BRAF(V600E) mutation is present in biopsies and in the peripheral blood from all patients with ECD who were evaluated and is associated with OIS. These findings have significant implications for the pathogenesis, diagnosis and treatment of ECD.

Sirolimus plus prednisone for Erdheim-Chester disease: an open-label trial

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis, to whose pathogenesis neoplastic and immune-mediated mechanisms contribute. Mammalian target of rapamycin (mTOR)-inhibitors have antiproliferative and immunosuppressive properties. We tested in this study, the efficacy and safety of the mTOR-inhibitor sirolimus (SRL) plus prednisone (PDN) in patients with ECD. PDN was given initially at 0.75 mg/kg per day, tapered to 5 to 2.5 mg per day by month 6. Target SRL blood levels were 8 to 12 ng/mL. Treatment was continued for at least 24 months in patients who showed disease stabilization or improvement. Ten patients were enrolled; 8 achieved stable disease or objective responses, whereas 2 had disease progression. Responses were mainly observed at the following sites: retroperitoneum in 5/8 patients (62.5%), cardiovascular in 3/4 (75%), bone in 3/9 (33.3%), and central nervous system (CNS) in 1/3 (33.3%). The median follow-up was 29 months (interquartile range, 16.5-74.5); 2 patients died of progressive CNS disease and small-cell lung cancer, respectively. Treatment-related toxicity was mild. Using immunohistochemistry and immunofluorescence on ECD biopsies, we detected expression in foamy histiocytes of the phosphorylated forms of mTOR and of its downstream kinase p70S6K, which indicated mTOR pathway activation. In conclusion, SRL and PDN often induce objective responses or disease stabilization and may represent a valid treatment of ECD. The trial is registered at the Australia-New Zealand Clinical Trial Registry as #ACTRN12613001321730.

Erdheim-Chester disease mimicking an intracranial trigeminal schwannoma: case report

Erdheim-Chester disease (ECD) is non-Langerhans histiocytosis that can affect multiple organ systems. It usually affects middle-aged patients, and only a few reports of ECD in children appear in the literature. Central nervous system involvement is a common feature that usually occurs as infiltration of the hypothalamus-pituitary axis, cerebellum, and/or brainstem. Meningeal involvement occurs less commonly. In this article, the authors discuss a rare pediatric case of ECD presenting as an infiltrative mass of the trigeminal nerve and resembling the clinical and imaging features of a trigeminal schwannoma.

Excellent response of intramedullary Erdheim-Chester disease to vemurafenib: a case report

Background

Erdheim-Chester disease is a rare histiocytosis characterized by multi-systemic organ involvement. Immune-modulating agents such as interferon-alpha have limited success and the disorder is progressive and causes high morbidity and mortality. Treatment with the BRAF-inhibitor vemurafenib has recently produced substantial improvement in three patients with Erdheim-Chester disease expressing the p. V600E BRAF mutation. The disorder commonly affects the central nervous system and it is not yet known whether vemurafenib can reverse intra-axial infiltration and the resulting neurological impairment.

Case presentation

In this work, we report for the first time an excellent clinical response to vemurafenib in a Norwegian patient with debilitating progressive spastic paraparesis due to intra-axial infiltration of the thoracic spinal cord. The patient had been unresponsive to interferon-alpha. Low dose vemurafenib (720 mg daily) for a period of three months resulted in significant tumor shrinkage by >60% and regression of contrast enhancement and fluorodeoxyglucose uptake on positron-emission tomography. The patient’s spastic paraparesis and gait function improved dramatically. She currently walks unaided and reports a substantially improved quality of life.

Conclusion

Our findings show that vemurafenib therapy, even at low doses, can be effective for the treatment of intra-axial central nervous system involvement in BRAF-positive Erdheim-Chester disease.

The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes that stain positively for CD68 marker but not express CD1a and S100 proteins. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. Multisystemic involvement leads to a wide variety of clinical manifestations that results in a poor prognosis although recent advances in treatment. We present the clinical, nuclear medicine findings and therapeutic aspects of a serie of 6 patients with histopathological diagnosis of ECD, who have undergone both bone scintigraphy (BS) and 18F-fluorodeoxyglucose (18FDG)-PET/CT scans in our institution. A complementary 18F-fluorodopa (18FDOPA)-PET/CT was performed in one case. Three different presentations of the disease were observed in our casuistic: most indolent form was a cutaneous confined disease, presented in only one patient. Multifocal involvement with central nervous system (CNS) preservation was observed in two patients. Most aggressive form consisted in a systemic involvement with CNS infiltration, presented in three patients. In our experience neurological involvement, among one case with isolate pituitary infiltration, was associated with mortality in all cases. 18FDG-PET/CT and BS were particularly useful in despite systemic involvement; locate the site for biopsy and the treatment response evaluation. By our knowledge, 18FDOPA-PET/CT not seems useful in the initial staging of ECD. A baseline 18FDG-PET/CT and BS may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically 18FDG-PET/CT must be performed in the follow up to evaluate treatment response.

Evidence of BRAF V600E in indeterminate cell tumor and interdigitating dendritic cell sarcoma

BRAF V600E mutations have been reported in several histiocytic and dendritic cell neoplasms. In this case series, we report BRAF V600E-positive histiocytic and dendritic cell neoplasms in association with lymphomas and lymphoid proliferations. This is a review of cases with immunohistochemistry for BRAF V600E, with additional immunohistochemistry to categorize tumors. We report the first case of BRAF V600E-positive indeterminate cell tumor in association with angioimmunoblastic T-cell lymphoma. We also report a case of BRAF V600E-positive interdigitating dendritic cell sarcoma in a patient with positive B-cell polymerase chain reaction. It is unclear if these neoplasms developed as transdifferentiation of lymphoid neoplasms or if they developed independently. These cases illustrate the expanding spectrum of BRAF V600E-positive histiocytic and dendritic cell tumors and suggest that attention should be paid to lymphomas for possible coincident presentation of these disorders.

Complete remission of critical neurohistiocytosis by vemurafenib

Objective:

To describe a patient with life-threatening brainstem neurohistiocytosis who recovered completely upon targeted treatment with the V600E mutation-specific BRAF inhibitor vemurafenib.

Methods:

We report clinical, histiologic, genetic, and sequential imaging findings, including fluorodeoxyglucose (FDG)-PET, over a follow-up period of 11 months.

Results:

The patient presented with central hyperventilation, skeletal and perirenal Erdheim-Chester disease, and cutaneous Langerhans cell histiocytosis. A BRAF V600E hotspot mutation was detected in all afflicted tissues. Therapy with vemurafenib led to complete and stable clinical remission of CNS lesions and systemic disease that could be demonstrated by brain MRI and whole-body FDG-PET.

Conclusions:

Neurologic involvement in Erdheim-Chester disease usually confers a poor prognosis. In this patient, vemurafenib was well-tolerated and highly efficacious for severe brainstem involvement in Erdheim-Chester disease with overlapping Langerhans cell histiocytosis. This case illustrates the heterogeneous phenotypic spectrum of neurohistiocytosis and underscores the importance of genetic testing.

Classification of evidence:

This article provides Class IV evidence. This is a single observational study without controls.

Erdheim-Chester disease: a systematic review

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans-cell histiocytosis, associated in more than 50% of cases to BRAF(V600E) mutations in early multipotent myelomonocytic precursors or in tissue-resident histiocytes. It encompasses a spectrum of disorders ranging from asymptomatic bone lesions to multisystemic, life-threatening variants. We reviewed all published reports of histologically-confirmed ECD and explored clinical, radiological, prognostic and therapeutic characteristics in a population of 448 patients, including a unique patient from our Department. To find a clinically relevant signature defining differentiated prognostic profiles, the patients' disease features were compared in relation to their CNS involvement that occurred in 56% of the entire population. Diabetes insipidus, visual disturbances, pyramidal and extra-pyramidal syndromes were the most recurrent neurological signs, whereas concomitant pituitary involvement, retro-orbital masses and axial lesions in the presence of symmetric bilateral osteosclerosis of long bones depicted the typical ECD clinical picture. Patients with CNS infiltration showed a lower occurrence of heart involvement and a higher incidence of bone, skin, retro-peritoneal, lung, aortic and renal infiltration. No difference in the therapeutic algorithm was found after stratification for CNS involvement. A better understanding of the disease pathogenesis, including BRAF deregulation, in keeping with improved prognostic criteria, will provide novel suggestions for the management of ECD.

Uncommon histiocytic disorders: Rosai-Dorfman, juvenile xanthogranuloma, and Erdheim-Chester disease

Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), and Erdheim-Chester disease (ECD) are non-Langerhans cell (non-LCH) disorders arising from either a dendritic or a macrophage cell. RDD is a benign disorder that presents with massive lymphadenopathy, but can have extranodal involvement. In most cases, RDD is self-limited and observation is the standard approach. Treatment is restricted to patients with life-threatening, multiple-relapsing, or autoimmune-associated disease. JXG is a pediatric histiocytosis characterized by xanthomatous skin lesions that usually resolve spontaneously. In a minority of cases, systemic disease can occur and can be life threatening. Juvenile myelomonocytic leukemia (JMML), as well as germline mutations in NF1 and NF2, have been reported in children with JXG. Recent whole-exome sequencing of JXG cases did not show the BRAF-V600E mutation, although 1 patient had PI3KCD mutation. ECD is an adult histiocytosis characterized by symmetrical long bone involvement, cardiovascular infiltration, a hairy kidney, and retroperitoneal fibrosis. Central nervous system involvement is a poor prognostic factor. Interferon-α is the standard as front-line therapy, although cladribine and anakinra can be effective in a few refractory cases. More than one-half of ECD patients carry the BRAF-V600E mutation. Currently, >40 patients worldwide with multisystemic, refractory BRAF-V600E(+) ECD have been treated with vemurafenib, a BRAF inhibitor, which was found to be highly effective. Other recurrent mutations of the MAP kinase and PI3K pathways have been described in ECD. These discoveries may redefine ECD, JXG, and LCH as inflammatory myeloid neoplasms, which may lead to new targeted therapies.

Intrapelvic Bulky Tumor as an Unusual Presentation of Erdheim-Chester Disease

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis, which is known to affect various organs; however, there have been no reports of its intrapelvic involvement. We herein describe the case of 69-year-old man who died of a rapidly-growing intrapelvic tumor, which was finally diagnosed as ECD at autopsy. Immunohistochemically, the tumor cells were positive for CD68 and BRAF V600E, and negative for CD1a. Since BRAF V600E has recently been reported to be specific to ECD, it can be a useful biomarker for diagnosis, especially in atypical cases.

Clinical considerations and key issues in the management of patients with Erdheim-Chester Disease: a seven case series

BACKGROUND

Erdheim-Chester Disease (ECD), a non Langerhans' cell histiocytosis of orphan nature and propensity for multi-systemic presentations, comprises an intricate medical challenge in terms of diagnosis, treatment and complication management.

OBJECTIVES

The objectives are to report the clinical, radiological and pathological characteristics, as well as cardinal therapeutic approaches to ECD patients and to provide clinical analyses of the medical chronicles of these complex patients.

METHODS

Patients with biopsy proven ECD were audited by a multi-disciplinary team of specialists who formed a coherent timeline of all the substantial clinical events in the evolution of their patients' illness.

RESULTS

Seven patients (five men, two women) were recruited to the study. The median age at presentation was 53 years (range: 39 to 62 years). The median follow-up time was 36 months (range: 1 to 72 months). Notable ECD involvement sites included the skeleton (seven), pituitary gland (seven), retroperitoneum (five), central nervous system (four), skin (four), lungs and pleura (four), orbits (three), heart and great vessels (three) and retinae (one). Prominent signs and symptoms were fever (seven), polyuria and polydipsia (six), ataxia and dysarthria (four), bone pain (four), exophthalmos (three), renovascular hypertension (one) and dyspnea (one). The V600E BRAF mutation was verified in three of six patients tested. Interferon-α treatment was beneficial in three of six patients treated. Vemurafenib yielded dramatic neurological improvement in a BRAF mutated patient. Infliximab facilitated pericardial effusion volume reduction. Cladribine improved cerebral blood flow originally compromised by perivenous lesions.

CONCLUSIONS

ECD is a complex, multi-systemic, clonal entity coalescing both neoplastic and inflammatory elements and strongly dependent on impaired RAS/RAF/MEK/ERK signaling.

[A man in his forties with swelling in both orbits]

Erdheim-Chester disease. A multi-disiplinary challenge. The histiocytoses are a diverse, but rare group of disorders with symptoms affecting many organs, varying from self-limiting, localised lesions to disseminated multi-organ disease. The diagnostic challenges are illustrated and discussed in the following case.

CASE REPORT

A man in his forties was admitted to hospital due to pain in his right eye and visual disturbances. MRI imaging detected a mass in his right orbit and a minor mass in his left orbit. The histological results of the mass in his right orbit revealed an inflammatory process with lymphocytes and macrophages and no sign of vasculitis, infection or malignancy. The diagnosis pseudotumor orbita was made and treatment with corticosteroids was initiated. He did not respond to corticosteroids or radiotherapy and increasing symptoms necessitated rehospitalisation. Further tests disclosed a multisystem disease which affected the aorta, skeleton, lung, heart and kidney. The biopsy was reconsidered and the disease was classified as a histiocytosis with CD68 positive and CD1a negative cells. The diagnosis Erdheim-Chester was given, about 14 months after the initial hospitalisation. Treatment with interferon α was started.

Erdheim-Chester disease: from palliative care to targeted treatment

Erdheim–Chester disease (ECD) is a life-threatening multi-systemic non-Langerhans histiocytosis with cardiovascular complications as the leading cause of death. ECD affects the kidneys in up to 30% of cases, with fibrotic tissue deposition in the perirenal fat and renal hilum. Diagnosis is usually based on histological analysis of the pathologic tissue, which typically shows xanthogranulomatous infiltrates of foamy CD68+/CD1a- histiocytes surrounded by fibrosis. A consistent percentage of patients affected by ECD develop renal failure and hypertension as a consequence of renal artery stenosis and hydronephrosis. These conditions have been generally treated with the placement of stents and nephrostomies that frequently led to disappointing outcomes. Before the introduction of interferon-alpha (IFNα) treatment, the mortality rate was as high as 57% in the long term. Recent studies have granted new insights into the pathogenesis of ECD, which seems to bear a dual component of clonal and inflammatory disease. These advances led to use specific therapies targeting either the oncogenes (BRAF^V600E) or the effectors of the immune response implicated in ECD (IL-1, TNFα). Drugs such as anakinra (recombinant human IL-1 receptor antagonist), infliximab (monoclonal antibody against TNFα) and vemurafenib (inhibitor of mutant BRAF) showed promising results in small single-centre series. Although larger trials will be needed to address the impact of these drugs on ECD prognosis and to select the most effective treatment, targeted therapies hold the premises to drastically change the outcome of this condition.

Erdheim chester - A rare disease with unique endoscopic features

Erdheim-Chester disease (ECD) is a rare inflammatory syndrome in which systemic infiltration of non-Langerhans cell histiocytes occurs in different sites. Both the etiology and pathophysiology of ECD are unknown, but CD68 positive CD 1a/S100 negative cells are characteristic. The presentation of ECD differs according to the involved organs. This case report describes a patient with ECD and the gastrointestinal manifestations and unique endoscopic appearance as seen in gastroscopy and colonoscopy with histological proof of histiocyte infiltration of the lamina propria. The clinical and endoscopic findings of this unique case, to our knowledge, were never described before, so were the features of the gastrointestinal involvement in this disease.

Erdheim-Chester disease: characteristics and management

Erdheim-Chester disease is a rare CD68(+), CD1a(-) non-Langerhans cell histiocytosis with multiorgan involvement. The etiology of Erdheim-Chester disease is unclear; there are no known associated infectious or hereditary genetic abnormalities. However, somatic BRAF mutations have recently been identified in these patients. Historically, the literature regarding the management of Erdheim-Chester disease consisted of case reports and small case series with anecdotal therapeutic responses to agents including, but not limited to, cytotoxic chemotherapy, bone marrow transplantation, cladribine, corticosteroids, IFN-α, the BCR-ABL/KIT inhibitor imatinib mesylate, the IL-1 receptor antagonist anakinra, the TNF-inhibitor infliximab, and recently the BRAF inhibitor vemurafenib. We performed a search of the literature using PubMed with the terms Erdheim Chester disease, without date limitations, including case reports, case series, original articles, and previous review articles. In the absence of large-scale studies, experience-based management prevails. The present review details our approach to the management of patients with Erdheim-Chester disease.

Erdheim-Chester disease: an unusual presentation of an uncommon disease

Erdheim-Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis with classic radiographic findings of patchy or diffuse osteosclerosis predominantly involving the long bones in a bilaterally symmetrical pattern. A 49-year-old woman presented with diffuse lymphadenopathy, painful skin lesions, and constitutional symptoms. Recent history was significant for a nontraumatic fracture of the tibia 3 weeks prior to admission. Physical examination and laboratory studies were notable for lower extremity pain and swelling, nodular lesions on the skin, and normocytic, normochromic anemia. Plain radiographs showed a lytic pattern of destruction with a superimposed fracture in the left proximal tibia. MRI showed focal bone marrow replacement extending from the subchondral bone to the tibial diaphysis. Excisional lymph node and skin biopsies of the lesions demonstrated a CD-68 positive, S-100 variable, and CD1a-negative histiocytic cell proliferation filling the dermis and completely replacing the sampled lymph node with an accompanying chronic inflammatory infiltrate and fibrosis, pathognomonic for ECD. We report an unusual case of ECD presenting initially as diffuse, painful lymphadenopathy, and subsequently demonstrating a lytic lesion of the tibia underlying a nontraumatic fracture.

Consensus guidelines for the diagnosis and clinical management of Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare, non-Langerhans histiocytosis. Recent findings suggest that ECD is a clonal disorder, marked by recurrent BRAFV600E mutations in >50% of patients, in which chronic uncontrolled inflammation is an important mediator of disease pathogenesis. Although ∼500 to 550 cases have been described in the literature to date, increased physician awareness has driven a dramatic increase in ECD diagnoses over the last decade. ECD frequently involves multiple organ systems and has historically lacked effective therapies. Given the protean clinical manifestations and the lack of a consensus-derived approach for the management of ECD, we provide here the first multidisciplinary consensus guidelines for the clinical management of ECD. These recommendations were outlined at the First International Medical Symposium for ECD, comprised of a comprehensive group of international academicians with expertise in the pathophysiology and therapy of ECD. Detailed recommendations on the initial clinical, laboratory, and radiographic assessment of ECD patients are presented in addition to treatment recommendations based on critical appraisal of the literature and clinical experience. These formalized consensus descriptions will hopefully facilitate ongoing and future research efforts in this disorder.

Erdheim-Chester disease and pituitary involvement: a unique case and the literature

An early thirties man diagnosed with Erdheim-Chester disease (ECD) was simultaneously disclosed to have hypogonadotropic hypogonadism, central adrenal insufficiency, and GH deficiency in addition to central diabetes insipidus (CDI). Pituitary magnetic resonance imaging (MRI) showed swelling in the stalk, enlargement of the anterior lobe with delayed enhancement, and loss of high intensity of the posterior lobe on T1-weighted images, suggesting of pituitary involvement of ECD. Three months after starting treatment with interferon α and zoledronic acid, polyuria and polydipsia were ameliorated without DDAVP, accompanied with improvement of MRI. Simultaneously technetium-99m bone scintigraphy showed improvement, accompanied with a relief of bone pain and high fever. In contrast, he developed secondary hypothyroidism with slight enlargement of anterior pituitary gland without relapse of CDI, suggesting of different responses to treatment with interferon α between anterior pituitary lobe and posterior one. So far he continues to be replaced with deficient hormone replacement therapy. As for bone pain, it remains to be controlled with the decreased levels of bone resorption marker with decreased abnormal uptake in bone scintigraphy although zoledronic acid was discontinued for osteonecrosis of the jaw. For four years, he has not showed new involvement at other organs besides bones and the pituitary. While CDI is known to be very common in ECD, improvement of CDI has been reported in a few cases. Other endocrine manifestations, especially with detailed endocrine status, have been also reported in limited cases. Thus we report this case and review the literature.

The multifaceted clinical presentations and manifestations of Erdheim-Chester disease: comprehensive review of the literature and of 10 new cases

OBJECTIVES

Erdheim-Chester disease (ECD) is a rare inflammatory disorder characterised by organ infiltration by non-Langerhans' histiocytes. Although rare, ECD is clearly an overlooked diagnosis. No data specifically addressing the most frequent presentations of ECD at the time of onset in a large cohort of patients are currently available.

METHODS

We reviewed all the published cases in the English literature of histologically-confirmed ECD. We excluded reports in which data regarding onset and diagnosis were not univocal, as well as repeated reports of the same case(s). We also included in the analysis 10 new unpublished patients from our cohort. We analysed the disease presentation with particular regard to the manifestations that induced patients to seek medical attention and their subsequent evolution.

RESULTS

In the cumulative cohort of 259 cases, ECD predominantly presented with skeletal symptoms, diabetes insipidus, neurological and constitutional symptoms. Diabetes insipidus and constitutional symptoms, if not present at onset, seemed to only seldom develop. There were differences in ECD presentation and course among different age groups of patients.

CONCLUSIONS

Physicians should be aware of the extraordinarily heterogeneous clinical presentations and manifestations of ECD in order to include ECD in the differential diagnosis of several conditions.

Erdheim-Chester Disease: a comprehensive review of the literature

Erdheim-Chester Disease (ECD) is a rare form of non Langerhans' cell histiocytosis. Individuals affected by this disease are typically adults between their 5th and 7th decades of life. Males and females are almost equally affected. The multi systemic form of ECD is associated with significant morbidity, which may arise due to histiocytic infiltration of critical organ systems. Among the more common sites of involvement are the skeleton, central nervous system, cardiovascular system, lungs, kidneys (retroperitoneum) and skin. The most common presenting symptom of ECD is bone pain. The etiology of ECD is unknown yet thought to be associated with an intense TH1 immune response. It may also be associated with the V600E BRAF mutation, as described in as many as half of the patients in recent studies. Bilateral symmetric increased tracer uptake on ^99mTc bone scintigraphy affecting the periarticular regions of the long bones is highly suggestive of ECD. However, definite diagnosis of ECD is established only once CD68(+), CD1a(−) histiocytes are identified within a biopsy specimen. At present, this obscure ailment embodies numerous challenges to medical science. Given its rarity, it is diagnostically elusive and requires a high level of clinical suspicion. Therapeutically, it is of limited alternatives. Currently, interferon-α is the most extensively studied agent in the treatment of ECD and serves as the first line of treatment. Treatment with other agents is based on anecdotal case reports and on the basis of biological rationale. Nevertheless, cladribine (2CDA), anakinra and vemurafenib are currently advocated as promising second line treatments for patients whose response to interferon-α is unsatisfactory. Overall, the 5 year survival of ECD is 68%. Herein, the authors mustered and brought about a panoramic consolidation of all the relevant facts regarding ECD. This work highlights the different clinical, radiological and pathological manifestations associated with ECD, the differential diagnoses, the various treatment options and the acknowledged science explaining the disease.