Erdheim-Chester Disease

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.

Cutaneous manifestations of Erdheim-Chester disease (ECD): Clinical, pathological, and molecular features in a monocentric series of 40 patients

BACKGROUND

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis with possible cutaneous-specific involvement.

OBJECTIVES

We sought to describe the clinical, pathological, and molecular features of the cutaneous manifestations of 40 patients with ECD identified from a cohort of 123 patients.

METHODS

Confirmed cases of patients with ECD were included in a single-center retrospective observational study. Clinical and pathological cutaneous features were analyzed and BRAF(V600E) mutation was determined.

RESULTS

The most frequent ECD cutaneous manifestations were xanthelasma-like lesions (XLL), which occurred in 31 (25%) patients. Other ECD cutaneous lesions were patches or papulonodular lesions. Mixed form of ECD and cutaneous Langerhans cell histiocytosis presented with crusty papules of the folds in some patients. Compared with classic xanthelasma palpebrarum, ECD XLL pathology more frequently involved the reticular dermis, displayed more multinucleated or Touton cells, and showed less extensive fibrosis. BRAF(V600E) mutation was more frequently detected in patients with cutaneous involvement than in those without (76% vs 52%; P = .005) and constantly found in 10 XLL.

LIMITATIONS

Some clinical data were not available because of the retrospective design of the study.

CONCLUSIONS

XLL are the most frequent cutaneous ECD manifestations and might be targeted both for pathology and determination of BRAF mutational status.

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.

Eosinophilia in Rheumatologic/Vascular Disorders

Peripheral and tissue eosinophilia can be a prominent feature of several unique rheumatologic and vascular diseases. These diseases span a wide range of clinical features, histologic findings, therapeutic approaches, and outcomes. Despite the rare nature of these entities--which makes large-scale studies challenging--knowledge has continued to grow regarding their epidemiology, pathophysiology, and management. This review compares and contrasts 5 rheumatologic and vascular conditions in which eosinophilia can be seen: eosinophilic granulomatosis with polyangiitis (Churg-Strauss), immunoglobulin G4-related disease, diffuse fasciitis with eosinophilia, eosinophilia-myalgia syndrome, and eosinophilic myositis.

Erdheim-Chester disease

Erdheim-Chester disease (ECD) is rare form of non-Langerhans cells histiocytosis with multiorgan involvement. Individuals are more frequently affected in their fifth decade and there is a slight male prevalence. Recent studies have demonstrated that ECD patients bare mutations in the proto-oncogene BRAF (and more rarely in other genes involved in the MAPK activation pathway), suggesting a critical role of this pathway in the pathogenesis and a possible clonal origin of the disease. Clinical manifestations are extremely protean and virtually every organ system can be affected. The most common clinical features include skeletal involvement with typical bilateral osteosclerotic lesions of long bones of the lower limbs, diabetes insipidus, cardiovascular involvement with circumferential thickening of the aorta ("coated aorta"), and retroperitoneal fibrosis ("hairy kidney"). Cardiovascular and central nervous system (CNS) involvement are associated with the worst prognosis. Biopsy is necessary to establish a definite diagnosis with the identification of CD68+/CD1a-/S100- foamy histiocytes. Currently, interferon-α is the first-line treatment in ECD, as it has been clearly demonstrated to increase overall survival. Anakinra and infliximab have also led to encouraging results and should be taken into consideration when treatment with interferon-α fails. More recently, the BRAF-inhibitor vemurafenib has been used in small groups of ECD patients with optimal efficacy in all treated cases. Nevertheless, its adverse effects and the scanty data on its long-term efficacy and safety still discourage its use as a first-line option. Further studies are still warranted to better understand and treat this neglected and overlooked 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.

Reproducible and sustained efficacy of targeted therapy with vemurafenib in patients with BRAF(V600E)-mutated Erdheim-Chester disease

PURPOSE

Histiocytoses are rare disorders with heterogeneous prognosis. BRAF(V600E) mutations have been observed in half of patients with Langerhans cell histiocytosis (LCH) and in 50% to 100% of patients with Erdheim-Chester disease (ECD) patients. We recently reported short-term efficacy of a BRAF inhibitor (vemurafenib) in three patients with multisystemic ECD.

PATIENTS AND METHODS

Vemurafenib was given to eight patients with multisystemic ECD with CNS and/or cardiac involvement. All patients were refractory to first-line treatment and harbored a BRAF(V600E) mutation. Four patients also had LCH lesions. Positron emission tomography (PET) scan response at month 6 was used as the main evaluation criterion. Secondary evaluation criteria were comparison at baseline and at last visit of PET and of cardiovascular and cerebral infiltrations (computed tomography scan and magnetic resonance imaging [MRI]).

RESULTS

All patients were partial metabolic responders at 6 months of vemurafenib, and the median reduction in maximum standardized uptake value was 63.5% (range, 41.3% to 86.9%). Evaluation of cardiac and aortic infiltrations showed that seven patients had a partial response and one patient had stable disease according to surface measurements derived from RECIST criteria. The four patients with infratentorial CNS infiltration had an objective decrease of the lesions on MRI. All patients had an improvement of general symptoms and a persistent response to vemurafenib, with a median follow-up time of 10.5 months (range, 6 to 16 months). Skin adverse effects were frequent and severe.

CONCLUSION

Vemurafenib has an objective and sustained efficacy in BRAF(V600E)-mutated ECD as second-line therapy. In contrast to melanoma, no resistance has emerged to date after 6 to 16 months.

Erdheim-Chester disease with rare radiological features in a 14-year old girl with pre-B Acute Lymphocytic Leukemia and Diabetes Mellitus

We report a case of a 14 year-old girl with Diabetes Mellitus who was in remission with pre-B cell Acute Lymphoblastic Leukemia and subsequently diagnosed with Erdheim-Chester disease. Erdheim-Chester disease is a non-Langerhans cell histiocytosis and is very rare in children. In addition, the radiological features of the lesions are atypical and have not been reported in children. There is no known association between the three conditions and this is the first reported case in the literature. A literature review of Erdheim-Chester disease will be performed.

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.

Oncogene-induced senescence as a new mechanism of disease: the paradigm of erdheim-chester disease

Erdheim–Chester disease (ECD) is a rare form of systemic histiocytosis characterized by the diffuse infiltration of tissues by lipid-laden macrophages. As the clinical course and prognosis are highly influenced by site of disease involvement, ECD course ranges from asymptomatic to life threatening, with a reported global 5-year mortality of 30–40%. Whether ECD is an inflammatory or clonal disease in its nature has long been debated. The disease is characterized by a network of pro-inflammatory cyto/chemokines responsible for the recruitment and activation of histiocytes into ECD lesions, similarly to what reported in Langerhans cell histiocytosis (LCH). Growing evidence supports a central role of the oncogenic BRAF^V600E mutation in histiocytosis pathogenesis, and suggests oncogene-induced senescence (OIS), a major protective mechanism against oncogenic events characterized by cell-cycle arrest and the induction of pro-inflammatory molecules, as the possible link between the oncogenic mutation and the observed inflammation. Indeed, ECD recapitulates in vivo the molecular events associated with OIS, i.e., cell-cycle arrest and a potent local inflammatory response. Accordingly, the infiltration of different tissues by macrophages and the inflammatory local and systemic effects observed in ECD likely represent a drawback of OIS. Therefore, these findings delineate a new conception of OIS as a new pathogenic mechanism intrinsically responsible for disease development.

Association of both Langerhans cell histiocytosis and Erdheim-Chester disease linked to the BRAFV600E mutation

Histiocytoses are a group of heterogeneous diseases that mostly comprise Langerhans cell histiocytosis (LCH) and non-LCH. The association of LCH with non-LCH is exceptional. We report 23 patients with biopsy-proven LCH associated with Erdheim-Chester disease (ECD) (mixed histiocytosis) and discuss the significance of this association. We compare the clinical phenotypes of these patients with those of 56 patients with isolated LCH and 53 patients with isolated ECD. The average age at diagnosis was 43 years. ECD followed (n = 12) or was diagnosed simultaneously with (n = 11) but never preceded LCH. Although heterogeneous, the phenotype of patients with mixed histiocytosis was closer to that of isolated ECD than to that of isolated LCH (principal component analysis). LCH and ECD improved in response to interferon alpha-2a treatment in only 50% of patients (8 of 16). We found the BRAF(V600E) mutation in 11 (69%) of 16 LCH lesions and in 9 (82%) of 11 ECD lesions. Eight patients had mutations in both ECD and LCH biopsies. Our findings indicate that the association of LCH and ECD is not fortuitous and suggest a link between these diseases involving the BRAF(V600E) mutation.

Visualization of orbital involvement of Erdheim-Chester disease on PET/CT

We report a 58-year-old man who presented with swelling and redness in his left eye, headache, and blurred vision. A contrast-enhanced CT of the orbits revealed bilateral orbital masses. Whole-body PET/CT showed bilateral retrobulbar hypermetabolic soft tissue lesions, multiple areas of soft tissue involvement, and osseous lesions in bilateral lower extremities. An open surgical biopsy of the left orbital mass revealed xanthomatous non-Langerhans histiocytic infiltrate with Touton giant cells, positive for CD68 but negative for CD1a, establishing a diagnosis of Erdheim-Chester disease.

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.

[An ophthalmologic diagnostic error leading to a rare systemic diagnosis: Erdheim-Chester disease]

INTRODUCTION

Erdheim-Chester disease is a rare systemic disease. The diagnosis is difficult due to significant clinical and morphological polymorphism. Orbital involvement is rare, but constitutes a classic means of detection.

OBSERVATION

We report the case of a 60-year-old man, who consulted for evaluation of bilateral retro-orbital tumors. These tumors had been discovered on head CT two years previously during work-up of proptosis. Two biopsies were performed. The first one revealed polymorphous inflammatory tissue. The second one revealed intense granulomatous reaction, rich in non-specific foamy histiocytes. Thoracic-abdominal-pelvic CT scan detected peri-aortic and retroperitoneal infiltration. The association of these signs pointed to a diagnosis of Erdheim-Chester disease, confirmed by the re-examination of the histological samples.

DISCUSSION

Erdheim-Chester disease is a rare non-Langerhans histiocytosis with a specific tropism for perivascular and fatty connective tissue. The cause is not known. The diagnosis of this systemic disease is histological.

CONCLUSION

In the case of bilateral intra-orbital tumors, the diagnosis of Erdheim-Chester disease must be considered.

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.