Erdheim–Chester disease

Coronary Artery Vasculitis and Encasement: Multimodality Imaging Findings and Mimics

Coronary artery vasculitis (CAV) and coronary artery encasement are rarely diagnosed conditions that are important diagnostic considerations, particularly in patients with acute coronary syndrome without traditional cardiovascular risk factors or systemic illness. Vasculitis refers to inflammation of the blood vessel walls, which can be primary or secondary. This process should be distinguished from neoplastic involvement of the coronary arteries, termed coronary artery encasement. Prospective diagnosis of these diseases is challenging, often requiring multidisciplinary workup with careful attention to clinical presentation and multiorgan findings. While CAV and coronary artery encasement can be indistinguishable at coronary CT angiography, certain imaging features help order the differential diagnosis. CAV should be considered when there is smooth wall thickening that is circumferential and/or continuous. A diagnosis of coronary artery encasement is favored when there is irregular or nodular wall thickening that is eccentric to the vessel lumen. Epicardial fat stranding may also appear more extensive compared with CAV. Potential mimics of CAV include atherosclerosis, acute plaque rupture, coronary artery aneurysm, and spontaneous coronary artery dissection. Detection and diagnosis of CAV may help avoid complications related to accelerated atherosclerosis and infarction. Radiologists should be familiar with the range of pathologic conditions that can affect the coronary arteries beyond atherosclerosis as they may be the first to raise such diagnostic possibilities, guiding next steps in patient workup and management. ©RSNA, 2024 Supplemental material is available for this article.

CD68-Negative Histiocytoses with Cardiac Involvement, Associated with COVID-19

Histiocytoses are rare diseases characterised by infiltration of affected organs by myeloid cells with a monocyte or dendritic cell phenotype. Symptoms can range from self-resolving localised forms to multisystemic lesions requiring specific treatment. To demonstrate extremely rare cases of CD68-negative cardiac histiocytosis with expression of SARS-CoV-2 antigen in infiltrate cells. We demonstrated a case of Erdheim-Chester disease in a 67-year-old man with pericardial involvement and positive dynamics with vemurafenib treatment, an autopsy case of xanthogranulomatous myopericarditis in a 63-year-old man, surgical material of xanthogranulomatous constrictive pericarditis in a 57-year-old man, and an autopsy case of xanthogranulomatosis in a 1-month-old girl. In all cases, xanthogranuloma cells expressed CD163, many of them spike protein SARS-CoV-2, while CD68 expression was detected only in single cells. In this article, we demonstrated four cases of extremely rare CD68-negative cardiac xanthogranulomatosis in three adults and one child with expression of the spike protein SARS-CoV-2 in M2 macrophages. This potential indirect association between COVID-19 and the development of histiocytosis in these patients warrants further investigation. To substantiate this hypothesis, more extensive research is needed.

Erdheim-Chester disease: An elusive diagnosis in a 50-year-old Ethiopian man presenting with diffuse sclerotic bone lesion

Key Clinical Message

Diagnosis of Erdheim-Chester disease (ECD) requires the clinician to be familiar with its various manifestations, classic radiologic and histologic features. This case highlights the significance of considering ECD in any patient presenting with bone pain and symmetric osteosclerosis of long bones of extremities to allow for early diagnosis and treatment.

Abstract

Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytic disorder with diverse clinical manifestations, ranging from indolent, localized presentation to life-threatening, multi-systemic disease. Delayed or erroneous diagnosis is common. The presence of classic radiographic finding along with foamy histiocytes that is positive for CD68 but negative for CD1a on histologic examination establishes the diagnosis. We report a second case of ECD from Ethiopia. A 50-year-old Ethiopian man presented with a 13-year history of bilateral lower leg bone pain, cold intolerance, somnolence, constipation, impotence, decreased libido, and secondary infertility. The diagnosis was suspected when skeletal X-ray revealed bilateral symmetric sclerosis of metadiaphysis of femur, tibia, and humerus. The demonstration of foamy histiocytes that were positive for CD68 but negative for CD1a on histologic examination with immunohistochemical staining confirmed the diagnosis. Evaluation for the extent of the disease revealed coated aorta sign, hairy kidney sign, and cystic lesion with ground glass opacity of lung, primary hypothyroidism, and hypergonadotropic hypogonadism. ECD is rare histiocytic neoplasm with wide range of clinical features which often delay the diagnosis. Clinician should be mindful of the various presentations and the classic radiographic and histologic features of ECD. This case highlights the significance of entertaining ECD in any patient presenting with lower leg bone pain and symmetric osteosclerosis of long bones of lower extremities to allow for early diagnosis and treatment.

Advances in Understanding and Management of Erdheim-Chester Disease

Erdheim Chester Disease (ECD) is a rare histiocytic disorder marked by infiltration of organs with CD68+ histiocytes. ECD stems from mutations of BRAF and MAP2K1 in hematopoietic stem and progenitor cells (HSPCs), which further differentiate into monocytes and histiocytes. Histopathology reveals lipid-containing histiocytes, which test positive for CD68 and CD133 in immunohistochemistry. Signs and symptoms vary and depend on the organ/s of manifestation. Definitive radiological results associated with ECD include hairy kidney, coated aorta, and cardiac pseudotumor. Treatment options primarily include anti-cytokine therapy and inhibitors of BRAF and MEK signaling.

Typical Bone Scintigraphy Presentation of Erdheim-Chester Disease in a Patient Diagnosed With IgG4-Related Disease

ABSTRACT

A 50-year-old woman presented a dry syndrome, joint pain, inflammatory syndrome, polyclonal hypergammaglobulinemia, and tubulointerstitial nephritis. Imaging studies (including FDG PET/CT) revealed infrarenal retroperitoneal fibrosis with periaortitis and hypermetabolic osteosclerotic lesions. Bone scintigraphy demonstrated intense uptake in the femoral, tibial, and radial regions, suggestive of non-Langerhans histiocytosis, specifically Erdheim-Chester disease. A bone biopsy confirmed the presence of IgG4-positive plasma cells but no histiocytes. The patient received corticosteroid therapy followed by rituximab, resulting in a complete response. This case suggests an atypical manifestation of bone lesions in IgG4-related disease, emphasizing the diagnostic challenge between IgG4-related disease and Erdheim-Chester disease.

Neuroimaging manifestations of paediatric histiocytoses

Histiocytoses are rare multi-system disorders marked by abnormal histiocyte cell proliferation, affecting children with diverse clinical presentations. Classified into five groups in 2016, including Langerhans-related (L), cutaneous (C), malignant (M), Rosai-Dorfman disease (R) and haemophagocytic lymphohistiocytosis (H), newer entities such as ALK-positive histiocytosis have also emerged, heralding the era of molecular (sub)classification. Common entities include Langerhans cell histiocytosis (LCH), Erdheim-Chester disease (ECD), Rosai-Dorfman disease (RDD) and haemophagocytic lymphohistiocytosis (HLH). This pictorial essay aids radiologists in recognising and differentiating paediatric histiocytoses based on unique neuroimaging features.

Vasculitis Mimics and Other Related Conditions

The approach to diagnosis of primary systemic vasculitis can be challenging, often requiring consideration of important secondary causes of vasculitis and non-inflammatory mimics. An atypical pattern of vascular involvement and/or atypical features of primary vasculitis (eg, cytopenia, lymphadenopathy) should prompt a more thorough investigation into other diseases. Herein, we review selected mimics organized by the size of blood vessels typically affected.

Rare Cutaneous Manifestations of Erdheim Chester Disease: A Case Report and Literature Review

Erdheim Chester disease (ECD) is a rare and complex non-Langerhans histiocytic systemic disease that affects multiple organ systems, including the bones, heart, lungs, and central nervous system. Fewer than 1,000 cases have been reported in the medical literature and dermatological manifestations of the disease are rare but can provide valuable diagnostic clues for this challenging disease. The cutaneous manifestations of ECD can take many forms, including nodules, plaques, papules, and xanthomas. These lesions can occur on any part of the body and may be solitary or multiple. Cutaneous manifestations of ECD have been reported to occur in up to 20% of cases, but the true prevalence may be higher, as many cases may go undiagnosed. We present the case of a 62-year-old gentleman with a history of ECD currently on vemurafenib who presented with multiple painless subcutaneous nodules on his back after an excision biopsy under local anesthetic revealed histological features of ECD. The objective of this case report is to raise awareness of ECD and its dermatological manifestations. Further research is warranted to better understand the pathogenesis and morphology of cutaneous involvement in ECD.

Erdheim-Chester Disease of the Breast: First Review and First Case of Isolated Severe Gynecomastia

(1) Introduction: Erdheim-Chester disease (ECD) is a life-threatening condition and often a diagnostic challenge. It has recently been classified as a hematopoietic tumour, and the cases of ECD reported in the literature has dramatically increased during the last 15 years. (2) Methods: We describe the case of a 57-year-old male patient with severe gynecomastia, with a detailed description of his diagnostic iter and consequent surgical operation. We provide the first systematic review of the literature of breast involvement in ECD, following PRISMA guidelines, including 13 studies and 16 patients. (3) Results: Our report resulted to be the first case of gynecomastia as a single clinical and imaging feature of ECD described in English literature. A total of 81.3% of patients included were female. Among them, 76.9% had unilateral and nodular presentation, while male patients presented bilateral heterogeneous breast enlargement. Globally, 87.5% expressed breast alterations as their first manifestations of ECD. Only 50% presented skeletal involvement. (4) Conclusion: The reported case represents a unique addition to the literature. We found two different patterns in ECD-related breast involvement between male and female patients, an unusual M/F ratio, and a lower rate of bone involvement. Breast involvement is frequently the first clinical feature; therefore, breast caregivers should be aware of this dangerous and most likely underestimated condition.

Paediatric Erdheim-Chester Disease in the Lateral Ventricle: A Case Report and Review of the Literature

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis caused by the expression of CD68-positive and CD1a-negative foam tissue cells, which is polar in pediatric patients. The study reports a case of an 8-year-old Chinese boy who presented with polydipsia and polyuria for 4 years, followed by central nervous system symptoms. Magnetic resonance imaging (MRI) showed a large lesion in the lateral ventricle. The histiocytes stained positively for CD68, CD163 and negatively for CD1a, glial fibrillary acidic protein (GFAP) and langerin, and were partially positive for S100 by immunohistochemical assay. More importantly, BRAFV^600E staining was positive in tissue, and the BRAF^V600E mutations was also detected by real-time quantitative PCR (RT-qPCR) in the intracranial lesion tissue. According to our review of the literature, this is a rare case of ECD in the ventricle, with a younger age.

Endoscopic Transsphenoidal Resection of Suprasellar Histiocytosis in a Patient with Erdheim-Chester Disease: A Case Report

Erdheim–Chester disease (ECD) is a rare systemic disease characterized by non-Langerhans histiocytosis. Pituitary involvement, often manifesting as diabetes insipidus, is the most common central nervous system (CNS) lesion. However, significant mass formation compressing the optic apparatus is rarely reported. We present a case of ECD-related suprasellar mass treated with an endoscopic transnasal approach, with emphasis on the surgical strategy and the intraoperative findings. The mass was fibrous, significantly hard, and strongly adhered to the optic nerves, causing visual impairment. A subtotal resection was performed with preserving the adhesion between the mass and the optic nerves, and her visual symptoms improved remarkably after surgery. We highlight the surgical procedure of ECD-related suprasellar mass, from an endoscopic point of view. Due to strong adhesion of the mass to the surrounding optic apparatus and perforators, complete resection may be harmful; judicious mass reduction with preserving such adhesion would contribute to better visual outcomes.

Solitary Radiolucent Erdheim-chester Disease: A Case Report and Literature Review

Background:

Erdheim-chester disease (ECD) is a rare non-Langerhans histiocytosis of unknown etiology, which typically presents with bilateral symmetric osteosclerosis and multi-organ involvement. Lesions may be intraosseous or extraosseous and involve the heart, pulmonary system, CNS, and skin in order of decreasing likelihood.

Objective:

The objective of this study is to discuss a case of erdheim-chester disease and conduct a review of the literature.

Case:

We describe a rare case of erdheim-chester in an asymptomatic 37-year-old male who was diagnosed after suffering a right ulnar injury. Subsequent evaluation revealed a solitary radiolucent ulnar lesion without multi-system involvement.

Results & Conclusion:

The case is unique in its solitary distribution, lytic radiographic appearance, and asymptomatic presentation preceding pathologic fracture. This presentation may simulate multiple other bone lesions.

Histiocytic Neoplasms, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

Histiocytic neoplasms are rare hematologic disorders accounting for less than 1% of cancers of the soft tissue and lymph nodes. Clinical presentation and prognosis of these disorders can be highly variable, leading to challenges for diagnosis and optimal management of these patients. Treatment often consists of systemic therapy, and recent studies support use of targeted therapies for patients with these disorders. Observation ("watch and wait") may be sufficient for select patients with mild disease. These NCCN Guidelines for Histiocytic Neoplasms include recommendations for diagnosis and treatment of adults with the most common histiocytic disorders: Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease.

Three cases of BRAF mutation negative Erdheim-Chester disease with a challenging distinction from IgG4-related disease

Background

Erdheim-Chester disease (ECD) is a rare non-Langerhans histiocytosis with slow progression over the years that is particularly difficult to diagnose.

Cases

Here we report three cases of ECD without BRAF mutation presenting with a renal mass, hairy kidney appearance, and a rather benign course, for which the diagnosis of ECD was delayed, characterized by multiple investigations and unsuccessful treatments attempts. In two cases the distinction from IgG4-related disease required multiple investigations and reevaluation of the clinical, radiological, histological, and immunological characteristics.

Conclusion

A correct diagnosis of ECD may take several years and often requires revisiting previous hypotheses. Reassessment of histological slides and more modern complementary exams such as PET-CT or BRAF and MAPK-ERK mutation analysis can help to confirm the diagnosis of ECD and to select effective therapy.

Neuroendocrine manifestations of Erdheim-Chester disease

Neuroendocrine manifestations are common in Erdheim-Chester disease (ECD) patients. ECD is a rare non-Langerhans form of histiocytosis with multisystemic infiltration. The involvement of the hypothalamo-pituitary axis is common and central diabetes insipidus (CDI) is one of the most common endocrine manifestations in ECD patients. CDI is the first manifestation of ECD in 25%-48% of the cases. Suprasellar region extension, due to the infiltration of ECD lesions, can cause neurologic manifestations by mass effects, such as headache, visual disturbance, and cranial nerve palsies. Recent studies have revealed that disorders affecting anterior pituitary hormones are common in ECD patients. Secondary adrenal insufficiency, secondary hypothyroidism, (adult) growth hormone deficiency, hypogonadotropic hypogonadism, hyperprolactinemia, and hypoprolactinemia can develop as the neuroendocrine manifestations of ECD. Since the symptoms of anterior pituitary hormone deficiencies tend to be nonspecific, the diagnosis of anterior pituitary hormone dysfunctions can be delayed. Some anterior pituitary dysfunctions such as adrenocorticotropic hormone and/or thyroid-stimulating hormone deficiencies can be life-threatening without adequate hormone supplementation therapies. An endocrinological evaluation of the function of the pituitary gland should be performed at the initial diagnosis of ECD. It is important to recognize that endocrine dysfunctions can develop later during the follow-up of ECD.

Beyond Giant Cell Arteritis and Takayasu's Arteritis: Secondary Large Vessel Vasculitis and Vasculitis Mimickers

PURPOSE OF REVIEW

To provide an overview of mimickers of large vessel vasculitis (LVV), by the main presenting manifestation, i.e., systemic, vascular, and cranial manifestations.

RECENT FINDINGS

The main differential diagnoses in patients with giant cell arteritis (GCA) and Takayasu arteritis (TAK) presenting with systemic manifestations (i.e., fever, anorexia, weight loss, night sweats, arthralgia/myalgia, and/or increased inflammatory indexes) are neoplastic, infectious, or other inflammatory conditions. In patients with vascular manifestations (such as peripheral ischemia, vascular stenoses, or aneurysms), atherosclerosis and non-inflammatory vascular diseases should be excluded. In those presenting with predominant cranial symptoms (i.e., temporal headache, jaw claudication, scalp tenderness, transient or permanent vision loss), other causes of headache, cerebrovascular accidents, optic neuropathy, and neuromuscular syndromes need to be considered. The diagnosis of LVV maybe challenging, especially when patients present with atypical or incomplete clinical forms. In these cases, a multidisciplinary approach is strongly recommended.

MRI features of intra-axial histiocytic brain mass lesions

AIM

To describe MRI features, including diffusion-weighted imaging (DWI), magnetic resonance spectroscopy (MRS), and perfusion-weighted imaging (PWI), of intra-axial tumour-like presentations of four different subtypes of histiocytosis.

MATERIAL AND METHODS

The brain MRI findings of 23 patients with histologically proven histiocytosis were reviewed retrospectively (11 Langerhans cell histiocytosis [LCH], eight Erdheim-Chester disease [ECD], one overlap form LCH/ECD, two Rosai-Dorfman disease [RDD], and one haemophagocytic lymphohistiocytosis [HLH]) with single or multiple enhancing intraparenchymal brain lesions.

RESULTS

Histiocytic brain mass lesions show some similar MRI features including Supra and/or infratentorial and/or paraventricular subcortical well-delineated masses, linear ependymal enhancement along the ventricles and brain stem lesions. Masses always present with mixed hyper- and hypointense signal on T2-weighted imaging (WI). Their enhancement is often homogeneous. Apparent diffusion coefficient (ADC) values are often normal or elevated.

CONCLUSION

The presence of multiple periventricular and subcortical enhancing lesions with mixed signal intensity on T2WI and normal or high ADC values should lead radiologists to consider the diagnosis of histiocytic lesions and search for associated systemic lesions.

[Erdheim-Chester disease presenting with bilateral orbital involvement: Report of three cases]

PURPOSE

To report treatment outcomes of orbital tumors associated with Erdheim-Chester disease and to highlight the importance of systemic work-up in patients presenting with bilateral proptosis.

PATIENTS AND METHODS

Three patients with Erdheim-Chester disease, whose initial manifestation was bilateral proptosis, were retrospectively studied. The course of onset, clinical, imaging and histopathological features, systemic associations and response to treatment were reviewed. The main outcome measures were Hertel measurements and orbital tumor regression on imaging studies.

RESULTS

All patients presented with bilateral non-pulsatile proptosis resistant to retropulsion and headeache without specific localization. Magnetic resonance imaging studies showed bilateral intraconal orbital tumors. Incisional biopsy of these tumors demonstrated CD68+, CD1a-, and S100- histiocytic infiltrates consistent with the diagnosis of Erdheim-Chester disease. The BRAFV600E mutation was found in all cases. Systemic work-up revealed asymptomatic bony involvement in the lower extremities, perirenal fibrosis, central nervous system and cardiac involvement. All patients initially received pegylated interferon-α2a, which resulted in excellent responses except for the orbital tumors. Two patients were then treated with vemurafenib, which resulted in rapid regression of the orbital lesions.

CONCLUSION

Pegylated interferon-α was highly effective in the control of cardiac, perirenal, skeletal and cerebral involvement but not the orbital tumors. The infiltrative orbital lesions of Erdheim-Chester disease would appear more responsive to vemurafenib.

Retroperitoneal Erdheim-Chester disease without skeletal bone involvement mimicking uterine sarcoma with multiple organ involvement

Erdheim-Chester disease (ECD) is a rare type of non-Langerhans cell histiocytosis and is characterized by the diffuse histiocytic infiltration of multiple organs. Retroperitoneal ECD, especially with uterine involvement, is extremely rare. We report about a 73-year-old woman who presented with vaginal spotting for a month and experienced abdominal pain along with pus-like urine. Computed tomography revealed an irregular mass-like lesion in the uterus, possibly a uterine sarcoma, invading the ureter, rectosigmoid, and bladder. A tissue biopsy of the retroperitoneal mass revealed typical morphological and immunohistochemical features of ECD. However, clinical features, especially long bone involvement, did not coincide with ECD, and BRAF V600E gene mutation was not detected. We made a diagnosis of atypical retroperitoneal ECD mimicking uterine sarcoma with multiple organ involvement.

Erdheim-Chester Disease: A Case Report and Review of the Literature

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans’ cell histiocytosis characterized by xanthogranulomatous infiltration of foamy histiocytes surrounded by fibrosis. ECD may be asymptomatic or present as a multi-systemic disease with life-threatening manifestations, most commonly involving the skeletal system. Immunohistochemical staining demonstrates cells that are CD68+, CD1a–, and S100– with an absence of Birbeck granules. We report a case of a 69-year old male patient who presented with neurological symptoms – eventually thought to be separate to his diagnosis of ECD. It represents the ability to diagnose ECD based just on radiological findings in an otherwise asymptomatic individual.

Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare but increasingly recognized multi-system disorder. Its diagnosis and treatment require integration of clinical information, imaging studies, and pathology studies. Of note, ECD can now be defined as a clonal myeloid disorder due to mutations which activate mitogen-activated protein kinase (MAPK) pathways and where an inflammatory milieu is important in the pathogenesis and clinical manifestations of the disease. Biopsy demonstrating characteristic histopathologic features in addition to clinical and radiographic features, most often sclerosing long bone involvement, is required to establish a diagnosis. Detection of somatic MAPK pathway mutations can also assist in the differential diagnosis of ECD and related histiocytic neoplasms. Also, genetic analysis establishing BRAF and RAS mutational status is critical in all ECD patients, as these features will impact therapy with MAPK inhibition. Therapy is recommended at diagnosis in all patients, except for those patients with minimally symptomatic disease. Prospective therapeutic trials are essential to furthering therapeutic progress in ECD.

Erdheim-Chester disease: a case treated with IFN-α monitored using plasma and urine cell-free DNA

Erdheim-Chester disease is a rare form of non-Langerhans histiocytosis. A 40-year-old woman was diagnosed as Erdheim-Chester disease based on typical bone scintigraphy, symmetric osteosclerosis and findings of foamy, non-Langerhans histiocytes in bone marrow. BRAF^V600E mutation was detected in a bone biopsy. Treatment with IFN-α showed significant improvement. The BRAF^V600E mutant was detected in plasma cell-free DNA (cfDNA) by a droplet-digital PCR assay. Longitudinal analysis of BRAF^V600E in plasma cfDNA showed a decreasing trend during treatment. We could not detect the mutant in urinary cfDNA. While, similar studies have detected the BRAF^V600E mutant in urine, but not in plasma. A combination of allele burden assessments in plasma and urine may be helpful for detecting the residual mutant burden and monitoring therapeutic response.

The Mayo Clinic Histiocytosis Working Group Consensus Statement for the Diagnosis and Evaluation of Adult Patients With Histiocytic Neoplasms: Erdheim-Chester Disease, Langerhans Cell Histiocytosis, and Rosai-Dorfman Disease

Histiocytic neoplasms, a rare and heterogeneous group of disorders, primarily include Erdheim-Chester disease, Langerhans cell histiocytosis, and Rosai-Dorfman disease. Due to their diverse clinical manifestations, the greatest challenge posed by these neoplasms is the establishment of a diagnosis, which often leads to a delay in institution of appropriate therapy. Recent insights into their genomic architecture demonstrating mitogen-activated protein kinase/extracellular signal-regulated kinase pathway mutations have now enabled potential treatment with targeted therapies in most patients. This consensus statement represents a joint document from a multidisciplinary group of physicians at Mayo Clinic who specialize in the management of adult histiocytic neoplasms. It consists of evidence- and consensus-based recommendations on when to suspect these neoplasms and what tests to order for the diagnosis and initial evaluation. In addition, it also describes the histopathologic and individual organ manifestations of these neoplasms to help the clinicians in identifying their key features. With uniform guidelines that aid in identifying these neoplasms, we hope to improve the awareness that may lead to their timely and correct diagnosis.

Histiocytic and Dendritic Cell Neoplasms

Histiocytic and dendritic cell neoplasms are very rare, belonging to a group that share morphologic, immunophenotypic, and ultrastructural characteristics of mature histiocytic/dendritic neoplasms. Histiocytic and dendritic cell neoplasms may arise de novo or in association with B-cell, T-cell, or myeloid neoplasms. Recent molecular findings, particularly the discoveries of the mutations in the RAS-RAF-MEK-ERK pathway, have greatly advanced the diagnosis and treatment options. Histiocytic and dendritic cell neoplasms may closely resemble each other, non-hematopoietic neoplasms, and even reactive processes. Therefore, it is essential to understand the clinicopathologic characteristics, differential diagnoses, and pitfalls of each entity.

The Challenges of Pediatric Drug Development

INTRODUCTION AND BACKGROUND

"Pediatric Drug Development" is being used to describe not the development of drugs for children, but rather the planning & conducting separate efficacy and safety (E&S) studies requested/demanded by regulatory authorities designed to produce pediatric labels. Pediatric studies required for drug approval enroll "children"; defined as <17 years of age (US Food and Drug Administration [FDA])/ <18 years (European Union [EU]). The medical rationale for study designs was examined.

MATERIAL & METHODS

International industry-sponsored pediatric E&S studies registered in www.clinicaltrials.gov were analysed along with the history of US/EU laws, published literature, internet-retrieved regulatory documents, and regulatory/ American Academy of Pediatrics (AAP) justifications for doing separate pediatric E&S studies.

RESULTS

US/EU regulators utilize an official, but non-physiological definition of childhood based on an age limit of 17/18 years. This definition, which blurs the interface between medicine and law, emerged after clinical studies became required for drug approval in 1962 prompting drug manufacturers to insert pediatric warnings into product information. Intended largely as legal protection against liability, they were interpreted medically. Absorption, distribution, metabolism, excretion mature rapidly. Drug toxicities seen in newborns during the first months of life were cited by AAP/FDA in warnings of dangers of drugs in all "children" including in adolescents who are physiologically no longer children. Warnings were/are exaggerated, exploit/ed parents' protective instincts and fears, and increase/d pediatric clinical trial activity. Conflicts of interest created by this increased activity involve research funding, career status & advancement, commercial profits.

DISCUSSION

FDA/EMA-requested/demanded "pediatric" studies were identified which lack medical sense at best, others actually harm young patients by impeding use of superior, effective treatments. Separate labels for different indications make medical sense; separate approval in persons above/below 17/18 years of age does not.

CONCLUSIONS

Pediatric medical research should be restricted to studies which meet important medical needs of all recruited young patients, which generate information that cannot be obtained by other study designs, and do not limit access to superior alternative therapies. Clinical centers, investigators, and IRBs/ECs should more carefully examine studies for unjustified regulatory demands, prevention of subjects' access to superior treatments, and undeclared COI's. Questionable studies should not be approved and ongoing ones should be suspended.

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.

Cladribine treatment for Erdheim-Chester disease involving the central nervous system and concomitant polycythemia vera: A case report

Erdheim–Chester disease (ECD), a rare form of non-Langerhans cell histiocytosis, is characterized by the infiltration of foamy CD68⁺ and CD1a^- histiocytes into multiple organ systems. Central nervous system (CNS) involvement has recently been reported to be a poor prognostic factor when treating ECD with interferon alpha. We report the case of a 66-year-old Japanese patient with ECD involving the CNS who harbored the BRAF V600E mutation and also concomitantly developed polycythemia vera with the JAK2 V617F mutation. We confirmed 2-chlorodeoxyadenosine (cladribine) therapy to be effective for the patient in this case.

Computed tomography and magnetic resonance imaging of peripelvic and periureteric pathologies

Peripelvic and periureteric areas are frequently overlooked in the imaging evaluations of the urinary system on computed tomography and magnetic resonance imaging. Several neoplastic and non-neoplastic disorders and diseases including lipomatosis, angiomyolipoma and angiolipomatous proliferation, vascular lesions, lymphangiomatosis, Rosai-Dorfman disease, Erdheim-Chester disease, extramedullary hematopoiesis, IgG4-related disease, lymphoma, mesenchymal tumors, trauma, and Antopol-Goldman lesion may involve these areas. Differentiation of these benign or malignant pathologies among themselves and from primary renal pathologies is of utmost importance to expedite the triage of patients for correct treatment approach. In this article, we aim to increase the awareness of the imaging specialists to the typical and atypical imaging features of the entities affecting these areas.

[Preliminary study on surgical treatment of Erdheim-Chester disease]

Objective

To summarize the preliminary effectiveness of surgical treatment of Erdheim-Chester disease (ECD), so as to improve the understanding of the disease by orthopedic surgeons.

Methods

The clinical data of 9 patients with ECD between December 2012 and October 2017 were retrospectively analysed. There were 6 males and 3 females with an median age of 42 years (range, 8-61 years). The disease duration was 4-59 months (mean, 39 months). There were 2 cases of multiple lesions, including 1 case involving soft tissue of the buttocks and bilateral tibia, 1 case involving the sinus, skull base, and proximal right tibia; 7 cases with single lesion, including 3 cases of right femoral neck, 1 case of proximal right tibia, 1 case of right humerus, and 2 cases of ribs. Nine patients were diagnosed according to clinical manifestations, imaging examination, and pathological diagnosis. Four patients underwent needle biopsy before operation and 5 patients were diagnosed by postoperative pathology examination. Five cases underwent lesional scraping and internal fixation, 1 case underwent bone scraping and bone grafting, and 3 cases underwent lesion resection. One of the multiple lesions was treated with interferon and hormone.

Results

Nine patients underwent the surgery safely. There was no fever, wound exudation, infection, etc., and the incisions healed by first intention. All the patients were followed up 4-59 months with an average of 31.4 months. One patient with bilateral tibia and hip soft tissue involvement continued to receive medical treatment, and the tumor was controlled without significant increasing. The remaining 8 patients were examined for X-ray films at 3, 6, and 12 months after surgery, the bone has been fused and the steel plate and intramedullary nail were firmly fixed, and no tumor recurrence was observed. At 1 year after surgery, the pain symptoms of the patients improved and returned to normal life; 3 of them who involving the right femoral neck walked freely, and the quality of life improved significantly.

Conclusion

ECD patients can achieve the purpose of eliminating lesions and relieving pain after surgical treatment, and the surgical treatment has the advantages of quick relief of pain, improved quality of life, small side effects, and low economic cost when compared with medical treatment.

Rare diseases of bone: Erdheim-Chester and Rosai-Dorfman non-Langerhans cell histiocytoses

Non-Langerhans cell histiocytosis (N-LCH) summarizes a group of rare diseases with different clinical presentations, pathogenesis and morphology. These include primary cutaneous N-LCH, cutaneous N-LCH with systemic involvement, and primary extracutaneous systemic forms with occasional cutaneous involvement.

The juvenile (JXG) and non-juvenile xanthogranuloma (N-JXG) family of histiocytoses are N-LCH: the JXG family consisting of the JXG (cutaneous), xanthoma disseminatum (cutaneous and systemic) and Erdheim-Chester disease (ECD; systemic); and the N-JXG family consisting of the solitary reticulohistiocytoma (cutaneous), multicentric reticulohistiocytosis (cutaneous and systemic) and Rosai-Dorfman disease (RDD; systemic).

ECD is a clonal disorder from the JXG family of N-LCH; RDD is a reactive proliferative entity from the non-juvenile xanthogranuloma family of N-LCH.

ECD and RDD N-LCH are rare disorders, which are difficult to diagnose, with multi-organ involvement including bone and systemic symptoms, and which respond to therapy in an unpredictable way.

The key to successful therapy is accurate identification at tissue level and appropriate staging. Patients should be observed and monitored in a long-term pattern. Prognosis depends on disease extent and the organs involved; it is generally good for RDD disease and variable for ECD.

Cite this article: EFORT Open Rev 2018;3:381-390. DOI: 10.1302/2058-5241.3.170047

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

OBJECTIVES

To investigate the computed tomography (CT) thoracic findings in Erdheim-Chester disease (ECD) and evaluate the association of these findings with the BRAF^V600E mutation.

METHODS

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 BRAF^V600E was achieved via the Chi-square or Fisher's exact test and odds ratios (OR) with 95% confidence intervals (CI), as appropriate.

RESULTS

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 BRAF^V600E mutation, positive in 31 patients, was associated with the frequency of sheathing of the coronary arteries (p = 0.01).

CONCLUSIONS

Of the thoracic findings reported in this study, we found a statistically significant positive association between the BRAF^V600E mutation and presence of coronary artery sheathing.

KEY POINTS

• 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.

Superior efficacy and similar safety of double dose anakinra in Erdheim-Chester disease after single dose treatment

Objectives. In Erdheim-Chester disease (ECD), the empirical single dose (SD, 100 mg/day) anakinra sometimes induces only partial responses. Since SD is usually well tolerated, doubling the dose might improve response while maintaining an acceptable safety profile. Methods. A retrospective analysis was performed of outcomes under double-dose (DD) of anakinra in 4 ECD patients who did not exhibit a complete response (CR) under SD treatment. Bone, retroperitoneal, neurologic/orbital, peritoneal, pericardial, right atrium, and pleural involvements were recorded. CR, partial response (PR), stable disease, progressive disease (PD) and tolerance of DD were assessed. Results. SD treatment was a second or third line treatment in three patients after interferon-therapy failure. Two patients, including one with a BRAF mutation, achieved a CR and one patient with a NRAS mutation achieved a PR with DD treatment. The fourth patient, wild-type for both genes, did not respond to a first DD treatment, but then achieved CR under SD associated with a reduced dose of vemurafenib (960 mg/d). Bone and retroperitoneal lesions partially improved on imaging with SD in all patients, but were further improved under DD with two patients achieving CR. With SD treatment, two patients with right atrial masses showed sustained CR. Under DD treatment, two patients with massive serositis refractory to SD, showed PR. Conclusion. DD improved the response to anakinra and lead to two CRs and a PR in three out of four ECD patients, with minor and comparable side-effects to those of SD, while failures were essentially related to massive serositis.

CNS Erdheim-Chester Disease: A Challenge to Diagnose

Erdheim-Chester disease (ECD) is a rare nonLangerhans cell histiocytosis. Although approximately 50% of cases eventually involve the central nervous system (CNS), the CNS has seldom been reported as the initial biopsy site. The diagnosis of CNS ECD can be challenging due to morphologic overlap with reactive histiocytic proliferation, Langerhans cell histiocytosis (LCH), and extranodal Rosai-Dorfman disease (RDD). We present 3 cases from our files that illustrate the protean manifestations of ECD. Case 1 was a 47-year-old man with ataxia, dysarthria, and intermittent ophthalmoplegia whose cerebellar biopsy had shown only profuse, nonspecific Rosenthal fiber-rich piloid gliosis; ECD was diagnosed only at autopsy. The gliosis and marked variations in histiocyte morphology in different anatomical sites added to the diagnostic challenge. Case 2 was a 67-year-old female with chronic progressive symptoms and a pontine lesion that had been considered to be CLIPPERS by neuroimaging. Identification of a BRAFV600E mutation allowed an ECD diagnosis and treatment with the specific BRAFV600E inhibitor vemurafenib, which resulted in a marked sustained clinical response. Case 3 was diagnosed as ECD after positive bone biopsy with typical foamy histiocytes. Six years later, there was massive dural involvement that showed RDD-like, BRAF-mutation-negative histiocytosis. These cases highlight the clinical and histologic overlap that can occur among these disorders.

A rare case of CD1a-negative Langerhans cell histiocytosis of the central nervous system in a child

Langerhans cell histiocytosis is a dendritic cell disorder with a wide spectrum of severity and presentations. Histopathology typically demonstrates a proliferation of Langerhans cells and a lymphohistiocytic inflammatory infiltrate with eosinophils. The diagnosis is supported by immunohistochemistry with the cell markers S100, CD1a, CD68, and Langerin [Blood, 126, 2015, 26 and N Engl J Med, 331, 1994, 154].

Erdheim-Chester Disease Involving the Central Nervous System with the Unique Appearance of a Coated Vertebral Artery

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis. It is characterized by multiple xanthogranulomatous masses throughout the body, predominantly in the tibia. One of the characteristic radiological findings of the lesions associated with ECD is a “coated artery,” which is often observed in the aorta. Although approximately one-fourth of ECD cases involve the central nervous system (CNS), an intracranial-coated artery has only been reported in four cases. We report a case of ECD that involves the CNS and has the unique appearance of a coated vertebral artery (VA). These tumors entirely encase the bilateral VAs without stenosis and are attached to the dura. Cranial magnetic resonance imaging also showed multiple extra-axial tumors in the cavernous sinus, the frontal convexity, and the orbital cavity. Further investigation revealed additional extracranial lesions around the cervical carotid artery, at the bilateral tibia, and at the elbow joint. A biopsy of the cervical and tibial lesions confirmed ECD. Steroid therapy resulted in a month-long improvement of preoperative symptoms. However, the patient’s condition gradually progressed and he died of pneumonia 1 year after ECD diagnosis. The encasement of the intracranial artery by the tumor without stenosis and the dural attachment suggest ECD, which requires whole body investigation.

Inflammatory serum cytokines and chemokines increase associated with the disease extent in pediatric Langerhans cell histiocytosis

OBJECTIVE

Langerhans cell histiocytosis (LCH) is characterized by immature dendritic cell proliferation, infiltration of LCH lesions by various inflammatory cells, and a lesional cytokine storm. It is classified into three groups on the basis of disease extent, namely, multisystem with risk-organ involvement (MS+), multisystem without risk-organ involvement (MS-), and single-system (SS) disease. We comprehensively analyzed whether serum levels of cytokines/chemokines reflect the disease extent.

METHODS

Serum samples from 52 children with LCH (eight, 25, and 19 with MS+, MS-, and SS, respectively) and 34 control children were analyzed quantitatively for 48 humoral factors. DNA samples extracted from biopsied LCH lesions from 12 patients were tested for BRAF V600E status.

RESULTS

The LCH patients had significantly higher serum levels of IL-1Ra, IL-3, IL-6, IL-8, IL-9, IL-10, IL12, IL-13, IL-15, IL-17, IL-18, TNF-α, G-CSF, M-CSF, MIF, HGF, VEGF, CCL2, CCL3, CCL7, CXCL1, and CXCL9 than the controls by univariate analysis. Of these IL-9, IL-15 and MIF were significant by multivariate analysis; but not differed between MS and SS diseases. MS disease associated with significantly higher IL-2R, IL-3, IL-8, IL-18, M-CSF, HGF, CCL2, CXCL1, and CXCL9 levels than SS disease by univariate analysis. Of these, CCL2 and M-CSF were significant by multivariate analysis. IL-18 levels were significantly higher in MS+ disease than MS- disease. The LCH patients with BRAF V600E mutation had higher serum levels of CCL7.

CONCLUSION

Numerous inflammatory cytokines and chemokines play a role in LCH. Of those, more specific ones reflect the disease extent (MS vs. SS and MS+ vs. MS-) or the BRAF V600E mutation status. It is thought that the most responsible cytokines and chemokines involved in the poor outcome may become future candidate therapeutic targets in LCH.

Benign Bone Conditions That May Be FDG-avid and Mimic Malignancy

Positron emission tomography with the radiotracer ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) plays an important role in the evaluation of bone pathology. However, FDG is not a cancer-specific agent, and knowledge of the differential diagnosis of benign FDG-avid bone alterations that may resemble malignancy is important for correct patient management, including the avoidance of unnecessary additional invasive tests such as bone biopsy. This review summarizes and illustrates the spectrum of benign bone conditions that may be FDG-avid and mimic malignancy, including osteomyelitis, bone lesions due to benign systemic diseases (Brown tumor, Erdheim-Chester disease, Gaucher disease, gout and other types of arthritis, Langerhans cell histiocytosis, and sarcoidosis), benign primary bone lesions (bone cysts, chondroblastoma, chondromyxoid fibroma, desmoplastic fibroma, enchondroma, giant cell tumor and granuloma, hemangioma, nonossifying fibroma, and osteoid osteoma and osteoblastoma), and a group of miscellaneous benign bone conditions (post bone marrow biopsy or harvest status, bone marrow hyperplasia, fibrous dysplasia, fractures, osteonecrosis, Paget disease of bone, particle disease, and Schmorl nodes). Several ancillary clinical and imaging findings may be helpful in discriminating benign from malignant FDG-avid bone lesions. However, this distinction is sometimes difficult or even impossible, and tissue acquisition will be required to establish the final diagnosis.

Isolated pulmonary involvement in Erdheim-Chester disease

Erdheim–Chester disease is a rare non-Langerhans cell histiocytic disorder. It is primarily a disease of the long bones. Pulmonary involvement in systemic disease is detected in about half the reported cases. Isolated lung involvement is extremely rare with no clear recommendations for treatment. A 52-year-old caucasian male was evaluated for 1.9 cm × 1.6 cm spiculated nodule in the right upper lobe. Pulmonary function testing and bronchoscopy with endobronchial ultrasound, transbronchial biopsy, and microbiology were inconclusive. Positron emission tomography–computed tomography (PET-CT) was significant for the avidity in same lung nodule along with mediastinal and hilar adenopathy but no bone involvement. Wedge resection with histopathology and immunohistochemistry reported a fibrohistiocytic infiltrate in bronchovascular distribution which was positive for CD68 and negative for CD1A, S100, and BRAF V600E mutation. Magnetic resonance imaging brain ruled out central nervous system involvement. The rarity of the condition along with the complex pathology makes it difficult to diagnose and hence intervene appropriately.

Erdheim-Chester disease with bilateral Achilles tendon involvement

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis with a broad spectrum of organ manifestations, presenting with characteristic radiological and histological findings. Soft tissue manifestations (xanthogranulomas) have been reported to be most commonly found in the region of the orbits. We report bilateral Achilles tendon xanthogramlomas in a 36-year-old male with biopsy-proven and B-RAF V600E-positive ECD. Although rare, ECD should be considered in the differential diagnosis of intratendinous masses.

Erdheim-Chester disease (ECD): Case report, clinical and basic investigations, and review of literature

BACKGROUND

Erdheim-Chester disease (ECD) is an uncommon aggressive, multisystem form of non-Langerhans' cell histocytosis, which was firstly reported by Jakob Erdheim and William chester in 1930. The disease pathological features encompass an aberrant multiplication, overproduction and accumulation of white blood cells called histiocytes within multiple tissues and organs. Herein, we present a case of ECD owing to the rarity of this disease (roughly 550 cases have been described in the literature to date).

METHODS

We discussed the clinical course, diagnostic evaluations, and the possible treatments. Our case was encountered in an Arab male in his 30's who has suffered from an ongoing bones pain for years.

RESULTS

At our rheumatologic department we compiled his recent medical history, which consisted of diagnosis of central diabetes insipidus, hyperprolactinemia and secondary hypogonadism along with the previously conducted laboratory evaluations and imaging which brought to our mind the possibility of an infiltrative disease such as ECD. The diagnosis of ECD was done based on the combinations of pathognomonic radiographic osteosclerosis, neuroimaging, bones biopsies along with a careful clinical evaluation. Given the protean clinical manifestations, interferon-α was considered as our first line treatment of ECD, consequently our patient improved noticeably.

CONCLUSION

Clinical presentation, imaging studies, distinctive pathological findings, followed by bone biopsy showed a non-Langerhans cell histiocytosis, supported by immunohistochemistry exams are essential for the diagnosis. Radiation therapy and Bisphosphonates in addition to cladribine, anakinra, infliximab and vemurafenib (BRAF Inhibitors) are currently advocated as promising second line treatment for patients whose response to interferon-α is unsatisfactory.

Acute Cardiac Tamponade in a 77-year-old Italian Woman with Erdheim-Chester Disease

Erdheim-Chester disease (ECD) is a non-Langerhans’ histiocytosisand a veryrare multisystemic disease of unknown aetiology, with skeletal involvement of the long bones and in more than 50% of cases with extraskeletal involvement. The disease was described in 1930 by the anatomopathologist Jakob Erdheim and his student William Chester. More than 500 cases have since been reported. We report the case of a 77-year-old Italian woman with ECD who was admitted to hospital for acute cardiac tamponade. The patient presented with simultaneous cutaneous, retro-orbital, skeletal, cerebral and cardiovascular manifestations and was successfully treated with corticosteroids followed by interferon.

Unusual presentation of Erdheim-Chester disease in a child with acute lymphoblastic leukemia

Erdheim-Chester disease (ECD) is an uncommon, non-familial, non-Langerhans cell histiocytosis, which involves skeletal system and soft tissue usually in middle aged and elderly patients. The characteristic radiologic features include bilateral, symmetric cortical osteosclerosis of the diaphyseal and metaphyseal parts of the long bones, or bilateral symmetrically abnormal intense ^99mTechnetium labelling of the metaphyseal-diaphyseal region of the long bones, and computed tomography scan findings of “coated aorta” or “hairy kidneys”. ECD in childhood with osteolytic lesion is extremely rare. We describe an unusual case with an expansile lytic bone lesion at presentation in a case of acute lymphoblastic leukemia.

Erdheim-Chester Disease with Emperipolesis: A Unique Case Involving the Heart

Histiocytosis is an uncommon disease characterized by excessive accumulation of histiocytes. Here, we report a rare case of non-Langerhans-cell histiocytosis in a 51-year-old woman who presented with severe symptoms of pericardial effusion. Radiologic investigation also detected multiple bone (lower limbs, vertebrae, ribs, and ilium) lesions. Resected pericardium showed abundant mono- or multi-nucleated non-foamy histiocytes (CD68⁺/CD163⁺/S-100⁺/CD1α⁻/langerin⁻) in a fibroinflammatory background. The histiocytes demonstrated emperipolesis of lymphocytes, a hallmark feature of Rosai-Dorfman disease (RDD). However, molecular analysis revealed a BRAF V600E mutation of the proliferating histiocytes, highlighting the neoplastic features frequently observed in another non-Langerhans-cell histiocytosis known as Erdheim-Chester Disease (ECD). We consider this case to be a unique presentation of ECD harboring some RDD-like cells with emperipolesis, but not a case of RDD with a BRAF mutation concerning its clinical manifestation (involvement of the heart and bones) and neoplastic features.