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

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

Erdheim-Chester Disease with Renal Mass Presentation: Report of the First Case From Palestine and a Review of the Literature.

BACKGROUND Erdheim-Chester disease (ECD), a form of non-Langerhans-cell histiocytosis, is extremely rare. The mean age of individuals with ECD is in their 50s. Histiocytic infiltration of vital organ systems is a potential cause of substantial morbidity, which is associated with the multisystemic form of ECD. This report presents the first case of ECD with renal abnormalities in Palestine. CASE REPORT A 54-year-old woman with no medical or surgical history presented with 6 months of bilateral flank pain with no radiation or fever. A physical examination revealed only bilateral flank pain. Urine tests showed microhematuria. Laboratory test results showed increased serum creatinine levels (1.21 mg/dL) and microcytic anemia. A CT scan revealed significant multi-organ abnormalities, including renal abnormalities with a hairy kidney sign, pericardial effusion, and an osteolytic lesion of the spine. The hairy kidney sign is pathognomonic for ECD, so the renal mass was biopsied to confirm the diagnosis. The biopsy showed foamy histiocytes, lymphocytes, and plasma cells. Foamy histiocytes were CD68-positive and negative for S100, CD1a, and HMB45. PAx5 and CD3 immunostaining showed T-predominant B-lymphocyte mixtures. CONCLUSIONS In the setting of systemic symptoms and imaging abnormalities such as presence of the hairy kidney sign, pericardial effusion, and osteolytic lesion of the spine, it is necessary to examine the possibility of ECD and proceed with a biopsy for confirmation. This is the first case in Palestine to be reported and the second case worldwide with a renal mass as an atypical presentation.

An effective treatment in Erdheim Chester disease: vemurafenib: a case report.

BACKGROUND: Erdheim Chester disease (ECD) is a rare disease with multisystemic involvement in the group of non-langerhans cell histiocytosis. Although nearly 100 years have passed since its definition, the number of cases reported all over the world is below 1000. In addition to the rarity of the disease, low awareness seems to play a role in this. CASE PRESENTATION: 47-year-old white caucasian women patient who presented to our clinic with symptoms of weakness-fatigue as well as increasing pain in the knees and ptosis in the left eye. Result of the patient's bone biopsy, ECD was considered pathologically and BRAF V600E mutation was shown molecularly. After presenting the clinical, laboratory and other examination results of the case, the dramatic response seen with targeted therapy will be discussed. CONCLUSIONS: BRAF V600E mutation is frequently seen in ECD. Vemurafenib plays an active role in targeted therapy.

A new phenotype of myorhythmia: Oculofacial myorhythmia in a patient with Erdheim Chester disease.

Oculofacial myorhythmia (OFM) is a movement disorder characterized by slow, rhythmic, and repetitive movement that affects the periorbital and perioral muscles. This abnormal movement is classified as a tremor and is highly suggestive of brainstem lesions. Unlike the oculomasticastory myorhythmia, the oculofacial pattern has rarely been reported to date. We present a patient diagnosed with Erdheim Chester disease who two years after the diagnosis developed an oculofacial myorhythmia. We additionally provide a pathological framework based on evolutionary changes on neuroimaging which could explain the appearance of this very rare movement disorder. No cases of OFM have been described in patients with ECD to date. To our knowledge we are reporting the first case of oculofacial myorhythmia secondary to Erdheim Chester disease. To conclude, oculofacial myorhytmia could be a late-onset clinical manifestation of ECD with brainstem involvement.

Novel paraneoplastic mechanism for cerebellar ataxia in Erdheim-Chester disease.

We report a case of BRAF-mutation positive Erdheim-Chester disease presenting with a cerebellar ataxia. This is the first such case to be reported without structural MRI abnormalities but with a single intrathecally produced oligoclonal band. Now that the histiocytoses have been recharacterised as neoplastic, we speculate that the mechanism of the ataxia in our case is paraneoplastic. We highlight the importance of searching for BRAF mutations in this disease, as their presence leads to effective personalised treatments.

Erdheim-Chester disease misdiagnosed as meningioma of the pontocerebellar angle: A case report and review of literature.

Erdheim-Chester Disease (ECD) is a rare non-Langerhans form of systemic histiocytosis of unknown etiology with multiple organ involvement. It most commonly affects the long bones, lungs, heart, retroperitoneum, eyes, and kidneys and less commonly the brain and spinal cord. Although there are very few cases of supratentorial ECD mimicking intracranial meningioma reported in literature, to the best of our knowledge, there are no reports on ECD mimicking infratentorial pontocerebellar angle meningioma. The present study reports a case of ECD mimicking pontocerebellar angle meningioma. This study aimed to emphasize the importance of systemic evaluation using a multidisciplinary approach as well as the need for considering ECD as a differential diagnosis of xanthomatous meningioma.

Histiocitosis / Histiocytosis

Las histiocitosis son un grupo de enfermedades raras que se caracterizan por la inflamación y acúmulo de células derivadas de los monocitos y macrófagos en diferentes tejidos. La clínica es muy variable, desde formas leves con afectación de un solo órgano a formas multisistémicas graves que pueden comprometer la vida. Su diagnóstico se basa en la clínica, hallazgos radiológicos y la anatomía patológica. Se recomienda realizar una biopsia del tejido afecto en todos los casos dado que puede tener implicaciones terapéuticas. En este sentido, durante la última década se han identificado mutaciones en tejido afecto que condicionan activación de la vía de las proteínas cinasas activadas por mitógenos (MAPK/ERK) y fosfatidilinositol 3 kinasa (PI3K/AKT), en proporción variable, en función del tipo de histiocitosis. En esta revisión nos centramos fundamentalmente en la histiocitosis de células de Langerhans, la enfermedad de Erdheim-Chester y la enfermedad de Rosai-Dorfman (AU)

Histiocytosis is a group of rare diseases characterized by inflammation and accumulation of cells derived from monocytes and macrophages in different tissues. The symptoms are highly variable, from mild forms with involvement of a single organ to severe multisystem forms that can be life compromising. The diagnosis of histiocytosis is based on the clinic, radiological findings and pathological anatomy. A biopsy of the affected tissue is recommended in all cases as it may have therapeutic implications. During the last decade, some mutations have been identified in the affected tissue that condition activation of the MAPK/ERK and PI3K/AKT pathway, in a variable proportion depending on the type of histiocytosis. In this review we mainly focus on Langerhans Cell Histiocytosis, Erdheim-Chester Disease and Rosai-Dorfman Disease (AU)

Erdheim-Chester disease with bilateral orbital masses and multi-systemic symptoms: two case reports.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare histiocytic disorder characterized by multisystem xanthogranulomatous infiltration by lipid-laden histiocytes. We report two cases of ECD involving the orbit and describe their clinicopathologic factors, treatments, and prognosis. One was a rare case of ECD complicated with primary thrombocytosis. CASE PRESENTATION: This study describes two patients with bilateral orbital ECD. Both presented with proptosis and visual loss; imaging findings showed bilateral intraorbital masses. Both had different degrees of systemic symptoms (pleural effusion, pericardial effusion, ascites, and heart failure) before the ocular symptoms and did not find the cause before ophthalmic tumor resection and pathological biopsy. The diagnosis of ECD was confirmed after pathological biopsy and detection of BRAFV600E mutation. Patient 2 also with primary thrombocytosis and had a CALR mutation as well as the BRAFV600E mutation. Both patients were recommended to receive targeted therapy. Patient 1 refused targeted therapy for financial reasons and was discharged after local radiotherapy only. The patient had no light perception in either eye and no improvement in systemic symptoms. Patient 2 began targeted treatment after diagnosis and reached the discharge criteria 2 weeks later. He is in good condition at present, but unfortunately, his eyesight has not improved because of the irreversible damage to his visual function. CONCLUSION: ECD is easily misdiagnosed and missed because of its rarity and diverse clinical manifestations. Orbital involvement is common in ECD, and surgery is the most frequently employed approach. Despite the surgical resection is not curative, its significance lies in biopsy to establish diagnosis and/or surgical debulking to relieve mass effect, minimizing further impairment of visual function. Targeted therapy is the most effective treatment for patients with a positive BRAF mutation gene. Evaluation of a concomitant myeloid neoplasm is also critical before initiating targeted therapies for refractory ECD.

An Unusual Case of Erdheim Chester Disease (ECD) with Knee Pain: A Case Report.

Background: Erdheim Chester disease (ECD) is a rare, non-Langerhans cell histiocytosis of unknown etiology that occurs in multiple organs. The clinical characteristics of ECD are unknown, making it difficult to diagnose. Case presentation: A 61-year-old woman presented with left knee pain and contracture. She had recent medical problems such as recurrent urinary tract infection, pericardial effusion, and pleural effusion. Simple radiography and magnetic resonance imaging of the knee revealed an osteosclerotic lesion. Under suspicion of malignancy, other radiologic modalities were performed, but there were no significant results showing malignancy. A bone biopsy of the knee lesion led to a final diagnosis of ECD. The patient was treated with systemic steroids and was ultimately tried on PEG-interferon. Conclusion: This report describes an unusual presentation of ECD involving the skeletal system and multiple extraskeletal organs. Owing to its non-specific nature, ECD was notably difficult to diagnose. Therefore, if a patient has knee pain and other multiorgan presentations without malignancy, clinicians should suspect ECD.

Erdheim-Chester Disease: A Case Report of BRAF V600E-Negative, MAP2K1-Positive ECD Diagnosed by Blood Next-Generation Sequencing Assay and a Brief Literature Review.

Erdheim-Chester disease (ECD) is a rare type of non-Langerhans cell histiocytosis. However, its prevalence has increased significantly the past few years due to increased awareness about the disorder, and 1500 cases have been reported worldwide. It is often a multisystemic disease with skeletal, cardiovascular, urologic, renal, retroperitoneal, pulmonary, endocrine, cutaneous, and neurologic involvement. MAPK pathway mutations, such as BRAF activating and MAP2K1 mutations, play a key role in its pathogenesis. In addition to the characteristic clinical, radiological, and histopathological findings, identifying underlying mutations helps diagnose and treat patients with highly effective targeted therapies such as BRAF and MEK inhibitors. We report a case of a man, aged 55 years, with an extensive and prolonged course of an unexplained multisystemic disease, later diagnosed with BRAF V600E-negative and MAP2K1-positive ECD on cell-free DNA testing. Additionally, we review common clinical manifestations, mutations, diagnoses, and targeted therapies for ECD.

Case report of a patient with Erdheim-Chester disease presenting with neuro-endocrine symptoms and negative for BRAF mutation.

RATIONALE: Erdheim-Chester disease (ECD) is a rare progressive disease affecting multiple systems. It has recently been recognized as a neoplastic disease following the discovery of activating mutations in the MAPK pathway. There are several striking signs of ECD, such as the long bone involvement, as well as the hairy kidney appearance on computed tomography scan. It is rare for ECD to manifest neurological symptoms. Central nervous system involvement is a strong prognostic factor and independent predictor of death. ECD is characterized by the overproduction and accumulation of foamy histiocytes and Touton's giant cells in various tissues and organs. ECD is a multisystem disorder in which any organ may be affected. PATIENT CONCERNS: This case report describes a 57-year-old woman with headaches and ataxia as the first clinical manifestation, without characteristic bone pain, but with delayed enuresis. In addition to the renal involvement, this patient had rarer splenic involvement. DIAGNOSES: The imaging presentation of this patient was similar to that of a "multiple meningiomas". A combination of clinical, imaging and pathology for the diagnosis of ECD. INTERVENTIONS: Patients were given INF-α therapy. OUTCOMES: Fortunately, the patient responded well to INF-α treatment. LESSONS: ECD patient with neuro-endocrine symptoms.

[Histiocytosis]. / Histiocitosis.

Histiocytosis is a group of rare diseases characterized by inflammation and accumulation of cells derived from monocytes and macrophages in different tissues. The symptoms are highly variable, from mild forms with involvement of a single organ to severe multisystem forms that can be life compromising. The diagnosis of histiocytosis is based on the clinic, radiological findings and pathological anatomy. A biopsy of the affected tissue is recommended in all cases as it may have therapeutic implications. During the last decade, some mutations have been identified in the affected tissue that condition activation of the MAPK/ERK and PI3K/AKT pathway, in a variable proportion depending on the type of histiocytosis. In this review we mainly focus on Langerhans Cell Histiocytosis, Erdheim-Chester Disease and Rosai-Dorfman Disease.

Neurological Manifestations of Histiocytic Disorders.

PURPOSE OF REVIEW: Histiocytic disorders, including Erdheim-Chester disease (ECD), Langerhans cell histiocytosis (LCH), and Rosai-Dorfman disease (RDD), are rare neoplasms that may present with a spectrum of neurologic involvement. Diagnostic delay is common due to heterogeneity in presentation and challenging pathology. RECENT FINDINGS: Recent advances in the treatment of these diseases targeted towards mutations in the MAP kinase pathway have led to an improved prognosis in these patients with neurologic involvement. It is critical for clinicians to have a high index of suspicion to allow for early targeted treatment and optimize neurologic outcomes. A systematic approach to diagnosis is presented in this article to allow for accurate diagnosis of these rare diseases.

Rare cause of pericardial effusion: 'Erdheim-Chester disease'.

This report details the case of a woman in her 50s who presented with symptoms of congestive heart failure and raised inflammatory biochemical markers. Her investigations included an echocardiogram, which revealed a large pericardial effusion and a subsequent CT-thorax/abdomen/pelvis showing extensive retroperitoneal, pericardial and periaortic inflammation and soft-tissue infiltration. Genetic analysis of histopathological samples detected a V600E or V600Ec missense variant within codon 600 of the BRAF genewith BRAF variants, confirming the diagnosis of Erdheim-Chester disease (ECD).The patient's clinical management involved several treatments and interventions with input from a variety of clinical specialties. This included the cardiology team for pericardiocentesis, the cardiac surgical team for pericardiectomy due to recurrent pericardial effusions and finally the haematology team for further specialist treatment with pegylated interferon and consideration of BRAF inhibitor therapy. The patient became stable following treatment with significant improvement in her heart failure symptoms. She remains under regular joint cardiology and haematology team follow-up. The case highlighted the importance of using a multidisciplinary approach to best manage the multisystem involvement of ECD.

A case of Erdheim-Chester disease with the BRAF V600E mutation diagnosed via endoscopic sinus surgery.

Erdheim-Chester disease is characterized by the infiltration of foamy histiocytes in tissues. Lesional tissue biopsy is recommended to confirm diagnosis and establish the BRAF mutational status. A 52-year-old man presented to our hospital with hydronephrosis. Computed tomography showed enhancement of soft shadows around the left renal pelvis transition area and the aorta. He was treated with prednisolone 0.2 mg/kg for 1 year; however, no improvement was observed. 18Fluorodeoxyglucose-positron emission tomography/computed tomography revealed increased fluorodeoxyglucose uptake in various body parts, including the maxillary sinuses, indicative of Erdheim-Chester disease. He refused further examination, and the maxillary sinus lesions were treated with antibiotics and intranasal steroids, but no improvement was observed. Two years later, he underwent biopsy with endoscopic sinus surgery of the maxillary sinus, which showed the highest increase in fluorodeoxyglucose uptake on repeat 18fluorodeoxyglucose-positron emission tomography/computed tomography. Endoscopic findings showed only nonspecific inflammatory findings, but pathological findings revealed the proliferation of cells with abundant foamy cytoplasms. Sufficient tumor volume was available to perform PCR for BRAF V600E mutation analysis, which was positive and resulted in a diagnosis of Erdheim-Chester disease with the BRAF V600E mutation. This is the first case of a patient with Erdheim-Chester disease with the BRAF V600E mutation identified in a sinus lesion. Endoscopic sinus surgery biopsy of the paranasal sinuses was considered to contribute to the histological and genetic diagnosis of Erdheim-Chester disease, particularly following the notable increase in fluorodeoxyglucose uptake.

Successful treatment of non-Langerhans cell histiocytosis with the MEK inhibitor trametinib: a multicenter analysis.

Erdheim-Chester disease (ECD) and Rosai-Dorfman disease (RDD) are rare non-Langerhans cell histiocytoses (non-LCHs), for which therapeutic options are limited. MAPK pathway activation through BRAFV600E mutation or other genomic alterations is a histiocytosis hallmark and correlates with a favorable response to BRAF inhibitors and the MEK inhibitor cobimetinib. However, there has been no systematic evaluation of alternative MEK inhibitors. To assess the efficacy and safety of the MEK inhibitor trametinib, we retrospectively analyzed the outcomes of 26 adult patients (17 with ECD, 5 with ECD/RDD, 3 with RDD, and 1 with ECD/LCH) treated with orally administered trametinib at 4 major US care centers. The most common treatment-related toxicity was rash (27% of patients). In most patients, the disease was effectively managed at low doses (0.5-1.0 mg trametinib daily). The response rate of the 17 evaluable patients was 71% (73% [8/11] without a detectable BRAFV600E achieving response). At a median follow-up of 23 months, treatment effects were durable, with a median time-to-treatment failure of 37 months, whereas the median progression-free and overall survival were not reached (at 3 years, 90.1% of patients were alive). Most patients harbored mutations in BRAF (either classic BRAFV600E or other BRAF alterations) or alterations in other genes involved in the MAPK pathway, eg, MAP2K, NF1, GNAS, or RAS. Most patients required lower than standard doses of trametinib but were responsive to lower doses. Our data suggest that the MEK inhibitor trametinib is an effective treatment for ECD and RDD, including those without the BRAFV600E mutation.

Erdheim-Chester Disease Involving the Left Uterine Adnexa: Mimicking an Ovarian Carcinoma Clinically.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis (LCH) that results in multiorgan disease involving the skin, bones, lungs, and kidneys. Female reproductive system manifestation of ECD was rare. Herein, we report a case of ECD involving the left ovary and fallopian tube. A 69-year-old woman presented with abdominal pain for 20 days. Magnetic resonance imaging revealed a solid and cystic mass on the left pelvic cavity. Histological examination revealed ovarian and fallopian tube infiltration by abundant histiocytes, with single small nuclei and foamy cytoplasm, reactive small lymphocytes, and plasma cells. Based on histopathological and immunohistochemical findings of positivity for CD68, CD163, and BRAF V600E and negativity for CD1α and S100, the molecular finding of BRAF V600E mutation, the patient was diagnosed with ECD. Positron emission tomography examination did not reveal any other lesions. The patient recovered well 12 months after surgery without any treatment. ECD involving the left fallopian tube and ovary was rare and needed to be differentiated from LCH, Rosai-Dorfman disease (RDD), juvenile xanthogranuloma (JXG), IgG4+-related disease (IgG4+RD), and metastatic signet ring cell carcinoma.