Long term morbidity and health related quality of life after multi-system Langerhans cell histiocytosis

Oral manifestation as the only sign of Langerhans cell histiocytosis: A case report

Key Clinical Message

The manifestations of Langerhans cell histiocytosis can be limited in the oral cavity, including gingival recession, tooth mobility, and bone destruction. Dentists play a crucial role in the early detection and management of these oral symptoms, which can significantly impact the overall prognosis and quality of life for patients with this serious disease.

Abstract

The hyperplastic activity of bone marrow can lead to excessive histocyte proliferation, called Langerhans cell histiocytosis (LCH). Based on the accumulation location, it has various organ involvement, including skin, bone, and so forth. Oral manifestations such as tooth involvement, bone lesions, mucosal ulcers, and periodontal problems can occur, and they might be the only manifestation of LCH. A subtle diagnosis is crucial and can be started with dental examinations. A 5-year-old girl was examined with the chief complaint of gingival recession with no pain, caries, or calculus. The clinical and radiographical assessment led to further immunohistochemical (IHC) evaluations. The diagnosis was LCH based on S-100 and cluster of differentiation 1a (CD1a) markers. LCH can involve different cells and tissues locally or generally. The early detection and treatment of LCH increase children's survival rate and quality of future life. Therefore, an accurate diagnosis is important among dentists. They must consider that abnormal mobility, gingival, or periodontal problems with no logical cause might warn about a latent problem. Sometimes extraction of loose teeth is not the end of treatment; it is the start of neglecting a serious disease.

Langerhans cell histiocytosis: promises and caveats of targeted therapies in high-risk and CNS disease

Langerhans cell histiocytosis (LCH) is a rare myeloid neoplasm driven by activating mutations in the MAPK pathway, most commonly BRAF-V600E and MAP2K1. It affects children and adults, with a wide spectrum of clinical presentations ranging from self-limited to multisystem (MS) life-threatening forms. LCH is defined by the accumulation of CD1a+/CD207+ cells in different organs, and patients with liver, spleen, or hematopoietic system involvement have a higher risk of mortality. Patients with neurodegeneration (ND) have devastating outcomes and are resistant to systemic therapies. MS-LCH is treated with risk-adapted therapy, but many patients require multiple salvage regimens that are myelosuppressive and expensive. MAPK inhibitors are increasingly being used, but most patients relapse upon discontinuation of therapy. Here, we review the management of central nervous system disease and how novel cerebrospinal fluid biomarkers might predict patients at high risk of ND who could benefit from early MAPK inhibition. Further, we discuss treatment strategies for refractory/relapsed (R/R) LCH, with a focus on MAPK inhibitors' efficacy and challenges (ie, the unknown): long-term toxicity in children, optimal duration, if they are curative, whether it is safe to combine them with chemotherapy, and their high price tag. Lastly, emerging strategies, such as the new panRAF inhibitor (Day 101) in patients with R/R LCH, ERK1/2 or CSF1R inhibition in patients with MEK1/2 inhibitor resistance, and targeting the microenvironment (checkpoint plus MEK inhibition) or senescent cells (mTOR or BCL-XL inhibitors) in R/R patients, are also examined.

Histiocytic disorders

The historic term 'histiocytosis' meaning 'tissue cell' is used as a unifying concept for diseases characterized by pathogenic myeloid cells that share histological features with macrophages or dendritic cells. These cells may arise from the embryonic yolk sac, fetal liver or postnatal bone marrow. Prior classification schemes align disease designation with terminal phenotype: for example, Langerhans cell histiocytosis (LCH) shares CD207+ antigen with physiological epidermal Langerhans cells. LCH, Erdheim-Chester disease (ECD), juvenile xanthogranuloma (JXG) and Rosai-Dorfman disease (RDD) are all characterized by pathological ERK activation driven by activating somatic mutations in MAPK pathway genes. The title of this Primer (Histiocytic disorders) was chosen to differentiate the above diseases from Langerhans cell sarcoma and malignant histiocytosis, which are hyperproliferative lesions typical of cancer. By comparison LCH, ECD, RDD and JXG share some features of malignant cells including activating MAPK pathway mutations, but are not hyperproliferative. 'Inflammatory myeloproliferative neoplasm' may be a more precise nomenclature. By contrast, haemophagocytic lymphohistiocytosis is associated with macrophage activation and extreme inflammation, and represents a syndrome of immune dysregulation. These diseases affect children and adults in varying proportions depending on which of the entities is involved.

Histiocytosis

Histiocytoses constitute a heterogeneous group of rare disorders, characterised by infiltration of almost any organ by myeloid cells with diverse macrophage or dendritic cell phenotypes. Histiocytoses can start at any age. Diagnosis is based on histology in combination with appropriate clinical and radiological findings. The low incidence and broad spectrum of clinical manifestations often leads to diagnostic delay, especially for adults. In most cases, biopsy specimens infiltrated by histiocytes have somatic mutations in genes activating the MAP kinase cell-signalling pathway. These mutations might also be present in blood cells and haematopoietic progenitors of patients with multisystem disease. A comprehensive range of investigations and molecular typing are essential to accurately predict prognosis, which can vary from spontaneous resolution to life-threatening disseminated disease. Targeted therapies with BRAF or MEK inhibitors have revolutionised salvage treatment. However, the type and duration of treatment are still debated, and the prevention of neurological sequelae remains a crucial issue.

Psychological features of adult patients with langerhans cell histiocytosis

BACKGROUND

The prevalence of psychological symptoms and the co-occurrence of substance abuse disorders in adult patients with Langerhans cell histiocytosis (LCH) has not been previously explored. We aimed to use validated scales to evaluate depression and anxiety symptoms experienced by adult LCH patients.

METHODS

In this cross-sectional study, all consecutive adult LCH patients seen at our national reference center between January 2012 and January 2013 were asked to complete the following instruments: the Hospital Anxiety and Depression scale (HADS); Barratt Impulsiveness Scale, Version 10 (BIS-10); and Cannabis Use Disorders Identification Test (CUDIT). Self-reported scores on these scales were used to determine the point prevalence of clinically significant psychological symptoms and substance use disorders in LCH patients. Patient profiles in terms of psychological features were assessed by principal component analysis including the HADS and BIS-10 instruments values, followed by hierarchical clustering. Fisher exact tests and Wilcoxon tests were used to examine the associations between disease-related parameters and high levels of anxiety and impulsivity.

RESULTS

Seventy-one adult LCH patients, mainly with pulmonary LCH (PLCH), completed the evaluations. Clinically significant anxiety and depression symptoms were reported by 22 (31%) and 4 (6%) subjects, respectively. Impulsivity was detected in 14% (10/71) of the patients. Seventeen percent (12/71) of the patients used cannabis on a regular basis, with 50% of these individuals (6/12) exhibiting scores consistent with cannabis use disorder. Three derived clusters of patients were identified in the principal component analysis; these patient clusters differed in successful weaning from tobacco at the time of evaluation (p = 0.03). In univariate analyses, isolated PLCH and the use of psychotropic treatments were statistically associated with clinically significant anxiety symptoms.

CONCLUSIONS

High levels of anxiety and impulsivity are common in adult patients with LCH. The consequences of these symptoms for the management of LCH patients warrant further evaluation.

Altered cerebral perfusion in children with Langerhans cell histiocytosis after chemotherapy

BACKGROUND AND PURPOSE

Children with Langerhans cell histiocytosis (LCH) may develop a wide array of neurological symptoms, but associated cerebral physiologic changes are poorly understood. We examined cerebral hemodynamic properties of pediatric LCH using arterial spin-labeling (ASL) perfusion magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A retrospective study was performed in 23 children with biopsy-proven LCH. Analysis was performed on routine brain MRI obtained before or after therapy. Region of interest (ROI) methodology was used to determine ASL cerebral blood flow (CBF) (mL/100 g/min) in the following bilateral regions: angular gyrus, anterior prefrontal cortex, orbitofrontal cortex, dorsal anterior cingulate cortex, and hippocampus. Quantile (median) regression was performed for each ROI location. CBF patterns were compared between pre- and posttreatment LCH patients as well as with age-matched healthy controls.

RESULTS

Significantly reduced CBF was seen in posttreatment children with LCH compared to age-matched controls in angular gyrus (P = .046), anterior prefrontal cortex (P = .039), and dorsal anterior cingulate cortex (P = .023). Further analysis revealed dominant perfusion abnormalities in the right hemisphere. No significant perfusion differences were observed in the hippocampus or orbitofrontal cortex.

CONCLUSION

Perfusion in specific cerebral regions may be consistently reduced in children with LCH, and may represent effects of underlying disease physiology and/or sequelae of chemotherapy. Studies that combine a formal cognitive assessment and hemodynamic data may further provide insight into perfusion deficits associated with the disease and the potential neurotoxic effects in children treated by chemotherapy.

Vemurafenib for Refractory Multisystem Langerhans Cell Histiocytosis in Children: An International Observational Study

PURPOSE

Off-label use of vemurafenib (VMF) to treat BRAFV600E mutation-positive, refractory, childhood Langerhans cell histiocytosis (LCH) was evaluated.

PATIENTS AND METHODS

Fifty-four patients from 12 countries took VMF 20 mg/kg/d. They were classified according to risk organ involvement: liver, spleen, and/or blood cytopenia. The main evaluation criteria were adverse events (Common Terminology Criteria for Adverse Events [version 4.3]) and therapeutic responses according to Disease Activity Score.

RESULTS

LCH extent was distributed as follows: 44 with positive and 10 with negative risk organ involvement. Median age at diagnosis was 0.9 years (range, 0.1 to 6.5 years). Median age at VMF initiation was 1.8 years (range, 0.18 to 14 years), with a median follow-up of 22 months (range, 4.3 to 57 months), whereas median treatment duration was 13.9 months (for 855 patient-months). At 8 weeks, 38 complete responses and 16 partial responses had been achieved, with the median Disease Activity Score decreasing from 7 at diagnosis to 0 (P < .001). Skin rash, the most frequent adverse event, affected 74% of patients. No secondary skin cancer was observed. Therapeutic plasma VMF concentrations (range, 10 to 20 mg/L) seemed to be safe and effective. VMF discontinuation for 30 patients led to 24 LCH reactivations. The blood BRAFV600E allele load, assessed as circulating cell-free DNA, decreased after starting VMF but remained positive (median, 3.6% at diagnosis, and 1.6% during VMF treatment; P < .001) and was associated with a higher risk of reactivation at VMF discontinuation. None of the various empirical therapies (hematopoietic stem-cell transplantation, cladribine and cytarabine, anti-MEK agent, vinblastine, etc) used for maintenance could eradicate the BRAFV600E clone.

CONCLUSION

VMF seemed safe and effective in children with refractory BRAFV600E-positive LCH. Additional studies are needed to find effective maintenance therapy approaches.

Systemic Histiocytosis (Langerhans Cell Histiocytosis, Erdheim-Chester Disease, Destombes-Rosai-Dorfman Disease): from Oncogenic Mutations to Inflammatory Disorders

PURPOSE OF REVIEW

Provide an overview of recent progress in decoding the pathogenesis and treatment of systemic histiocytoses.

RECENT FINDINGS

Advances in molecular techniques over the last few years, enabling the identification of several MAPK mutations in lesion histiocytes, have revolutionized our understanding of histiocytosis that led to a revised classification and new treatments. Since the 2010 discovery of the BRAF^V600E mutation in 57% of Langerhans cell histiocytosis (LCH) lesions, several other kinase mutations have been found, mostly in the MAPK pathway, and also in other key signaling pathways, in LCH, Erdheim-Chester Disease (ECD) and, less frequently, Destombes-Rosai-Dorfman disease (RDD). Those revolutionary breakthroughs enhanced our understanding of the pathogenesis of histiocytosis and led to trials with targeted therapies that demonstrated notable efficacy.

Evaluation and treatment of Langerhans cell histiocytosis patients with central nervous system abnormalities: Current views and new vistas

Central nervous system (CNS) involvement in Langerhans cell histiocytosis (LCH) can include mass lesions of the hypothalamic pituitary axis, choroid plexus, cerebrum, and cerebellum or magnetic resonance imaging (MRI) signal abnormalities of the cerebellum, pons, and basal ganglia. The term neurodegenerative (ND) CNS-LCH has been given to the MRI signal abnormalities and neurologic dysfunction, although initially patients may have no clinical symptoms. Standardized evaluations to better understand the natural history and response to therapy are needed. We propose guidelines for clinical, radiologic, and physiologic tests as a framework for developing the best methods of evaluation, which can then be tested in prospective treatment protocols.

Granulomatous Diseases Affecting Jaws

The common aspect of all granulomatous diseases is the typical form of chronic inflammatory response with distinct microscopic granulomas that are formed secondary to either definitive etiologic agents, like bacteria, fungal, or parasitic, or due to an unknown etiologic agent, such as trauma, autoimmune, or even neoplastic process. Although they can be histologically distinct, granulomatous diseases demonstrate a variety of clinical features that may not seem to be inflammatory. Two types of granulomas are typically encountered: foreign body granulomas and immune granulomas. The differences between the two types of granulomas lie in the pathogenesis.

Late outcomes in children with Langerhans cell histiocytosis

INTRODUCTION

Langerhans cell histiocytosis (LCH) is a rare disease with diverse clinical courses. Despite improvement in survival outcomes in the recent decades, sequelae of the disease remain a concern. This study aimed to provide information on the long-term outcomes in patients with LCH, particularly on the sequelae and any associated factors.

METHOD

Medical records of patients with diagnosis of LCH and being managed in our centre were retrospectively reviewed. Data on the courses of illness, mortality, intervention, types and time of late events were collected and analysed.

RESULTS

70 patients were included with a mean observation time of 12 years (median 10.7 years, range 1-31.3 years). Sequelae related to LCH were present in 56% (n=39), being more common in multisystem diseases and patients with reactivations. Prevalence of sequelae is as follows: orthopaedic related 27%, diabetes insipidus 19%, growth retardation 13%, cosmetic 10%, neurological 7%, hearing 7%, anterior pituitary hormone deficiency 7%, hepatobiliary 4% and ophthalmological 3%. Neurological sequelae could manifest even 10 years after initial diagnosis of LCH. Reactivations, presence of central nervous system (CNS) risk lesions and treatment with radiotherapy were associated with a higher rate of sequelae. The cumulative incidence of reactivation was 34%. Most reactivations occurred in the first 2.5 years after diagnosis.

CONCLUSION

Sequelae were common after LCH, although some were mild. Neurological sequelae could be particularly severe and debilitating. Vigilant long-term follow-up would be essential for optimising patient outcomes. Further studies on the prevention and treatment of CNS disease of LCH are warranted.

Histiocytoses: emerging neoplasia behind inflammation

Histiocytoses are disorders characterised by inflammation and the accumulation of cells derived from the monocyte and macrophage lineages, which results in tissue damage. Although they are often considered rare disorders with protean clinical manifestations, considerable advances in the understanding of their genetics have led to increased clinical recognition of these conditions, and fuelled further insights into their pathogenesis. In this Review, we describe insights into the cells of origin, molecular pathology, clinical features, and treatment strategies for some of the most common histiocytic disorders, including Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai-Dorfman disease. With the discovery of recurrent mutations affecting the mitogen-activated protein kinase and mTOR-AKT pathways in some of these histiocytoses, our understanding of these diseases has now evolved from the concept of a primary inflammatory condition to that of a clonal neoplastic disease. This understanding has led to the development of effective mechanism-based therapeutic strategies for patients with histiocytic diseases.

Langerhans cell histiocytosis: therapeutic strategy and outcome in a 30-year nationwide cohort of 1478 patients under 18 years of age

The French national cohort of children with Langerhans cell histiocytosis (LCH) has included 1478 patients since it was established in 1983. LCH therapeutic strategies substantially changed in 1998, so we have divided the cohort into two 15-year periods. Starting in 1998, therapy duration increased from 6 to 12 months, repeated induction therapy was performed in cases showing a poor response to the first induction with vinblastine and steroids, and refractory disease in a risk organ (RO+) was treated with cladribine and cytarabine. A total of 483 (33%) patients were enrolled before 1998, and 995 (67%) after 1998. Five-year survival was 96·6% (95% confidence interval: 95·4-97·5%) overall, improving from 92% pre-1998 to 99% post-1998 (P < 0·001 adjusted to disease extent). This change was supported by an increase in 5-year survival from 60% to 92% in the RO+ group. Survival was particularly associated with cladribine and cytarabine among refractory RO+ patients. Disease reactivation was slightly less frequent after 1998, due to better enrolment of single-system patients, extended therapy duration, and more efficient second-line therapy. The crude rates of endocrine and neurological sequelae (the most frequent sequelae) appeared to improve over time, but this difference was not observed when the analysis was stratified by disease extent.

Social/economic costs and health-related quality of life in patients with histiocytosis in Europe

OBJECTIVE

The aim of this study was to determine the economic burden from a societal perspective and the health-related quality of life (HRQOL) of patients with histiocytosis in Europe.

METHODS

We conducted a cross-sectional study of patients with histiocytosis from France, Germany, Italy, Spain, Bulgaria, the UK, and Sweden. Data on demographic characteristics, health resource utilisation, informal care, loss of labour productivity and HRQOL were collected from the questionnaires completed by patients or their caregivers. HRQOL was measured with the EuroQol 5-domain (EQ-5D) questionnaire.

RESULTS

A total of 134 patients (35 France, 32 Germany, 30 Italy, 24 Spain, 7 Bulgaria, 4 UK and 2 Sweden) completed the questionnaire. The average annual costs ranged from € 6832 to € 33,283 between countries, the year of reference being 2012. Estimated direct healthcare costs ranged from € 1698 to € 18,213; direct nonhealthcare costs ranged from € 2936 to € 17,622 and labour productivity losses ranged from € 1 to € 8855. The mean EQ-5D score for adult histiocytosis patients was estimated at between 0.32 and 0.85, and the mean EQ-5D visual analogue scale score was estimated at between 50.00 and 66.50.

CONCLUSION

The main strengths of this study lie in our bottom-up approach to costing and in the evaluation of histiocytosis patients from a broad perspective (societal costs). This type of analysis is very scarce in international literature for rare diseases in comparison with other illnesses. We conclude that histiocytosis patients incur considerable societal costs and experience substantial deterioration in HRQOL.

Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages

The histiocytoses are rare disorders characterized by the accumulation of macrophage, dendritic cell, or monocyte-derived cells in various tissues and organs of children and adults. More than 100 different subtypes have been described, with a wide range of clinical manifestations, presentations, and histologies. Since the first classification in 1987, a number of new findings regarding the cellular origins, molecular pathology, and clinical features of histiocytic disorders have been identified. We propose herein a revision of the classification of histiocytoses based on histology, phenotype, molecular alterations, and clinical and imaging characteristics. This revised classification system consists of 5 groups of diseases: (1) Langerhans-related, (2) cutaneous and mucocutaneous, and (3) malignant histiocytoses as well as (4) Rosai-Dorfman disease and (5) hemophagocytic lymphohistiocytosis and macrophage activation syndrome. Herein, we provide guidelines and recommendations for diagnoses of these disorders.

The presence of CXCR4+ CD1a+ cells at onset of Langerhans cell histiocytosis is associated with a less favorable outcome

PURPOSE

Langerhans Cell Histiocytosis (LCH) is a neoplastic disorder characterized by tissue accumulating CD1a⁺ histiocytes which frequently carry somatic mutations. Irrespective of mutation status, these LCH-cells display constitutively active kinases belonging to the MAPK pathway. We evaluated, in retrospect, the contribution of individual components of the MAPK-activating and chemotaxis-promoting TNF-CXCR4-CXCL12 axis to LCH manifestation and outcome.

EXPERIMENTAL DESIGN

CXCR4, CXCL12 and TNF protein expression was immunohistochemically analyzed in 70 LCH-affected biopsies. The presence of CXCR4⁺CD1a⁺ cells in peripheral blood (PB) and/or bone marrow (BM) samples was evaluated by flowcytometry in 13 therapy-naive LCH-patients.

RESULTS

CXCL12 was detected in 68/70 (97%) biopsies. CXCR4⁺LCH-cells were present in 50/70 (71%) biopsies; their presence was associated with higher levels of intralesional TNF. Circulating CD1a⁺CXCR4⁺ cells were detected in 4/13 (31%) therapy-naïve LCH-patients which displayed BRAF^V600E (2/4), MAP2K1 (1/4) or no (1/4) mutations in their tissues. These CD11c co-expressing CD1a⁺CXCR4⁺cells migrated to CXCL12 in chemotaxis assays. Lesional CXCR4⁺LCH-cells were detected in 18/20 cases who presented with LCH manifestation at multiple sites and in 5/23 (22%) patients who developed additional lesions after initially presenting with a single lesion. The CXCR4 status at onset proved to be an independent risk factor for LCH reactivation in multivariate analysis (odds ratio 10.4, p = 0.034).

CONCLUSIONS

This study provides the first evidence that CXCR4 is involved in the homing and retention of LCH-cells in CXCL12-expressing tissues and qualifies CXCR4 as a candidate prognostic marker for less favorable disease outcome.

Langerhans cell histiocytosis in children with congenital anomalies: a population-based record linkage study

BACKGROUND

The etiology of Langerhans cell histiocytosis (LCH), a rare cancer-like disorder of the immune system, is largely unknown although a genetic component has been suggested based on familial cases, and reports of chromosome instability and genetic mutation. Associations between various cancers and congenital anomalies have been reported and although congenital anomalies have been noted in children with LCH only one study to date has reported their frequency. An association between congenital anomalies and LCH may suggest a common etiological pathway, in particular, a genetic pathway.

METHODS

Data from two coterminous registries in the same geographic region were used. All cases of LCH on the Northern Region Young Persons Malignant Disease Register diagnosed between 1985 and 2010 were cross-matched with live-born cases of congenital anomaly registered by the Northern Congenital Abnormality Survey.

RESULTS

A total of 819,890 children and young people were born during 1985 to 2008. Of these, 13,799 (1.7%) had a congenital anomaly and 39 (0.005%) were diagnosed with LCH. Three LCH cases were identified among those with congenital anomalies, all three of whom had congenital heart disease. The relative risk of LCH for those with a congenital anomaly, compared with those without, was 4.87 (95% confidence interval, 1.50-15.81; p = 0.03).

CONCLUSION

LCH was associated with congenital anomaly in a small but statistically significant number of patients, raising the possibility of a common genetic pathway in some cases.

A rare disorder mimics otitis media: Langerhans cell histiocytosis of the temporal bone in a child with interstitial pulmonary fibrosis

Langerhans cell histiocytosis (LCH) is a rare disease ranging from a benign to a rapidly fatal condition affecting young children predominantly, and is characterized by an abnormal clonal proliferation of Langerhans cells. We report a case of a 3-year-old child presenting with a 1-year history of otorrhea and otorrhagia followed by a 6-month history of postauricular swelling in the right ear. Imaging demonstrated a large mass of organized tissue. A biopsy was conducted, and the diagnosis of LCH was confirmed by histopathological and immunohistochemical examination. The child was treated with a 12-month course of vinblastine chemotherapy with prednisolone. No clinical evidence of recurrence was noticed after 3 years of follow-up. This rare case highlights the importance for otolaryngologists to keep LCH in mind for differential diagnosis in very young patients with symptoms and signs suggestive of acute mastoiditis or chronic otitis media.

Langerhans cell histiocytosis: 23 years’ paediatric experience highlights severe long-term sequelae

Purpose

To review the presentation and outcome of patients with Langerhans cell histiocytosis attending The Royal Hospital for Sick Children, Glasgow over a 23-year period.

Method

Thirty-one children were diagnosed with Langerhans cell histiocytosis between January 1990 and December 2012. Retrospective information from medical records was gathered on age at diagnosis, presenting symptoms, classification of disease, treatment and long-term outcome.

Results

There were 17 boys and 14 girls; median age at diagnosis 2 years 9 months (interquartile range: 1 year 6 months to 4 years 4 months). Eleven were below 2 years and two were below 6 months of age at diagnosis. Eighteen (58%) children had single system disease of which four were multifocal; 13 (42%) had multisystem disease. Seventeen children improved with conservative treatment. Fourteen required steroids and dual agent chemotherapy; three required further chemotherapy. One child died. Two children had successfully treated relapses. Ten developed diabetes insipidus, seven were growth hormone deficient, two suffered from hypothyroidism and one panhypopituitarism. Median follow-up of the cohort was 8 years 10 months (interquartile range: 5 years 5 months to 12 years 7 months).

Conclusion

Langerhans cell histiocytosis is a rare disease in infants and young children, with a variable course ranging from self-limiting to life threatening. In very young children (under 2 years of age), multisystem disease is more common, requiring intensive chemotherapy and lifelong follow-up. Lasting sequelae were identified in over a third of patients, including endocrine dysfunction, hearing difficulties, neurological and psychological problems.

Blood spotlight on Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease affecting people of any age, with widely variable clinical manifestations and different outcomes. The precise chain of events driving lesional granuloma formation has remained elusive for many years. There is evidence for inherited predisposition to and derangement of apoptosis and inflammation in lesional dendritic cells. Recently somatic BRAF(V600E) mutation in myeloid precursor dendritic cells was associated with the more aggressive form of the disease, although the same mutation in a more differentiated dendritic cell might drive a less aggressive disease. Whether this picture convincingly put LCH in the field of myeloid neoplasm remains to be determined. Altogether, these findings suggest that future therapeutic strategy might incorporate a screening of this genetic mutation for high-risk patients potentially suitable for target therapy.

Langerhans cell histiocytosis (LCH): guidelines for diagnosis, clinical work-up, and treatment for patients till the age of 18 years

These guidelines for the management of patients up to 18 years with Langerhans cell histiocytosis (LCH) have been set up by a group of experts involved in the Euro Histio Net project who participated in national or international studies and in peer reviewed publications. Existing guidelines were reviewed and changed where new evidence was available in the literature up to 2012. Data and publications have been ranked according to evidence based medicine and when there was a lack of published data, consensus between experts was sought. Guidelines for diagnosis, initial clinical work-up, and treatment and long-term follow-up of LCH patients are presented.

Prosthodontic treatment of a class IV ACP PDI patient, with Langerhans cell histiocytosis (LCH)

Langerhans cell histiocytosis (LCH) is a disease of unknown etiology with a frustrating and unpredictable course. Surviving adult patients suffering from the multisystem type of the disease present with problems in most organs. This article presents the oral rehabilitation of a 28-year-old patient, with multisystem sequelae that included the oral cavity, classifying him as a Class IV American College of Prosthodontists Prosthodontic Diagnostic Index patient. A 5-year course of treatment is analyzed, starting from merely replacing missing teeth with a removable partial denture. The second stage of prosthetic rehabilitation included replacement of the removable prosthesis with fixed partial dentures. The final and most important aspect of treatment was the 2-year follow-up, when the patient presented with no problems or adverse effects. The purpose of this presentation is to offer an insight to prosthodontic treatment possibilities for patients suffering from multisystem LCH and to show the value of a "team approach" to achieving a positive outcome.

Head and neck manifestation and prognosis of Langerhans' cell histiocytosis in children

OBJECTIVE

To appreciate the several head and neck manifestations of Langherans' cell histiocytosis (LCH) in children and their multidisciplinary management and outcome.

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

Clinical reports of 42 patients with LCH treated in the Departments of Paediatric Haematology, Paediatric Oncology and Paediatric Otorhinolaryngology of a tertiary care center were analyzed. Only cases where the disease was localized to the head and neck were considered. The age at diagnosis, gender, clinical presentation, extension of disease as well as response to treatment and outcome were recorded from the charts of each of these patients.

RESULTS

Of the 42 patient charts reviewed, 31 (73.8%) presented with head and neck localization. 10 of these had an exclusive head and neck presentation. Multisystem LCH was mostly found in infants under 3-year-old (mean age: 2-year-old), and bony manifestations in older. All treatments delivered to patients were well-tolerated and the evolution good.

DISCUSSION AND CONCLUSION

Head and neck involvement is known to be very frequent in LCH. There is no consensus about treatment but authors highlight that all teams in charge of patients presenting with LCH agree to remain as conservative as possible. For solitary large lesions looking like a tumor which resection could result in functional or cosmetic morbidity, it would be important to get first a biopsy. For multisystemic LHC, therapeutic trials with chemotherapy agents still in process should increase the rate of success.

High incidence of hearing loss in long-term survivors of multisystem Langerhans cell histiocytosis

BACKGROUND

Ear involvement in the acute phase of Langerhans cell histiocytosis (LCH) is commonly seen and well documented, but the long-term sequelae are less well described, particularly in relation to hearing loss.

METHODS

We investigated 40 patients with biopsy-proven multisystem LCH >5 years from the end of treatment, using detailed audiological assessment and CT/MRI imaging of the petrous temporal bones.

RESULTS

The incidence of ear involvement in the acute phase of disease was 70%. Fifteen of the 39 patients tested (38%) had residual permanent hearing loss at long-term follow-up.

CONCLUSIONS

The incidence of hearing loss is much higher than has previously been reported in LCH, and may reflect a referral bias of young (<2 years) and more complex patients to our tertiary centre. However, the hearing loss appears to be highly specific to this patient group when compared to other long-term survivors of childhood cancers, probably due to the propensity of LCH to involve the ears. We therefore recommend audiology testing as an important part of long-term follow-up for patients with multisystem LCH.

Health-related quality of life, cognitive functioning and behaviour problems in children with Langerhans cell histiocytosis

BACKGROUND

This study was designed to evaluate generic and disease-specific health-related quality of life (HRQoL), cognitive functioning and behaviour problems of children with Langerhans Cell Histiocytosis (LCH). Furthermore, we investigated which medical determinants and social demographic factors were predictive for HRQoL, cognitive functioning and behavioural problems.

PROCEDURE

In this cross-sectional case-control study 24 children ranging from 7 to 17 years of age were administered a HRQoL questionnaire, cognitive tests and behaviour ratings. In addition, a disease-specific HRQoL measure was developed and tested. Results were compared to a reference group consisting of healthy peers and to proxy-ratings by parents and teachers.

RESULTS

Children with LCH reported a lower physical HRQoL than the reference group (P <or= 0.05). Children older than 12 reported lower HRQoL scores. Scores on the disease-specific HRQoL questionnaire were lower than on the generic measure used. Performances on cognitive tests varied widely, short term visual memory was most affected. Twenty-five percent of the children follow special education. According to parents and teachers, children with LCH had more internalising behaviour problems (i.e., anxiety and depression), compared to the instrument norms. Children with Diabetes Insipidus, other CNS involvement and children who have had chemotherapy had more cognitive and behaviour problems than the other children with LCH.

CONCLUSIONS

HRQoL is affected in children with LCH, especially in older children. Children with LCH show more internalising problem behaviour than their peers. Teachers are important additional informants about behaviour problems.

Langerhans cell histiocytosis: a review of the current recommendations of the Histiocyte Society

Langerhans cell histiocytosis is a rare proliferative disorder where pathologic Langerhans cells accumulate in a variety of organs. Historically, the nomenclature regarding this entity has been confusing because the disease had been subcategorized simply based upon the different clinical manifestations. In the following article, we summarize the current recommendation of the Histiocyte Society regarding the classification, evaluation, prognosis, and treatment of Langerhans cell histiocytosis.

Paediatric neuroradiological aspects of Langerhans cell histiocytosis

Langerhans cell histiocytosis, previously known as histiocytosis X, is a complex disease consisting of three entities that are all characterized by a proliferation of the Langerhans cell. The clinical course is variable and ranges from a solitary lytic bone or skin lesion with complete remission to a multisystem disorder with possible lethal outcome. The clinical suspicion can be increased based on radiological findings that are important criteria in defining the extent of the disease involvement. A biopsy is often necessary for establishing the final diagnosis. The lytic craniofacial bone lesions are the most common craniospinal abnormality in Langerhans cell histiocytosis. Abnormalities in the hypothalamic-pituitary region are the most frequent manifestations, often accompanied with diabetes insipidus as the presenting symptom. A range of different central nervous system abnormalities can be recognized. It is important to be able to recognize the extensive spectrum of neuroradiological abnormalities in order to arrive at the diagnosis. Neuroimaging plays an even more important role in assessing the response to treatment or possible relapse.

Reactivation and risk of sequelae in Langerhans cell histiocytosis

OBJECTIVE

To evaluate disease reactivation in patients with Langerhans cell histiocytosis (LCH) and its impact on adverse sequelae.

MATERIALS AND METHODS

A retrospective evaluation of 300 patients diagnosed with LCH between 1987 and 2002 with complete response to initial treatment was performed.

RESULTS

Mean age at diagnosis was 5.3 years. With a mean follow-up of 4.8 years, reactivation of the disease occurred in 29.7% (89/300) of the patients, with two or more reactivations in 34.8% (31/89) of those. Reactivation occurred in 17.4, 36.8, 46.5, and 53.5% of the patients with single-system unifocal disease (Group A: 161 patients), single-system multifocal disease (Group B: 53 patients), multi-system disease without (Group C: 58 patients), and with (Group D: 28 patients) risk-organ involvement, respectively. The differences between the incidence rates of Groups A and B (P < 0.0004), A and C (P < 0.0001), and A and D (P < 0.0001) were highly significant. The most common reactivation sites involved were bone, middle ear, and skin; reactivation was rare in risk organs (9.5%). The median time between initial complete response and the first reactivation episode was 1 year for Group A, 1.3 years for Group B, and 9 months for Groups C and D. Most reactivation episodes (88%) occurred within the first 2 years of follow-up. Adverse sequelae were recognized in 242/300 patients: 71% (49/69) of patients with and 25.4% (44/173) without reactivations developed these adverse sequelae (P < 0.0001), respectively. Sites most commonly showing sequelae were bone, middle ear, and hypothalamus (Diabetes Insipidus).

CONCLUSIONS

Incidence of reactivation correlates with the stage of the disease at diagnosis. Incidence of sequelae correlates with the occurrence of reactivations.