Pattern and course of single-system disease in Langerhans cell histiocytosis data from the DAL-HX 83- and 90-study

Molecular Mutations in Histiocytosis: A Comprehensive Survey of Genetic Alterations

Histiocytosis represents a group of uncommon disorders characterized by the abnormal accumulation of specialized immune cells, such as macrophages, dendritic cells, or monocyte-derived cells, in various tissues and organs. Over 100 distinct subtypes have been documented, each displaying a broad spectrum of clinical presentations and histological characteristics. Till today, histiocytosis has been addressed through a combination of chemotherapy, radiotherapy, and surgery, with varying responses from individual patients. Due to its atypical symptoms, it has been prone to misdiagnosis. Advances in our understanding of the cellular and molecular aspects of these conditions are paving the way for improved diagnostic methods and targeted therapies. Researchers have extensively investigated various mutations in patient samples. However, no paper has yet provided a comprehensive summary of the collective analysis of mutations and pathways. Hence, this paper consolidates research efforts that specifically concentrate on gene mutations identified in patient samples of different subtypes of histiocytosis. These insights are essential for developing targeted therapies and improving diagnosis. Further, it provides potential insights to enhance the development of more effective therapeutic approaches for rare diseases.

[Bone tumors in children and adolescents]

Osseous lesions are rare; however, their incidence is increased in childhood and adolescence. The spectrum of osseous processes in this age group is limited, with benign lesions being much more prevalent than malignant tumors. For the differential diagnosis, it is essential to have in-depth knowledge of the more frequent bone diseases in children and adolescents. The current review presents these diseases based on the morphologic approach of the WHO classification, including giant cell-rich and cystic lesions, chondrogenic and bone-forming lesions [7]. Small round cell sarcomas which are now summarized in a separate chapter of the WHO classification have been described previously [12, 20].

Craniofacial involvement in Langerhans cell histiocytosis: A review of 44 cases at a single medical center

BACKGROUND

Craniofacial bones are the most commonly involved site of Langerhans cell histiocytosis (LCH). The main purpose of this study was to clarify the relation between subsites of craniofacial bone and clinical presentation, treatment modalities, outcomes, and permanent consequences (PCs) in patients with LCH.

METHODS

Forty-four patients diagnosed with LCH involving the craniofacial region presenting at a single medical center during 2001-2019 were collected and divided into four groups: single system with unifocal bone lesion (SS-LCH, UFB); single system with multifocal bone lesions (SS-LCH, MFB); multisystem without risk organ involvement (MS-LCH, RO-); and multisystem with risk organ involvement (MS-LCH, RO+). Data including demographics, clinical presentation, treatments, outcomes, and the development of PC were retrospectively reviewed.

RESULTS

Temporal bone (66.7% versus 7.7%, p = 0.001), occipital bone (44.4% versus 7.7%, p = 0.022), and sphenoid bone (33.3% versus 3.8%, p = 0.041) involvement were more common in SS-LCH, MFB than they were in SS-LCH, UFB. No difference of reactivation rate was noted among the four groups. The most common PC is diabetes insipidus (DI), reported in 9 of the 16 (56.25%) patients with PC. The single system group was reported with the lowest incidence of DI (7.7%, p = 0.035). The reactivation rate was also higher in patients with PC (33.3% versus 4.0%, p = 0.021) or DI (62.5% versus 3.1%, p < 0.001).

CONCLUSION

An increased risk of multifocal or multisystem lesions was associated with temporal bone, occipital bone, sphenoid bone, maxillary bone, eye, ear, and oral involvement, which may indicate poor outcomes. Longer follow-up may be indicated if there is the presence of PC or DI due to the high risk of reactivation. Therefore, multidisciplinary evaluation and treatment according to risk stratification are vital for patients diagnosed with LCH involving the craniofacial region.

Comparison of whole-body DW-MRI with 2-[18F]FDG PET for staging and treatment monitoring of children with Langerhans cell histiocytosis

PURPOSE

To assess and compare the diagnostic accuracy of whole-body (WB) DW-MRI with 2-[18F]FDG PET for staging and treatment monitoring of children with Langerhans cell histiocytosis (LCH).

METHODS

Twenty-three children with LCH underwent 2-[18F]FDG PET and WB DW-MRI at baseline. Two nuclear medicine physicians and two radiologists independently assessed presence/absence of tumors in 8 anatomical areas. Sixteen children also performed 2-[18F]FDG PET and WB DW-MRI at follow-up. One radiologist and one nuclear medicine physician revised follow-up scans and collected changes in tumor apparent diffusion (ADC) and standardized uptake values (SUV) before and after therapy in all detectable lesions. 2-[18F]FDG PET results were considered the standard of reference for tumor detection and evaluation of treatment response according to Lugano criteria. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of WB DW-MRI at baseline were calculated, and the 95% confidence intervals were estimated by using the Clopper-Pearson (exact) method; changes in tumor SUVs and ADC were compared using a Mann-Whitney U test. Agreement between reviewers was assessed with a Cohen's weighted kappa coefficient. Analyses were conducted using SAS software version 9.4.

RESULTS

Agreement between reviewers was perfect (kappa coefficient = 1) for all analyzed regions but spine and neck (kappa coefficient = 0.89 and 0.83, respectively) for 2-[18F]FDG PET images, and abdomen and pelvis (kappa coefficient = 0.65 and 0.88, respectively) for WB DW-MRI. Sensitivity and specificity were 95.5% and 100% for WB DW-MRI compared to 2-[18F]FDG PET. Pre to post-treatment changes in SUVratio and ADCmean were inversely correlated for all lesions (r: -0.27, p = 0·06) and significantly different between responders and non-responders to chemotherapy (p = 0.0006 and p = 0·003 for SUVratio and ADCmean, respectively).

CONCLUSION

Our study showed that WB DW-MRI has similar accuracy to 2-[18F]FDG PET for staging and treatment monitoring of LCH in children. While 2-[18F]FDG PET remains an approved radiological examination for assessing metabolically active disease, WB DW-MRI could be considered as an alternative approach without radiation exposure. The combination of both modalities might have advantages over either approach alone.

Intensification of treatment with vinca alkaloid does not improve outcomes in pediatric patients with Langerhans cell histiocytosis: results from the JPLSG LCH-12 study

Chemotherapy with cytarabine, vincristine (VCR), and prednisolone has achieved low mortality rates in pediatric patients with Langerhans cell histiocytosis (LCH). However, relapse rates remain high, making event-free survival (EFS) rates unsatisfactory. A nationwide clinical trial, LCH-12, tested a modified protocol in which the early maintenance phase was intensified with increasing dosages of VCR. Patients newly diagnosed with multifocal bone (MFB) or multisystem (MS) LCH and aged < 20 years at diagnosis were enrolled between June 2012 and November 2017. Of the 150 eligible patients, 43 with MFB were treated for 30 weeks and 107 with MS LCH were treated for 54 weeks. One patient with MS LCH died of sepsis during the induction phase. The 3-year EFS rates among patients with MFB LCH, risk organ (RO)-negative MS LCH, and RO-positive MS LCH were 66.7% (95% confidential interval [CI], 56.5-77.0%), 66.1% (95% CI 52.9-76.4%), and 51.1% (95% CI 35.8-64.5%), respectively, similar to previously observed rates. EFS rates were significantly lower in patients with disease activity scores > 6 than in those with scores ≤ 6. The strategy that included more intense treatment with VCR was not effective. Other strategies are required to improve outcomes in patients with pediatric LCH.

Whole-body magnetic resonance imaging for staging Langerhans cell histiocytosis in children and young adults

INTRODUCTION

Radiographic skeletal survey (R-SS) is the standard imaging technique for the initial staging of Langerhans cell histiocytosis (LCH). Whole-body magnetic resonance imaging (WB-MRI) has been proposed as an effective, radiation-free alternative.

METHODS

We prospectively assessed patients with LCH followed at three tertiary centers in Italy and Austria. Two national study protocols were independently designed, and data were then pooled to increase the power of their findings. R-SS and WB-MRI were performed at diagnosis and repeated at the follow-up to confirm the nature of the identified lesions and to study their evolution.

RESULTS

Data from 67 patients were analyzed (52 from Italy and 15 from Austria). Compared to R-SS, WB-MRI identified 29 additional skeletal lesions in 14 patients (including two false-positive lesions). Two skeletal lesions were detected at R-SS and missed at WB-MRI (false negative). Per-lesion sensitivity rates were 78.6% (95% CI: 71.0-85.9) for R-SS and 98.4% (95% CI: 94.4-99.8) for WB-MRI, respectively. Based on WB-MRI findings, six patients would have been upstaged to a higher risk class than staging with R-SS.

CONCLUSIONS

WB-MRI had a significantly higher detection rate for skeletal lesions compared to R-SS. Clinical and radiology expertise is required to avoid upstaging and overtreatment.

Biomodulatory therapy induces durable remissions in multi-system Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is rare hematological neoplasia originating from the aberrant proliferation of CD207-positive dendritic cells. Refractory multi-system LCH is difficult to treat necessitating the continuous development of different salvage therapies. At our medical center, eleven patients (age 11 months to 77 years) with multi-system LCH were treated on a compassionate use basis with metronomic biomodulation therapy (MBT) involving the daily oral application of low-dose trofosfamide, etoricoxib, pioglitazone and low-dose dexamethasone. Overall, four patients including two heavily pretreated pediatric patients achieved ongoing complete remission. Moreover, partial disease remission was observed in three patients, and four patients attained stable disease. MBT demonstrated high activity against multi-system LCH even in patients, refractory to multiple systemic chemotherapies. Further confirmation of efficacy should be systematically evaluated in prospective trials.

Incidence, Clinical Features, and Outcomes of Langerhans Cell Histiocytosis in the United States

Langerhans cell histiocytosis (LCH) is a disorder with highly diverse clinical manifestations. We explored if age, sex, race, organ system involved, and therapy approaches determine patient survival in the era of modern treatments. LCH patient data reported to the Surveillance, Epidemiology, and End Results (SEER) program in 2010-2016 (n=1282; age: 0 to 100 y) was analyzed. Age-specific LCH incidence flattening to a low level suggests an age cutoff for pediatric patients of 20 years. The overall survival probability is lower for patients 21 to 100 years old ( P <0.0001), irrespective of sex and race. The commonest sites involved in the 0- to 20-year age group were bone, skin, and bone marrow; this shifted to lung, bone, and skin as the commonest disease sites in patients 21 to 100 years of age. The treatments applied differed between age groups, as younger versus older patients were more likely to receive chemotherapy-based treatment (48.4% vs. 17%; P <0.0001). There also was a trend toward nonwhite versus white patients being less likely to receive chemotherapy-based treatment (31.7% vs. 38.2%; P =0.067). Whereas there are treatment disparities related to LCH patient age and perhaps race, patient age is the strongest predictor of survival, with patients 21 to 100 years of age with lung, lymph node, skin, and bone marrow disease having the worst outcomes ( P <0.0001).

Percutaneous CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histocytosis: a three institution retrospective analysis

PURPOSE

The aim of this study is to evaluate the safety and effectiveness of CT-guided corticosteroid injection for the treatment of osseous Langerhans cell histiocytosis (LCH) in a multi-institutional study.

MATERIALS AND METHODS

This IRB-approved study included patients from three institutions. We retrospectively reviewed clinical, procedural, and imaging data for corticosteroid injections performed to treat osseous LCH. Location of the lesion, lesion maximum dimension and volume, corticosteroid type and dose, and time interval between injection and change in lesion size/volume and symptoms were recorded. Generalized estimating equations (accounting for multiple lesions per subject) were used to evaluate the association between predictors (dose, maximum lesion dimension, and lesion volume) and outcomes (time to partial and complete radiographic resolution, and time to pain control). This analysis was adjusted by anatomic site.

RESULTS

Forty corticosteroid injections were performed in 36 patients (20 (56%) females, and 16 (44%) males, ages 12 ± 11 (2-57) years). Mean lesion maximum dimension was 3.2 ± 1.7 cm, and volume was 10 ± 17 cm³. Imaging and clinical follow-up were available for 22/40 (55%) and 34/40 (85%) of injections, respectively. All lesions responded to corticosteroid injection. Times to partial and complete imaging resolution were 13 ± 9 and 32 ± 13 weeks, respectively, and time to pain resolution was 22 ± 14 weeks. There were no complications.

CONCLUSION

CT-guided corticosteroid injection is a safe and effective treatment for LCH. Pain resolution was achieved in all patients and imaging did not show progressive disease in any of the patients.

Manifestation of Langerhans cell histiocytosis in the oral cavity: The authors’ experience

Background. Langerhans cell histiocytosis is a rare reactive proliferative disorder marked by excess proliferation and accumulation of mononuclear phagocytes in tissues and organs. Usually, organs and systems where Langerhans cells are normally found are involved. Lesions may be limited to one system and be single- or multisite, or many systems may be involved. The etiology is not fully known. According to one of the hypotheses, immune dysfunction due to exuberant response to an unknown antigen may be the cause. The most common clinical symptoms include skin lesions, bone pain, exophthalmos, and enlarged lymph nodes, affecting the liver and spleen. Gingivitis, pocket granulation tissue, ulceration of the gingival papilla, alveolar bone atrophy leading to loosening and loss of teeth are observed in the oral cavity. The aim of the study was to determine the type and incidence of oral manifestations in patients diagnosed with Langerhans cell histiocytosis.

Methods. We evaluated patients’ medical records to obtain data on the children’s age at diagnosis, sex, the form of Langerhans cell histiocytosis, clinical picture (systemic and local oral symptoms), and radiological findings. Dental examinations (clinical and radiological) were performed to assess oral mucosa and periodontal tissues, and medical records were analyzed for the course and treatment of histiocytosis.

Results. The analysis included the medical records of 43 patients with Langerhans cell histiocytosis. Oral lesions in the form of gingivitis, pathological tooth mobility, and expansion of alveolar mandibular bone were observed in 7 patients. Conclusions. Langerhans cell histiocytosis may be accompanied by maxillary, gingival, and mucosal lesions.

Hepatobiliary and Gastrointestinal Involvement in Langerhans Cell Histiocytosis-Spectrum of Three Cases

Langerhans cell histiocytosis (LCH) is a rare group of disorder, due to clonal neoplastic proliferation of dendritic cells in the bone marrow expressing a Langerhans cell phenotype. 1 This disease particularly affects the pediatric age group and young adults and often presents with skin rashes, lung infiltrates, and bone lesions. It can also manifest with endocrine dysfunction and hematopoietic disorders. Involvement of gastrointestinal tract is very rare. Herein, we present a spectrum of three cases with gastrointestinal involvement.

Additive Prognostic Impact of Gastrointestinal Involvement in Severe Multisystem Langerhans Cell Histiocytosis

OBJECTIVE

To evaluate the prognostic impact of gastrointestinal involvement on the survival of children with Langerhans cell histiocytosis (GI-LCH) registered with the international clinical trials of the Histiocyte Society.

STUDY DESIGN

This was a retrospective analysis of 2414 pediatric patients registered onto the consecutive trials DAL-HX 83, DAL-HX 90, LCH-I, LCH-II, and LCH-III.

RESULTS

Among the 1289 patients with single-system LCH, there was no single case confined to the GI tract; 114 of 1125 (10%) patients with multisystem LCH (MS-LCH) had GI-LCH at initial presentation. GI-LCH was significantly more common in children aged <2 years at diagnosis (13% vs 6% in those aged >2 years; P < .001) and in those with risk organ involvement (15% vs 6% in those without risk organ involvement; P < .001). The 5-year overall survival (OS) in patients without risk organ involvement was excellent irrespective of GI disease (98% vs 97% in patients with GI-LCH; P = .789). In patients with risk organ involvement, the 5-year OS was 51% in 70 patients with GI-LCH vs 72% in 394 patients without GI-LCH (P < .001).

CONCLUSIONS

GI-LCH has an additive unfavorable prognostic impact in children with MS-LCH and risk organ involvement. The emerding need for more intensive or alternative treatments mandates prospective evaluation.

PET Imaging for Hematologic Malignancies

Hematologic malignancies are a broad category of cancers arising from the lymphoid and myeloid cell lines. The 2016 World Health Organization classification system incorporated molecular markers as part of the diagnostic criteria and includes more than 100 subtypes. This article focuses on the subtypes for which imaging with positron emission tomography/computed tomography (PET/CT) has become an integral component of the patient's evaluation, that is, lymphoma and multiple myeloma. Leukemia and histiocytic and dendritic cell neoplasms are also discussed as these indications for PET/CT are less common, but increasingly seen in clinic.

Adult-onset perianal Langerhans cell histiocytosis presenting as pruritus ani: a case report and review of the literature

Background

Langerhans cells belong to the histiocytic system and give rise to two tumors: Langerhans cell histiocytosis and Langerhans cell sarcoma. Clinical aggressiveness and degree of atypia distinguish the two neoplasms. Langerhans cell histiocytosis can infiltrate a single or multiple organ systems and particularly affects bone, skin, and lymph nodes. Perianal cutaneous Langerhans cell histiocytosis is a rare condition in adults, with 15 cases reported in the literature.

Case

We present the case of a 50-year-old hispanic man who presented with a 9-month history of pruritus ani and a personal history of diabetes insipidus. Punch biopsy confirmed a lesion of Langerhans cells origin but could not exclude Langerhans cell sarcoma because of limited sample size. An additional biopsy was planned as well as a positron emission tomography scan to determine the extent of disease spread. While the patient failed to follow up for repeat biopsy, the positron emission tomography scan was performed and was negative for metastatic disease. A stable perianal lesion of Langerhans cell histiocytosis with benign clinical features in a 50-year-old male despite lack of treatment is extremely rare and has not been described in the literature so far. Here, we review the presentation and workup of patients with Langerhans cell histiocytosis, review the relevant literature, and discuss treatment planning.

Conclusion

Perianal Langerhans cell histiocytosis is rare, and there should be a high index of suspicion with chronic or new perianal lesions, especially in a patient with a history of diabetes insipidus. It is also important to consider the patient’s full clinical course when it is not possible to reach a definitive pathological diagnosis before management.

Central diabetes insipidus developing in a 6-year-old patient 4 years after the remission of unifocal bone Langerhans cell histiocytosis

A six-year-old boy was referred with a one-and-a-half months history of polyuria and polydipsia. At the age of two, he had a single lytic bone lesion in his femoral head, diagnosed as Langerhans cell histiocytosis (LCH) by biopsy at another hospital. As no other affected organs were detected and the affected bone lesion was self-limited, he was not followed up afterward and was doing well. He was diagnosed with diabetes insipidus (DI) by confirming hypernatremia (Na: 148 mEq/l) with hyperosmolar serum (s-Osm 298 mOSM/kg) and inappropriately diluted urine (u-Osm 205 mOSM/kg). His polyuria and polydipsia improved dramatically using the perioral diuretic hormone, and other pituitary functions were not impaired. Magnetic resonance imaging revealed an enlarged pituitary stalk. Sensitive and specific biomarkers of germ cell tumors, including alpha-fetoprotein, placental alkaline phosphatase, and β-hCG in the cerebrospinal fluid, were not detected, indicating relapse of LCH. Genetic analysis revealed a BRAF V600E mutation in the primary bone lesion. We recommend systematic follow-up of patients with a history of LCH, even non-CNS single-system single-site disease, especially with BRAF V600E mutation.

LCH of the Scapula in a 2-Year-Old Masquerading as an ABC: A Case Report and Literature Review

We describe a unique case of Langerhans Cell Histiocytosis (LCH) arising in the scapula of a 2-year old male child masquerading as an aneurysmal bone cyst (ABC) at clinical presentation and on imaging. Scapular involvement is only occasionally noted in LCH cases. Solitary bone involvement in our patient’s age group is uncommon in LCH without multi-organ involvement. Careful pathologic examination and immunohistochemistry was crucial in establishing this diagnosis due to the presence of a solitary lesion with fluid-fluid levels.

Adult pulmonary Langerhans cell histiocytosis revealed by central diabetes insipidus: A case report and literature review

Langerhans cell histiocytosis (LCH) is a rare systemic and heterogeneous disease secondary to proliferation and diffuse infiltration of immature CD1a-positive dendritic cells, also known as Langerhans cells. LCH affects predominantly paediatric patients and is rarely diagnosed in adulthood. Despite its worldwide prevalence, most reported cases are found in the Japanese population. There is no consensus regarding treatment strategy due to the low incidence of this disease and the diversity of symptoms that appear. An integrative literature review was conducted based on the PubMed database using MeSH terms 'Langerhans', 'histiocytosis' and 'adult'. The present report describes a case of a successfully treated LCH-induced central diabetes insipidus (uncommon presentation in adult patients) as well as an updated review of current evidence published on this matter.

Clinical outcomes of childhood Langerhans cell histiocytosis in Taiwan: A single-center, 20-year experience

BACKGROUND/PURPOSE

The Taiwan Pediatric Oncology Group (TPOG) initiated two consecutive protocols for treating pediatric patients with Langerhans cell histiocytosis (LCH) since 1994. However, the results have not been analyzed and reported. This study aimed to investigate the survival outcomes of childhood LCH at the National Taiwan University Hospital over the past 20 years.

METHODS

Treatment of pediatric patients with LCH according to TPOG protocols at the National Taiwan University Hospital began in 1994. During 1994-2003, patients were treated using the TPOG LCH-94 protocol. After 2003, patients were treated using the TPOG LCH-2003 protocol. Clinical data of these patients were obtained retrospectively by reviewing electronic medical records. Patients were followed up until July 31, 2018.

RESULTS

Fifty-three newly diagnosed pediatric patients with LCH were treated at National Taiwan University Hospital during 1994-2015. Twenty-nine (54.7%) were treated with the TPOG LCH-94 protocol, and 24 (45.3%) were treated with the TPOG LCH-2003 protocol. The 5-year event-free survival and overall survival rates were 96.2 ± 2.6% standard error (SE) and 98.1 ± 1.9% (SE), respectively. Overall survival and 5-year event-free survival between patients treated with the TPOG LCH-94 and TPOG LCH-2003 protocols showed no significant difference. Multisystem, liver, or spleen diseases were associated with significantly bad survival outcomes. Among at-risk-organ involvement in LCH, liver involvement was an independent factor for poor prognosis.

CONCLUSION

Clinical outcomes of children with LCH in Taiwan was good. The results of this study may help in the better classification of risk grouping for protocol designs in the future.

Skeletal involvement in children with Langerhans cell histiocytosis: healing, complications, and functional outcome

Introduction: Skeletal involvement in children with Langerhans cell histiocytosis (LCH) is a common feature of the disease. Several options for the treatment of these skeletal lesions have been reported. We describe our experience in the treatment of skeletal involvement of LCH in this retrospective case series study, entailing anatomic distribution, pattern of healing, skeletal deformities, and functional outcome of skeletal LCH. Methods: A retrospective analysis was conducted for patients diagnosed with LCH and having skeletal lesions in the period between 2007 and 2015. Out of a total of 229 cases, 191 (83.4%) had skeletal involvement. Bone healing was divided into partial and complete based on the size of lesion and cortical changes in plain radiograph. Skeletal deformities were serially measured. Time to pain control, resumption of weight bearing, and the final functional status of the patient were reviewed. Results: The mean age at presentation was 4.4 years (3 m–14.8 y) and the mean follow-up period was 53.3 months (0.2–120.7). After screening of skeletal and extra-skeletal lesions, 59 patients (31%) had M-S (Multisystem) LCH and 132 (69%) had S-S (Single system) LCH. Unifocal bone lesions were found in 81 (42.5%) patients, and multifocal bone lesions in 110 patients (57.5%). Single or multiple bone lesions were found in the craniofacial bones in 152 patients (79.5%), femur in 19 patients, (10%), ribs in 18 patients (9.4%), spine in 15 patients (8.1%), pelvis in 14 patients (7.3%), scapula in 8 patients (4.1%), humerus in 6 (3.1%), clavicle in 6 patients (3.1%), tibia in 3 patients (1.5%), radius in 3 patients (1.5%), and the ulna in 2 patients (1%) patients. No lesions were found in the fibula, hand, or foot. Out of all skeletal lesions, 179 (93.7%) patients were treated either medically or conservatively and 12 patients (6.2%) were treated surgically. The mean time to complete healing was 5.2 months (2–12). Skeletal complications included: pathologic fractures (9 vertebra plana, 5 long bone, 1 iliac bone), deformities (9 thoracolumbar kyphosis, 2 cervical spine subluxations, 2 coxa vara deformity of the proximal femur and one flattening of iliac bone). Conclusion: Non-operative treatment can lead to adequate bone healing in few months period. Partial or complete remodeling of bone deformities can be observed without surgical correction. However, surgical intervention might be indicated when cervical spine affection may lead to instability and subsequent neurological affection. Functional impairment is rarely caused by skeletal lesions in LCH.

A Case of Multi-System Langerhans Cell Histiocytosis with Local Invasion of the Orbital Apex

Langerhans cell histiocytosis (LCH) is characterised by tissue destruction caused by the abnormal proliferation of pathogenic dendritic cells. We report a rare case of multi-system LCH with local invasion of the orbital apex. A 56-year-old woman suffered from a decrease of visual acuity in the left eye caused by central scotoma and the limitation of eye movement in all directions. Magnetic resonance imaging revealed an enhanced lesion in the left orbital apex, suggesting optic nerve compression. She had been diagnosed with eosinophilic granuloma 24 years previously. Two weeks after the current presentation, we admitted the patient for optic canal and orbital apex decompression and subtotal tumour resection. Histopathological analysis confirmed the diagnosis of LCH. Post-surgical treatment with low-dose cytarabine was initiated for the residual tumour. However, it was ceased because of myelosuppression-induced pyelonephritis. After surgery, the central scotoma disappeared on day 5 and eye movement palsy resolved by 6 months. After the cessation of cytarabine, she has received low-dose steroid therapy for 2 years with no recurrence. Early surgical intervention with low-dose steroid therapy can lead to recovery of visual acuity and resolve eye movement palsy in patients with lesions of the orbital apex caused by multi-system LCH.

Langerhans cell histiocytosis in children: History, classification, pathobiology, clinical manifestations, and prognosis

Langerhans cell histiocytosis (LCH) is an inflammatory neoplasia of myeloid precursor cells driven by mutations in the mitogen-activated protein kinase pathway. When disease involves the skin, LCH most commonly presents as a seborrheic dermatitis or eczematous eruption on the scalp and trunk. Evaluation for involvement of other organ systems is essential, because 9 of 10 patients presenting with cutaneous disease also have multisystem involvement. Clinical manifestations range from isolated disease with spontaneous resolution to life-threatening multisystem disease. Prognosis depends on involvement of risk organs (liver, spleen, and bone marrow) at diagnosis, particularly on presence of organ dysfunction, and response to initial therapy. Systemic treatment incorporating steroids and cytostatic drugs for at least one year has improved prognosis of multisystem LCH and represents the current standard of care.

Outcome of children with Langerhans cell histiocytosis and single-system involvement: A retrospective study at a single center in Shanghai, China

BACKGROUND

This is a descriptive review of the clinical patterns and outcomes of children with Langerhans cell histiocytosis and single-system involvement (SS-LCH) treated at Shanghai Children's Medical Center.

PROCEDURE

60 evaluable newly diagnosed patients (37 boys, 23 girls) with a median age of 3.9 years (range: 0.3-15.3 years) and histiopathology-confirmed SS-LCH were enrolled from 2010 to 2014. All patients received systemic chemotherapy using either the DAL HX-83 or LCH-II protocol as determined by the physician.

RESULTS

Bone was the most frequently affected organ (56/60, 93.3%). Of the 56 patients suffering from SS-bone disease, 35 (62.5%) had unifocal disease and 21 (37.5%) had multifocal disease. CNS-risk lesions were seen in nine patients (16.1%, 9/56) at diagnosis. Thirty-two patients were treated with the LCH-II protocol and 28 received the DAL HX-83 protocol. No patient received intralesional steroid injection at the time of surgery. CNS-risk lesion correlated with an inferior event-free survival (EFS) for patients with bone disease (62.5 ± 17.1% vs. 90.7 ± 4.5%; p = 0.039). The difference in the 5-year EFS between patients with unifocal and multifocal SS-bone LCH did not reach the statistical significance (93.8 ± 4.3% vs. 75.0 ± 9.7%; p = 0.074). No deaths were observed, leading to a 5-year OS of 100% in the present cohort of patients. Permanent consequences and secondary malignancies were not observed but were also limited by short follow-up.

CONCLUSIONS

Optimal therapy for patients with SS-bone LCH has not been established. Less toxic therapeutic approaches should be considered for these patients and tested in prospective trials.

Cutaneous Langerhans cell histiocytosis presenting with hypopigmented lesions: Report of two cases and review of literature

Langerhans cell histiocytosis is a rare group of disorders that results from the abnormal proliferation and accumulation of dendritic-derived cells in various organs of the body, such as the skin and bones. Hypopigmented macules are a rare cutaneous presentation of Langerhans cell histiocytosis that may pose a diagnostic dilemma when no other findings of Langerhans cell histiocytosis are present at the time of examination. We present 2 cases of the hypopigmented variant of Langerhans cell histiocytosis, including a case with histopathologic features of regression, and a review of the literature. These cases highlight the importance of including Langerhans cell histiocytosis in the differential diagnosis of an infant with hypopigmented macules and papules.

Fever and Skin Involvement at Diagnosis Predicting the Intractable Langerhans Cell Histiocytosis: 40 Case-Series in a Single Center

Langerhans cell histiocytosis (LCH) occurs as a clonal disease with enigmatic immune responses. LCH patients occasionally present with fever, although the significance remains elusive. We investigated the predicting factors for developing intractable disease of refractory and/or reactivated LCH. In total, 40 pediatric LCH patients managed in Kyushu University from 1998 to 2014 were enrolled. The medical records were analyzed retrospectively. Sixteen patients suffered from multisystem (MS) LCH involving risk organs (ROs) (n=4) or not (n=12). In total, 24 patients had single-system LCH affecting bone (multi n=8, single n=13), skin (n=2), or lymph node lesions (n=1). Eight patients had the intractable disease of 7 MS or 1 multibone LCH. Two patients died from MS LCH with or without RO involvement. Ten patients showed persistent fever (>38°C) at onset. Intractable cases had fever, RO and skin involvement, leukocytosis, coagulopathy, microcytic anemia, higher levels of soluble interleukin-2 receptor and C-reactive protein, more frequently at diagnosis. Multivariate analysis indicated that fever and skin lesions at diagnosis were independently associated with the intractability (odds ratio: fever, 35.5; 95% confidence interval, 3.0-1229.1; skin lesions, 24.6; 95% confidence interval, 1.9-868.7). Initial fever and skin involvement might predict the development of intractable and fatal-risk LCH even without the RO involvement.

Clinical course of the bony lesion of single-system single-site Langerhans cell histiocytosis - Is appropriate follow-up sufficient treatment?

BACKGROUND

Langerhans cell histiocytosis (LCH) is categorized into three types, which include single-system single-site (SS-s), single-system multiple-site (SS-m) and multisystem (MS). The most commonly affected site in LCH is bone, and the bony lesion of SS-s LCH has a good prognosis. The bony lesion of SS-s LCH has been thought to regress spontaneously. Although treatments such as curettage, direct injection of corticosteroids, and chemotherapy have been performed, regular follow-up is the first line of treatment for the bony lesion of SS-s LCH. For preventing orthopedic sequelae, strict and appropriate follow-up should be performed, but the appropriate period and method of follow-up has not yet been established.

METHODS

In the present study, we retrospectively analyzed a series of 7 cases of patients with SS-s LCH with a bony lesion treated in the Department of Orthopedic Surgery at Kagoshima University Hospital (Kagoshima, Japan) from 2006 to 2015.

RESULTS

The bony lesion regressed spontaneously in all patients. Factors such as location, size, preoperative C-reactive protein (CRP) value, standardized uptake (SUV) value of positron emission tomography (PET), age, sex and direct steroid injection were not related to the clinical course. Temporary expansion of the lesion occurred in 3 patients and a temporary worsening of pain occurred in 1 patient during the follow-up period. These events occurred within 6 weeks after biopsy.

CONCLUSION

Careful follow-up and the use of an appropriate orthosis can lead to a good clinical course for the bony lesion of SS-s LCH. Future research should seek to determine the appropriate follow-up period.

A 12-Month-Old Healthy Girl with a New Oral Ulcer and Chronic Diaper Rash

A 12-month-old healthy girl presented with a chronic diaper rash. Physical examination demonstrated crusting of the scalp, erythematous papules with surrounding petechiae on the lower abdomen, and an intraoral palatal ulcer. Further imaging demonstrated bone involvement. Histopathologic examination of involved skin and the intraoral ulcer demonstrated epithelioid histiocytes with “coffee bean-shaped” nuclei, staining positive for CD1a and langerin by immunohistochemistry, consistent with Langerhans cell histiocytosis (LCH). LCH is a disease entity of unknown etiology characterized by histiocytic proliferation that most commonly presents in young children. The cutaneous findings of LCH include a seborrheic dermatitis-like and/or red-brown papular eruption. Intraoral examination is crucial as oral mucosal and maxillofacial skeletal disease can also be seen in LCH. When a child presents with a recalcitrant seborrheic dermatitis-like eruption or chronic diaper rash, the clinician should be alerted to the possibility of LCH. Timely recognition and diagnosis of LCH is important for oncologic referral, evaluation, and treatment.

Langerhans Cell Histiocytosis: A Diagnostic Challenge in the Oral Cavity

Background

Langerhans cell histiocytosis (LCH) is a rare disorder of the reticuloendothelial system with unknown etiology. This report aims to present a case of LCH with diffuse involvement of the oral cavity and to raise awareness of the distinguishing features of this diagnostically challenging entity.

Case Report

A 26-year-old male patient presented with complaints of teeth mobility, intense pain, and difficulty in chewing. Intraoral and radiological examinations revealed generalized gingival hyperplasia and severe teeth mobility with widespread alveolar bone loss. Periodontal therapy was performed with no significant improvement. An incisional biopsy revealed Langerhans cells and positive reaction to S-100 and CD1, and the patient was diagnosed with LCH. The patient underwent systemic chemotherapy with vinca alkaloids and corticosteroids. Regression of gingival lesions, as well as significant decrease in mobility of the remaining teeth and severity of pain, was achieved during 12 months of follow-up.

Conclusion

The rarity and variable system involvement of LCH necessitate a multidisciplinary approach be carried out for accurate diagnosis, effective treatment, and an uneventful follow-up. Awareness of oral manifestations of LCH may aid clinicians greatly in reducing morbidity and mortality associated with this debilitating condition.

Usual and Unusual Manifestations of Familial Hemophagocytic Lymphohistiocytosis and Langerhans Cell Histiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) and Langerhans cell histiocytosis (LCH) are histiocytic diseases that occur most commonly in young children. Improvements in recognition and treatment have been substantial for both diseases in the past decade, although early and late morbidity continue to be major concerns. These two diagnoses behave differently, although the clinical spectra for both diseases are diverse and can lead to confusion and delays in diagnosis and treatment. This article focuses on the clinical and genetic spectrum of FHL as well as the clinical and treatment variations of LCH.

Insights into the pathogenesis of Langerhans cell histiocytosis: the development of targeted therapies

More than a century after its first description, Langerhans cell histiocytosis (LCH) still remains an intriguing disease. Considerable progress in understanding its biology has been achieved recently. Description of the V600E BRAF mutation in samples of LCH tissue in 2010 was followed by description of additional mutations, all leading to constitutive ERK activation. Current experimental data suggest that LCH is a myeloid neoplasia with inflammatory properties, yet the exact pathophysiology remains poorly understood. Disease management paradigms have changed over time, closely reflecting the evolving view of the nature of the disease. The international Histiocyte Society have conducted three prospective clinical studies on multisystem LCH since the early 1990s. The standard frontline therapy for patients with multisystem LCH based on the cumulative knowledge of those trials consists of 6–12 weeks of initial therapy (daily oral steroids and weekly vinblastine injections), followed by pulses of prednisolone/vinblastine every 3 weeks, for a total treatment duration of 12 months. A currently ongoing study (LCH-IV) with a complex design (five interventional and two observational strata) targets further reduction of mortality and morbidity by tailoring treatment intensity depending on expected risk, as well as by exploring treatment regimens for special locations. Current knowledge on LCH pathobiology opens opportunities for improvement in the patient outcome. The activating BRAF and MAP2K1 mutations collectively accounting for about 75% of the LCH population as well as the resulting constitutive activation of downstream ERK offer an opportunity for targeted treatment. Related issues (eg, finding most effective and less toxic drugs or combinations, appropriate dosage, and optimal treatment duration) must be addressed in controlled prospective trials. Additional mechanisms, such as the interactions of the mutated dendritic cell clone with other inflammatory cells and key cytokines and chemokines, still remain attractive targets for therapeutic intervention, particularly in patients with localized, less aggressive disease.

Diverse Cutaneous Presentations of Langerhans Cell Histiocytosis in Children: A Retrospective Cohort Study

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease, frequently affecting young children.

PROCEDURE

We performed a retrospective study in patients younger than 16 years old manifesting with skin symptoms, and documented their different cutaneous lesions and systemic symptoms. We compared subgroups of children with single-system, skin-only, and multisystem disease and sought signs predictive for multisystem disease. In a small sample of patients, BRAF mutations were analyzed in archived biopsies.

RESULTS

A wide spectrum of cutaneous presentations varying from crusted nodules and papules, blisters, vascular tumor-like lesions, scaling orange to red macules (frequently in seborrheic regions) to purpuric macules, and papules was documented in our cohort of 32 children. Otitis externa was a common manifestation and mucosal lesions were seen in three patients. A novel manifestation was a red-blue nodule that appeared in a patient after a vaccination. None of the cutaneous lesions was predictive for the classification or final outcome as a single-system or multisystem disease. However, later onset and a more protracted course of skin lesions were more frequent findings in multisystem LCH. Mucosal lesions and otitis externa were almost exclusively seen in patients with multisystem disease, a finding that warrants further investigation. Both wild-type (WT) and mutated BRAF were found not only in multisystem LCH, but also in skin-only LCH. Two cases with rapidly resolving congenital lesions had WT BRAF.

CONCLUSIONS

Late onset and a protracted course of skin lesions are associated with MS-LCH, whereas WT BRAF is found in rapidly resolving skin lesions.

Langerhans Cell Histiocytosis (LCH) in Egyptian Children: Does Reactivation Affect the Outcome?

OBJECTIVE

To report a single centre outcome of management of Langerhans cell histiocytosis (LCH), a clonal disease with involvement of various body systems.

METHODS

Retrospective analysis of 80 pediatric LCH patients at Children Cancer Hospital-Egypt between July 2007 and December 2011 was performed. Patients were stratified and treated according to LCH III protocol. The median follow up period was 42 mo (range: 1.18 to 71 mo).

RESULTS

At wk 6 and 12, 'better' response was obtained in 61 (76 %) and 74 (93 %) patients respectively. Afterwards, reactivation occurred in 25 patients (38 %), of them multiple episodes occurred in 5 patients (6.25 %), managed by repetition of 1st line treatment for once or more. The 5 y overall survival (OS) and event free survival (EFS) was 96.3 and 55 % respectively. At last follow up, better status was reached in 70 patients, 3 in each 'intermediate' and 'worse' status. Three high risk patients died and one patient was lost to follow up.

CONCLUSIONS

In a single Egyptian pediatric LCH experience, the response to treatment is satisfactory and survival remains the rule except in high risk organs disease that still needs a new molecule for salvage. However in multiple reactivations, patients do well with repetition of the 1st line of treatment with or without methotrexate.

Langerhans Cell Histiocytosis: A Clinicopathologic Review and Molecular Pathogenetic Update

Langerhans cell histiocytosis (LCH) comprises a wide spectrum of clinical disorders that have in common a proliferation of Langerhans-type cells with characteristic morphologic, immunophenotypic, and ultrastructural features. In part because of the diverse clinical manifestations of LCH, there has long been controversy over whether LCH is best considered a reactive process or a neoplasm. Herein, we discuss the clinical and pathologic features of LCH, including recent advances in the understanding of the molecular pathogenesis of this disease that support its categorization as a neoplasm. We also review the implications that these recently described molecular characteristics may have on risk stratification and treatment of LCH.

[Therapy-resistant swelling of the upper eyelid in childhood]

HISTORY

Swelling of the upper eyelid in childhood is caused by a variety of diseases and is very often generated by inflammation but orbital tumors should always be considered in the differential diagnostics.

METHODS

We report about a 4-year-old girl with a drug-resistant swelling of the upper eyelid and ptosis of the right eye. This case report demonstrates the route from initial clinical examination to diagnosis and additionally reviews the current status of therapeutic options.

RESULTS

After magnetic resonance imaging (MRI) and diagnostic excision, Langerhans cell histiocytosis (LCH) could be histologically proven. Visual acuity and levator muscle function improved from 0.5 to 1.25 and from 2 mm to 12 mm, respectively, by amblyopic prophylaxis and immunosuppressive therapy.

CONCLUSIONS

Persistent and drug-resistant swelling of the upper eyelid in childhood is also strongly suspicious for tumors. The suspicion of rare orbital tumors in children can be frequently substantiated by MRI. Biopsy and histological diagnosis are essential to plan adequate treatment and to estimate the prognosis. Particularly in Langerhans cell histiocytosis the methods of choice for over 10 years are specific immunochemical procedures (detection of protein s100 and CD1a).

How I treat Langerhans cell histiocytosis

"Langerhans cell histiocytosis" (LCH) describes a spectrum of clinical presentations ranging from a single bone lesion or trivial skin rash to an explosive disseminated disease. Regardless of clinical severity, LCH lesions share the common histology of CD1a(+)/CD207(+) dendritic cells with characteristic morphology among an inflammatory infiltrate. Despite historical uncertainty defining LCH as inflammatory vs neoplastic and incomplete understanding of mechanisms of pathogenesis, clinical outcomes have improved markedly over the past decades through cooperative randomized clinical trials based on empiric therapeutic strategies. Significant advances include recognition of high- and low-risk clinical groups defined by hematopoietic and/or hepatic involvement, and of the importance of optimal intensity and of duration of chemotherapy. Nevertheless, mortality of high-risk patients, disease recurrence, lack of robustly tested salvage strategies, and significant disease morbidity of both high- and low-risk patients remain challenges. Recent discovery of recurrent somatic mutations in mitogen-activated protein kinase pathway genes at critical stages of myeloid hematopoietic differentiation in LCH patients supports redefinition of the disease as a myeloproliferative disorder and provides opportunities to develop novel approaches to diagnosis and therapy.

Outcomes of children younger than 24 months with langerhans cell histiocytosis and bone involvement: a report from a single institution

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disorder that ranges from single-system to disseminated multisystem disease. Patients younger than 24 months of age more commonly present with risk organ (liver, spleen, hematopoietic system, or lung) involvement at diagnosis and have a poor prognosis. Treatment approaches have changed over the last 25 years. Our goal was to describe the course and outcomes of patients younger than 24 months of age at diagnosis and identify the role of bone involvement in outcomes.

METHODS

We conducted a retrospective chart review of patients diagnosed with LCH at Children's Hospital Los Angeles from 1984 to 2010, focusing on 71 patients younger than 24 months of age at diagnosis.

RESULTS

Ten patients had single bone lesions at diagnosis and did well irrespective of therapy. The majority of patients (40/71 or 56%) had multiple bone lesions. Of the 37 patients with multisystem disease, 27 children (73%) had risk organ involvement. Fourteen patients with risk organ involvement received ≤ 6 months of initial chemotherapy with prednisone and vinblastine. Six of these patients had reactivation of the disease, and bone was the most frequent site of reactivation. Seven patients with risk organ involvement were treated with at least 12 months of chemotherapy. Only one of these patients had reactivation of the disease, and none died. The majority (7/10) of patients with risk organ involvement who progressed on therapy died despite multiple treatment regimens.

CONCLUSIONS

Patients younger than 24 months of age at diagnosis are more likely to have multiple bone lesions than older patients, supporting that a radiographic skeletal survey at the time of LCH diagnosis is important to evaluate the extent of bone involvement. Bones were the most common site for reactivation for all patients. As expected, subjects with risk organ involvement had better outcomes when treated with systemic chemotherapy for at least 1 year.

LEVEL OF EVIDENCE

As a retrospective review of all cases at our institution over a 26-year period, this article represents level IV evidence.

The natural history of skin-limited Langerhans cell histiocytosis: a single-institution experience

INTRODUCTION

Prior reports of Langerhans cell histiocytosis (LCH) suggest that isolated skin involvement is rare and often progresses to systemic disease. More rapid access to pediatric subspecialty care has likely led to more frequent representation of this condition. The purpose of this study is to characterize the natural history of skin-limited LCH in an era of increased access to pediatric subspecialty care.

MATERIALS AND METHODS

A retrospective chart review was performed on all patients newly diagnosed with LCH between 2001 and 2012 at the Children's Hospital of Wisconsin. Extensive review of laboratory, physical examination, and imaging reports was performed and data collected for patients with biopsy-proven skin LCH.

RESULTS

Sixteen individuals with skin-limited LCH were identified. The median age at onset of skin eruption was birth (range, birth to 6 mo), and median duration of follow-up was 19.5 months (range, 2 wk to 10 y) from diagnosis. One patient (6%) developed pituitary disease and 1 patient (6%) had refractory skin involvement. All others experienced complete resolution. For patients without progressive or refractory disease, resolution of skin findings occurred within 7 months from onset.

DISCUSSION

Progression of skin-limited to multisystem LCH likely may be less frequent than previously described.

Differentiating skin-limited and multisystem Langerhans cell histiocytosis

OBJECTIVE

To identify features associated with multisystem involvement and therapeutic failure in patients with skin Langerhans cell histiocytosis (LCH).

STUDY DESIGN

We reviewed medical records of 71 consecutive patients with LCH with skin involvement evaluated at Texas Children's Hospital and analyzed clinical features, laboratory results, and the presence of circulating cells with the BRAF-V600E mutation with respect to initial staging and clinical outcomes.

RESULTS

Skin disease in patients older than 18 months of age at diagnosis was associated with the presence of multisystem disease (OR, 9.65; 95% CI, 1.17-79.4). Forty percent of patients referred for presumed skin-limited LCH had underlying multisystem involvement, one-half of these with risk-organ involvement. Patients with skin-limited LCH had a 3-year progression-free survival of 89% after initial therapy, and none developed multisystem disease. Patients with skin/multisystem involvement had a 3-year progression-free survival of 44% with vinblastine/prednisone therapy, and risk-organ involvement did not correlate with failure to achieve nonactive disease. Circulating cells with BRAF-V600E were detected at higher frequency in patients with multisystem involvement (8 of 11 skin/multisystem vs 1 of 13 skin-limited; P = .002).

CONCLUSION

Skin-limited LCH necessitates infrequent therapeutic intervention and has a lower risk of progression relative to skin plus multisystem LCH. The less-aggressive clinical course and lack of circulating cells with the BRAF-V600E mutation in skin-limited LCH suggest a different mechanism of disease origin compared with multisystem or risk-organ disease.

Primary intramedullary Langerhans cell histiocytosis of the thoracic spinal cord

A 28-year-old male presented with a rare case of primary intramedullary spinal Langerhans cell histiocytosis (LCH) manifesting as the chief complaint of a 6-month history of gait disturbance and back pain, and difficulty with sphincter control. Serial T2-weighted magnetic resonance imaging of the thoracic spine revealed enlargement and intramedullary hyperintensity of the spinal cord at T2 to T4. Biopsy of the lesion was performed. Histological examination of the biopsy specimens verified vascular proliferation and remarkable infiltration of histiocytes that were positive for CD1a, suggesting a diagnosis compatible with LCH. The patient was treated successfully by steroid pulse therapy. LCH is a rare disease that occurs mainly in children and may cause a broad range of manifestations, from a single osseous lesion to multiple lesions involving more than one organ or system. The present case illustrates the unexpected occurrence and important differential diagnosis of primary intramedullary spinal LCH of the thoracic spine in adult patients presenting with progressive paraparesis and back pain.